Total Power Level Research Articles

Innovative Approaches to Mitigating Noise Pollution from Electric Power Generators: Design Modifications for Enhanced Sound Control

Aims: The noise emanating from high sound power electric generators has adverse effects on human health. In this view, this paper reports a modification that can be done to reduce this high levels of noise to a permissible noise limit. Place and Duration of Study: This study identified the major source and levels of noise emission from selected electric power generators sampled in Ile-Ife, Osun-State, Nigeria. Also determined the controlling parameters of the identified source and modified the identified parameters for low noise generation. Methodology: Noise assignment was carried out on Four (4) medium size electric power generating sets using ATP: MODEL MT- 901A sound measuring instrument at distance of about one centimeter. The major sources of noise emission were investigated on the four selected generating sets. The source of noise from these generating sets was further analysed to identify the major controlling parameters of the identified source. Theoretical modification was done based on these identified parameters for low noise generation. Results: The results of the findings showed that at silencer length of 46.5, 44.0 and 41.2 centimeter, the total sound power levels of the sampled generating sets will be 50, 55 and 60 decibels respectively which is within the permissible noise limits of World Bank.

Underwater radiated noise numerical analysis of polar transport vessels under ship-ice-water-air coupling continuous icebreaking based on the S-ALE algorithm

With the gradual opening of the Arctic channel, the underwater radiated noise induced by the ship-ice collision cannot be ignored. However, the underwater radiated noise induced by ship-ice collision is significantly different from that of ships navigating in open water. To explore the response rule of transient underwater radiation noise induced by ship-ice collision, this paper proposes a simplified numerical analysis method of ship-ice collision-induced transient underwater radiated noise in the full frequency band by combining the explicit dynamic method and acoustic analysis method. The ship-ice-water-air coupled collision analysis method based on the S-ALE algorithm is used to simulate and verify the ice load in the process of ship-ice continuous collision at different speeds. Then, the frequency-domain acoustic analysis method is used to predict the transient underwater radiated noise response in the full frequency band under icebreaking excitation and evaluate it by referring to the steady-state underwater radiated noise standard. The results show that the simplified analysis method can effectively predict the transient underwater radiation noise under icebreaking excitation. Under the icebreaking excitation, the radiation shape is irregularly scattered and the radiation direction is concentrated towards the bottom and bow of the ship with the frequency increase. The influence range of transient underwater radiated noise is mainly within 1000 Hz at different speeds, and the variation in the ship's speed affects the amplitude of the sound power level and the smoothness of the periodic response. The synthesized total sound power levels are 172.56 dB (V = 2.0kn), 174.15 dB (V = 2.5kn), 175.70 dB (V = 3.0kn), and 182.49 dB (V = 4.0kn), respectively. According to the comparison with the evaluation standard, it is found that the transient underwater radiation noise induced by ship icebreaking has a greater impact on marine organisms. It should give more detailed requirements within 10–1000 Hz when using relevant standards to evaluate underwater radiated noise induced by polar icebreaking. This paper can provide a reference for the research of underwater radiated noise induced by ship-ice collision and the formulation of relevant standards.

Postoperative pain relief quality after cesarean section using a stress monitor (Neon FSC system): prospective single-center randomized clinical comparative study

BACKGROUND: The objective assessment of pain levels during labor, postpartum period, and effectiveness of analgesic response remains difficult. We suppose that the dynamics of the activity of the sympathetic nervous system by measuring the galvanic skin response may become a promising method for solving this problem.
 OBJECTIVE: To evaluate the effectiveness of various multimodal analgesia regimens after cesarean section using the NeonFSC stress monitoring system.
 MATERIALS AND METHODS: A prospective single-center clinical comparative study was conducted to evaluate the effectiveness of various postoperative multimodal analgesia regimens in 48 postpartum women who underwent elective cesarean section under spinal anesthesia. For postoperative analgesia, group 1 (n=24) underwent a TAP block, and ketorolac and tramadol were prescribed, and group 2 (n=24) received only ketorolac and tramadol. Randomization was made using the envelope method. The visual analog scale (VAS) and NeonFSC system were used to assess the effectiveness of postoperative pain relief. The observation time was 19–22 h.
 RESULTS: The patients were comparable in age, gestational age, physical status, method of pain management and delivery. At baseline and during the 2-h postoperative period, the median and distribution of visual analogue scale pain scores did not show a statistically significant difference between groups. During the study period, the highest level of spectral power of skin conductance (SC) was recorded in group 2. Baseline skin conductance variability (SCV) values were comparable between groups (p 0.001). Lower SCV values were noted in patients of group 1, compared to group 2, at night (p=0.003 vs p 0.001). The median values of the level of total spectral power of skin conductivity (DASS) in patients of group 1 were 1.5–2 times lower, starting from the second hour until the end of observation.
 CONCLUSION: The NeonFSC system can be a component of an objective assessment of the effectiveness of analgesia after cesarean section.

