Higher Peak Load Research Articles

HIGH-RESOLUTION MASS SPECTROSCOPY (HRMS)-A REVIEW

High-resolution mass spectroscopy (HRMS) is a valuable method for evaluating complex and time-consuming matrices, such as human breath, and it's employed to determine the structure's precise mass and chemical structure and elemental composition and identify unknowns and a powerful analytical separation technique. High-resolution mass spectrometry (HR-MS) detects sample matrix to within 0.001 unit of atomic mass. HRMS instrumentation's enhanced resolution allows it to produce fragmentation patterns, which enhances the precision of chemical formula prediction and database comparison for allows for the detection. TOF, Orbitrap, and FT-ICR mass detectors all seem to have a great mass high resolution which may be utilised to achieve maximum data. High-resolution mass spectrometry employs devices able to accurately detecting the density of substances towards the third or fourth significant digit. The Benefit of HR-MS the effectiveness of the approach in the evaluation of complicated mixtures to offer the high peak load required to deliver the accurate molecular weight of the subcomponents. The highest resolution is typically seen in FTICR mass spectrometers. HRMS has transformed how we approach the issue of identifying and monitoring pharmaceutical residues in sophisticated biological materials.

Tight power balance multi-time scale disposal strategy for wind integrated system considering electric vehicle charging station

High wind power penetration and peak load pose significant challenges to the power system in maintaining the power supply–demand balance. Once the power supply–demand balance is disrupted, system load shedding and wind spillage become inevitable. In this study, the aforementioned problem is defined as the tight power balance (TPB) problem. The accuracy of wind power and load forecasting increases with a decrease in the forecasting timescale. Based on the aforementioned characteristics, a TPB multi-timescale disposal strategy for wind-integrated power systems considering electric vehicle (EV) charging stations is established to address the TPB problem at different timescales. First, the operation model of an electric vehicle charging station offering flexible ramping capacity is established. Second, a multi-timescale disposal strategy, which includes an intra-day 4-h plan, an intra-day 1-h plan, and a real-time 15-min plan, is presented by quantifying the flexible demand at different timescales. Finally, the proposed strategy is verified using a modified IEEE 118-bus system. The analysis results show that the proposed TPB multi-timescale disposal strategy effectively promotes the disposal level of the TPB problem.

Periarticular muscle status affects in vivo tibio-femoral joint loads after total knee arthroplasty.

Background: Total knee arthroplasty (TKA) is a highly effective treatment for severe knee osteoarthritis that is increasingly performed in younger, more active patients. As postoperative muscular impairments may negatively affect surgical outcomes and implant longevity, functional muscle recovery gains increasing importance in meeting future patient demands. This study aimed to assess the status of periarticular muscles in the long-term follow-up after TKA and to evaluate its impact on in vivo tibio-femoral joint loads. Methods: A case series was created, with eight patients with knee osteoarthritis. All subjects received an instrumented knee implant in unilateral TKA. Native computed tomography scans, acquired pre and postoperatively, were used to evaluate distal muscle volumes and fatty infiltration. In vivo tibio-femoral joint loads were measured telemetrically during standing, walking, stair climbing and chair rising and were correlated to muscle status. Results: Postoperatively a reduction in fatty infiltration across all periarticular muscles was pronounced. High average peak loads acted in the tibio-femoral joint ranging from 264% during stand-to-sit activities up to 341% body weight (BW) during stair descent. Fatty infiltration of the m. quadriceps femoris and hamstrings were associated with increased tibio-femoral joint contact forces during walking (r = 0.542; 0.412 and 0.766). Conclusion: The findings suggest that a fatty infiltration of periarticular muscles may lead to increased tibio-femoral joint contact forces. However, we only observed weak correlations between these parameters. Improvements in functional mobility and the restoration of a pain-free joint likely explain the observed postoperative reductions in fatty infiltration. Perioperative rehabilitation approaches targeting residual impairments in muscle quality could, contribute to reduced tibio-femoral joint loads and improved long-term outcomes of TKA. However, it has to be pointed out that the study included a small number of patients, which may limit its validity.

Regulated peer-to-peer energy markets for harnessing decentralized demand flexibility

Transactive energy systems use dynamic electricity markets to present an improved way to control large numbers of distributed energy resources while maintaining user privacy, autonomy and scalability. However, this access to dynamic electricity prices can introduce negative emergent behavior like high peak loads if not adequately regulated by grid operators. To solve this, this paper proposes a regulated peer-to-peer market structure for residential prosumers. Prosumers bid energy demand or supply curves into a peer-to-peer market, which can then be directly used by the utility to quantify and dispatch demand flexibility. A utility surcharge mechanism can then be employed to dispatch this flexibility, and achieve significant improvements to reliability. This framework is tested in a simulation environment of electrified residential buildings with significantly enhanced fidelity representing the real-world housing stock. New York State and the month of January was chosen for the demonstration purpose, considering that January is one of the most challenging months for fully electrified systems in cold climates as solar production occurs at opposite times of the highest heating load. Results show that the surcharge can reducing peak load and ramp rates by nearly 50%, while also encouraging consumption of locally generated electricity.

The role of electrification induced peak loads and gas infrastructure constraints on decarbonization pathways in New York State

New York State policies impose time bound targets for both progressively larger emissions reductions and increasing fractions of zero-carbon electricity. This paper compares pathways to meet desired emissions reduction goals with or without specified zero-carbon electricity targets. We show that when an additional lever for reducing emissions – electrification of buildings and transportation – is considered, New York State can meet the same desired emissions targets at considerably lower levelized costs of electricity (LCOEs) if specified zero-carbon electricity targets are relaxed. We also investigate how electrification induced new peak loads and limits on new gas infrastructure impact state decarbonization pathways. To meet the 40% emissions reduction target by 2030, two new illustrative approaches are considered. One pathway with 100% electrification of buildings and vehicles, 11 GW of wind and utility-scale solar capacity and 21 GW of new gas generation capacity leads to an LCOE of $63/MWh. An alternate pathway that precludes new gas generation capacity requires 60% electrification, nearly doubles the installed wind and solar capacity, and results in an LCOE of $72/MWh. Due to the added emissions reduction benefits from electrification, both illustrative pathways are lower cost than a pathway in which the same 40% reduction target is combined with a specified 70% renewable target - at an LCOE of $92/MWh. We also show that LCOEs can be kept manageable through shaving of new higher peak loads that arise from electrified heating. Moreover, the LCOE impact of limiting peak natural gas flow to its current quantities is found to be small.

Application of LoRa Technology at Distribution Substation Using Peak Load Data

The process of monitoring and measuring transformers at PT. PLN (Persero) at the distribution substation BR 391 is done manually during peak load hours in the field, usually between 18.00-22.00 local time. Distribution substations sometimes have different peak load hours, in the morning, afternoon, evening, and sometimes during the day. Taking into account the different peak load hours at different substations, the current peak load hours are still determined by human. It is not effective, to overcome this, in this study it is planned to design a monitor and data storage using LoRa technology to monitor transformers at distribution substations all the time and has been tested at distribution substation BR 391 Jl. Wijaya Kusuma Medan. From the observations, peak load hours occur between 18.00-22.00 WIB and the highest peak load with power per phase: R=20,513,40 watts, S=15,350.06 watts, and T=21,323.91 watts. It can be seen that the highest average daily power consumption is at 20.00 WIB. More load usage occurs at night and the highest load is in the T phase. The increase in load affects the temperature increase of the cable up to 42.6℃

A Novel Lattice Structure for Enhanced Crush Energy Absorption

the energy absorption capacity of a few common lattice structures printed out of PLA using fused deposition modeling and proposes an improved lattice structure. Simple cubic (SC), honeycomb (HC), body-centered cubic (BCC), and novel PeckGy80 (PG80) lattice structures were subjected to compressive tests. The quasi-static load-displacement behavior of lattice specimens was characterized in terms of specific energy absorption and crush load efficiency. The damage mechanisms were then related to energy absorption. Cracks and brittle fractures occurred in all lattice structures during the crush test. Different lattice structures induced different damage mechanisms, significantly affecting their energy absorption. SC lattice structure showed structural separation at a small displacement, rendering it an ineffective energy absorber. BCC and HC lattice structures demonstrated almost identical shear band failure modes. The PG80 lattice structure, although made of brittle PLA, displayed progressive failure from the bottom layer to the upper layers, exhibiting both a high peak load and stable post-yield behaviour. This damage mode enabled the PG80 lattice to be far superior in terms of specific energy absorption to HC, SC, and BCC lattice structures.

Development of a novel Macaque-Tropic HIV-1 adapted to cynomolgus macaques.

Macaque-tropic HIV-1 (HIV-1mt) variants have been developed to establish preferable primate models that are advantageous in understanding HIV-1 infection pathogenesis and in assessing the preclinical efficacy of novel prevention/treatment strategies. We previously reported that a CXCR4-tropic HIV-1mt, MN4Rh-3, efficiently replicates in peripheral blood mononuclear cells (PBMCs) of cynomolgus macaques homozygous for TRIMCyp (CMsTC). However, the CMsTC challenged with MN4Rh-3 displayed low viral loads during the acute infection phase and subsequently exhibited short-term viremia. These virological phenotypes in vivo differed from those observed in most HIV-1-infected people. Therefore, further development of the HIV-1mt variant was needed. In this study, we first reconstructed the MN4Rh-3 clone to produce a CCR5-tropic HIV-1mt, AS38. In addition, serial in vivo passages allowed us to produce a highly adapted AS38-derived virus that exhibits high viral loads (up to approximately 106 copies ml-1) during the acute infection phase and prolonged periods of persistent viremia (lasting approximately 16 weeks postinfection) upon infection of CMsTC. Whole-genome sequencing of the viral genomes demonstrated that the emergence of a unique 15-nt deletion within the vif gene was associated with in vivo adaptation. The deletion resulted in a significant increase in Vpr protein expression but did not affect Vif-mediated antagonism of antiretroviral APOBEC3s, suggesting that Vpr is important for HIV-1mt adaptation to CMsTC. In summary, we developed a novel CCR5-tropic HIV-1mt that can induce high peak viral loads and long-term viremia and exhibits increased Vpr expression in CMsTC.

Performance Study of Concrete Beam-Column Joints in Building Steel Structures Under High-Intensity Vibration

In order to minimize the loss of life and property in an earthquake, the beam-column joints of buildings need to have good seismic performance. This paper briefly introduced concrete beam-column joints and used a steel skeleton to strengthen the seismic performance of concrete beam-column joints. The concrete beam-column and reinforced concrete beam-column joints were prepared for experimental analysis. The skeleton curve and energy dissipation capacity of the joints were tested using quasi-static loading experiments. The relative displacement of the column at different heights in the beam-column joints was tested under an eight-degree earthquake simulated by a vibration table. The results showed that the reinforced concrete beam-column joint had higher peak loads and ultimate displacements when the quasi-static loading displacement exceeded the yield displacement; the reinforced concrete beam-column joint had stronger energy dissipation capacity in the face of cyclic loads; the reinforced concrete beam-column joint had smaller relative column displacements in the face of an eight-degree earthquake.

Binary-phase service battery energy storage system strategy for peak demand shaving and enhanced power quality

Owing to nonlinear and large consumer loads, power grid system operators encounter major challenges in matching the generated power supply to consumer power demand to smooth out the high-peak load demands and mitigate the voltage and current disturbances within the electrical grid. A battery energy storage system (BESS) is employed as a two-phase control technique to minimize the peak load demand of the system and enhance the power quality within the electrical grid system. The phase I control strategy presents a robust artificial neural network control, which is implemented considering the BESS state-of-charge (SoC) and operation time-of-day (ToD) of the customers’ loads to identify load peaks at each period of the day to effectively reduce the high-load demand. Moreover, in the phase II control strategy, a customized BESS-hybrid series-shunt active power filter (B-HSSAF) is presented to effectively mitigate the grid disturbances, which results in an enhanced grid system as suggested by the simulation results. The total harmonic distortion values after compensation using the B-HSSAF satisfy IEEE standard 519, and the power grid is enhanced. Furthermore, qualitative discussions of the optimal location of the BESS and dynamic thermal rating integration which are limitations of this paper are concisely presented with recommended further studies that can be taken into consideration.

A hierarchical clustering approach for examining potential risk factors for bone stress injury in runners

Bone stress injuries (BSI) are overuse injuries that commonly occur in runners. BSI risk is multifactorial and not well understood. Unsupervised machine learning approaches can potentially elucidate risk factors for BSI by looking for groups of similar runners within a population that differ in BSI incidence. Here, a hierarchical clustering approach is used to identify groups of collegiate cross country runners (32 females, 21 males) based on healthy pre-season running (4.47 m·s−1) gait data which were aggregated and dimensionally reduced by principal component analysis. Five distinct groups were identified using the cluster tree. Visual inspection revealed clear differences between groups in kinematics and kinetics, and linear mixed effects models showed between-group differences in metrics potentially related to BSI risk. The groups also differed in BSI incidence during the subsequent academic year (Rand index = 0.49; adjusted Rand index = −0.02). Groups ranged from those including runners spending less time contacting the ground and generating higher peak ground reaction forces and joint moments to those including runners spending more time on the ground with lower loads. The former groups showed higher BSI incidence, indicating that short stance phases and high peak loads may be risk factors for BSI. Since ground contact duration may itself account for differences in peak loading metrics, we hypothesize that the percentage of time a runner is in contact with the ground may be a useful metric to include in machine learning models for predicting BSI risk.

Pain prevalences and analgesic use in junior athletes – a recent narrative review

Problem: Children and adolescents are exposed to high peak loads at an early age in junior competitive sports. Little is known in this age group about the injury-free occurrence of pain and the sport-related consumption of painkillers. Methodology: Narrative review with multivariate and paired keyword search for studies that evaluated localization-dependent, injury-free prevalence of pain, analgesic use, and determinants of use in junior competitive sports. Results: Derived from the few existing studies, a pronounced willingness to participate in competitions and training despite pain (“playing hurt”) is found in junior competitive sports among injury-free junior athletes. Analogous to adult competitive sports, analgesics, especially from the group of non-steroidal anti-inflammatory drugs, are used at an early stage. Especially in adolescents with increasing performance progress, in particular female athletes, the use of analgesics for joint pain has been documented. The consumption takes place for the compensation of post-exposure pain conditions but also prophylactically. The use of analgesics and the decision to take them are influenced by the immediate care environment in 2/3 of cases. A physician is involved in only 1 of 3 analgesic use decisions. Discussion: For exertional pain, a displacement mentality exists among many stakeholders in the junior setting. There is early, with age increasingly uncritical and excessive analgesic use. This consumption behavior harbors a high potential for abuse due to self-defined indications, procurement, dosage and duration of use. There is an individual need for a stronger appreciation of pain conditions by the caregivers in junior competitive sports with early consultation with a doctor, combined with the question of how much pain is allowed.

Optimization scheduling of home appliances in smart home: A model based on a niche technology with sharing mechanism

Smart appliances bring convenience to people’s lives, but the high electricity cost and high peak load are still drawbacks. The scheduling optimization of household electricity tasks can effectively alleviate those drawbacks. Therefore, this paper proposes a scheduling optimization model of smart home appliances to reduce the load peak value and electricity cost. Herein, the electricity tasks are defined by the set theory and classified by the operational characteristics of the loads. Then, a hybrid coding genetic algorithm based on the niche technology is proposed for scheduling optimization problems of electricity tasks. Different coding and cross-mutation operation strategies are designed for different electricity tasks. Finally, a tracing Pareto method based on weighted sum approach is proposed to solve the multi-objective optimization problem. The experimental results show that the proposed algorithm has a good performance in reducing load peaks and electricity costs. In cases A, B, and C, the load peak value is reduced by 54.7%, 45.7%, and 20.7%, respectively; the electricity cost is reduced by 5.98%, 12.00%, and 16.12%, respectively. Furthermore, a series of Pareto optimal solutions are also identified, which can help users better understand the trade-off relation between the load peak value and electricity cost.

Interfacial design and flexural property of CFRP/aluminum-honeycomb sandwich with Aramid-pulp micro/nano-fiber interlays

This study proposes three interfacial designs for CFRP/aluminum-honeycomb sandwich to enhance interlayer of CFRP panels and adhesive interface between CFRP panel and honeycomb using sparsely distributed Aramid-pulp (AP) micro-/nano-fibers as interlayers. In laminar CFRP, AP-fiber free-ends protruded into adjacent carbon-fiber plies generate strong cross-ply fiber-bridging to prevent premature delamination. Adhesive joints with AP at the interfaces between CFRP and honeycomb form in-situ fillets and a randomly AP-reinforced composite layer. Meanwhile, Resin Pre-Coating (RPC) on the sanded CFRP and honeycomb core is used to improve the bonding capacity and create rounded fillet joints at the honeycomb edge. Three-point-bending tests show the sandwiches with toughened interfacial designs have higher peak load (+43.04%–57.60%), post-peak average load (+28.38%–163.25%) and energy-absorption (+15.52%–81.69%). The AP-toughened sandwich with 8-plies CFRP is stronger than the common sandwich with 10-plies even 12-plies CFRP. Failure and toughening mechanisms from both interfaces (e.g., delamination with fiber-bridging, matrix cracks in CFRP, debonding, cohesive failure with fiber-bridging, pulling-up of fiber, buckling of core, etc.) were explained by micrographs combined with schematic illustration.

Review of Fast Charging for Electrified Transport: Demand, Technology, Systems, and Planning

As the number and range of electric vehicles in use increases, and the size of batteries in those vehicles increases, the demand for fast and ultra-fast charging infrastructure is also expected to increase. The growth in the fast charging infrastructure raises a number of challenges to be addressed; primarily, high peak loads and their impacts on the electricity network. This paper reviews fast and ultra-fast charging technology and systems from a number of perspectives, including the following: current and expected trends in fast charging demand; the particular temporal and spatial characteristics of electricity demand associated with fast charging; the devices and circuit technologies commonly used in fast chargers; the potential system impacts of fast charging on the electricity distribution network and methods for managing those impacts; methods for long-term planning of fast charging facilities; finally, expected future developments in fast charging technology and systems.

Damage-Based Assessment of the Fatigue Crack Initiation Site in High-Strength Steel Welded Joints Treated by HFMI

This study aimed to identify the fatigue crack initiation site of high-frequency mechanical impact (HFMI)-treated high-strength steel welded joints subjected to high peak stresses; the impact of HFMI treatment residual stress relaxation being of particular interest. First, the compressive residual stresses induced by HFMI treatment and their changes due to applied high peak stresses were quantified using advanced measurement techniques. Then, several features of crack initiation sites according to levels of applied peak stresses were identified through fracture surface observation of failed specimens. The relaxation behavior was simulated with finite element (FE) analyses incorporating the experimentally characterized residual stress field, load cycles including high peak load, improved weld geometry and non-linear material behavior. With local strain and local mean stress after relaxation, fatigue damage assessments along the surface of the HFMI groove were performed using the Smith–Watson–Topper (SWT) parameter to identify the critical location and compared with actual crack initiation sites. The obtained results demonstrate the shift of the crack initiation most prone position along the surface of the HFMI groove, resulting from a combination of stress concentration and residual stress relaxation effect.

Seismic behavior of corrugated double-skin composite wall (DSCW) with concrete-filled steel tubes: Experimental investigation

This paper presents the seismic behavior of corrugated double-skin composite wall (DSCW) with concrete-filled steel tube boundary elements. Fifteen 1/3-scale DSCW specimens, varying in shear span ratio, axial compression ratio, corrugation direction and shape, connector type and steel faceplate profile, were tested under cyclic loading. All specimens except W15 failed in flexural failure. The cyclic response of vertical corrugated DSCW was much better than that of horizontal corrugated DSCW. Compared to flat DSCW, corrugated DSCW, even with a 20% reduction in the concrete cross-sectional area, had considerably higher peak load, ductility ratio and energy dissipation. The setting of connectors slowed down the damage rate of the corrugated DSCW in the failure stage, and also significantly improved the peak load and ductility of the corrugated DSCW with λ = 1.5. Increasing the shear span ratio significantly reduced the peak load and initial stiffness of the DSCW, but did not affect the ductility and energy dissipation. The corrugated DSCW, failed in flexural-dominated mode, had excellent collapse resistance, achieving a drift ratio exceeding 2% and a ductility ratio greater than 3.3, and it was recommended to take n = 0.3 as the limit value of axial compression ratio of corrugated DSCW. Moreover, the average ratio of Pt/Pc was 1.082 with a mean absolute error of 0.068 and a root mean square error of 0.084, indicating that the calculated value of proposed formulas for calculating the lateral strength of vertical corrugated DSCW can reflect the measured data well.

Time of use electricity pricing in power system planning and operation: Case study of Nepalese power system

The difference between load demand in the off-peak and peak period is usually high in the context of Nepal, and the high peak load for a short time is the main reason for insufficiency in electricity, frequent electricity outage, and poor power quality. This paper investigates the effectiveness of the time of use (TOU) strategy to reduce peak demand and to improve power quality. TOU electricity price is one of the electric demand response (DR) strategies, which may motivate the customers to reduce their consumption in peak periods and shift load in the off-peak period, which propel the electricity industry towards a higher efficiency compared to that of common flat prices. In this paper, a process based on an equal step length iteration algorithm is used to obtain an optimal period partition. Using the particle swarm optimization (PSO) algorithm, a TOU-based optimization model is proposed to find the optimal electricity price. Then, its impact on peak demand reduction and voltage fluctuation is analyzed. The impact of TOU price on peak demand reduction is investigated in the hourly load profile of Nepal, which indicates the significant reduction in peak demand. Similarly, the impact on voltage fluctuation is analyzed through a case study of the IEEE 33-bus radial distribution test system, which shows voltage profile is improved.

Effects of BFRP Bar Diameter and Cover Thickness on Fracture Behavior of BFRP Bar–Reinforced Ecological High-Ductility Cementitious Composites

Abstract To obtain the design parameters of bridge deck link slabs made of ecological high-ductility cementitious composite (Eco-HDCC) material reinforced with a basalt fiber-reinforced plastic (BFRP) by applying fracture mechanics concepts, the reinforcing effects of a BFRP bar on the fracture properties of BFRP bar–reinforced Eco-HDCC specimens were studied. First, cracking load, crack mouth opening displacement (CMOD), and deflection of specimens were monitored, and BFRP bar diameter and cover thickness were considered. The results indicate that both the diameter and cover thickness of BFRP bar have an obvious influence on the crack kinking angle. In addition, as the diameter of BFRP bar increases, the peak load, peak CMOD, peak deflection, and fracture energy of Eco-HDCC specimens increase, and these peak values of Eco-HDCC specimens after reloading also show the same trend. In addition, the peak load, peak CMOD, peak deflection, and fracture energy are larger if the Eco-HDCC specimen has a smaller cover thickness. However, the Eco-HDCC specimen with a BFRP bar cover thickness of 25 mm has a higher peak load after reloading than the specimen with a cover thickness of 15 mm when the bar diameters are 10 and 12 mm, respectively. In conclusion, BFRP bar diameters from 10 to 14 mm and a cover thickness of 25 mm are recommended when designing bridge deck link slabs.

Reversed-Torsion-Type Crush Energy Absorption Structure and Its Inexpensive Partial-Heating Torsion Manufacturing Method Based on Origami Engineering

Abstract Current vehicle energy absorbers face two problems during a collision in that there is only a 70% collapse in length and there is a high initial peak load. These problems arise because the presently used energy-absorbing column has no deployment shrinkage function. It has been shown that a column called the Reversed Spiral Origami Structure (RSO) developed by Nojima solves the above two problems. However, in the case of the existing technology of the RSO, the forming cost of hydroforming is too expensive for application to a real vehicle structure. Therefore, a new structure imitating RSO, named the Reversed Torsion Origami Structure (RTO), has been developed, which has excellent energy absorption in simulation. Here, a manufacturing system is developed for the RTO cheaply. Excellent results are obtained also in a physical experiment. The RTO can replace conventional energy absorbers and is expected to be widely used in not only automobile structures but also building structures.