Acoustic Radiation of a Beam Subjected to Transverse Load

In this paper, the dynamic response of a Euler–Bernoulli beam subjected to transverse harmonic forces is calculated. The method of separation of variables combined with the mode shape superposition method, which includes the determination of eigenvalues, is used to define the velocity field of the beam surface. The Rayleigh integral was used to calculate the sound radiation and the beam was placed in an infinite baffle. Additional actuators are introduced in order to minimize the sound radiation, or, more specifically, the total sound power level of the vibrating beam, and their optimal position and force amplitude are determined; the conclusions were drawn from the optimization results. This paper proposes a method for faster determination of the optimal actuator parameters in order to achieve the minimum total sound power level. The validity of the obtained results is demonstrated with examples, whose solutions are compared to the results in the published literature.

Analysis of loss of cooling accident in VVER-1000/V446 spent fuel pool using RELAP5 and MELCOR codes

Following the Fukushima nuclear disaster, the simulation of accidents in the spent fuel pool has become more noticeable. Despite the low amount of decay heat power, the consequences of the accidents in a spent fuel pool (SFP) can be severe due to the high content of long-lived radionuclides and lack of protection by the pressure vessel.In this study, the loss-of-cooling accident (LOFA) for the VVER-1000/V446 spent fuel pool is simulated by employing RELAP5 and MELCOR 1.8.6 as the best estimate and severe accident analysis codes, respectively. For two cases with different total power levels, decay heat of spent fuels is calculated by ORIGEN-II code. For modeling SFP of a VVER-1000, a qualified nodalizations are considered in both codes. During LOFA in SFP, the key sequences such as heating up of the pool water, boiling and reducing the water level, uncovering the spent fuels, increasing the temperature of the spent fuels, starting oxidation process (generating Hydrogen and extra power), the onset of fuel melting, and finally releasing radionuclides are studied for both cases. The obtained results show a reasonable consistency between the RELAP5 and MELCOR codes, especially before starting the oxidation process.

DWDM signals noise immunity evaluation in a nonlinear fiber-optic path

The total influence of self-phase modulation, phase cross-modulation and four-wave mixing effects and amplified spontaneous emission noise on transmitted pulsed signals noise immunity in a multichannel fiberoptic transmission system with spectral division multiplexing is investigated. The investigation is carried out under the conditions of transmitting system parameters variation: the total optical power level in optical fiber, the transmission speed and the number of spectral channels. The estimate criterion of transmitted pulsed signals noise immunity is Q-factor. The total Q-factor value dependence on the total optical power level in optical fiber for various transmission speed and the number of spectral channels is demonstrated.

Antidiabetic and neuroprotective effects of a novel repaglinide analog.

Repaglinide (RPG) is an oral insulin secretagogue used in the treatment of diabetes. In this study, a new RPG analog was synthesized. Its antidiabetic and neuroprotective effects on dorsal root ganglions (DRG) in streptozotocin (STZ)-induced diabetic rats were examined compared to RPG. To assess the effects of 2-methoxy-4-(2-((3-methyl-1-(2-(piperidin-1-yl)phenyl)butyl)amino)-2-oxoethoxy)benzoic acid(OXR), the impact of OXR on oxidative stress biomarkers, motor function, and the expression of the glutamate dehydrogenase1 (GLUD1), SLC2A2/glucose transporter 2(GLUT2), and glucokinase(GCK) genes in STZ-induced diabetic rats were assessed. DRGs were examined histologically using hemotoxylin and eosin staining. Molecular docking was used to investigate the interactions between OXR and the binding site of RPG, the ATP-sensitive potassium (KATP) channel. Following 5 weeks of treatment, OXR significantly increased the level of total antioxidant power, decreased reactive oxygen species, and lipid peroxidationin the DRGs of diabetic rats. OXR restored STZ-induced pathophysiological damages in DRG tissues. Administration of OXR improved motor function of rats with diabetic neuropathy. Administration of 0.5 mg/kg OXR reduced blood glucose while promoting insulin, mainly through upregulation of messenger RNA expression of GLUD1, GLUT2, and GCK in the pancreas. Molecular docking revealed a favorable binding mode of OXR to the KATP channel. In conclusion, OXR has neuroprotective effects in diabetic rats by lowering oxidative stress, lowering blood glucose, and stimulating insulin secretion. We report that 0.5 mg/kg OXR administration was the most effective concentration of the compound in this study. OXR may be a promising target for further research on neuroprotective antidiabetic molecules.

An ultrasonically actuated fine-needle creates cavitation in bovine liver.

Ultrasonic cavitation is being used in medical applications as a way to influence matter, such as tissue or drug vehicles, on a micro-scale. Oscillating or collapsing cavitation bubbles provide transient mechanical force fields, which can, e.g., fractionate soft tissue or even disintegrate solid objects, such as calculi. Our recent study demonstrates that an ultrasonically actuated medical needle can create cavitation phenomena inside water. However, the presence and behavior of cavitation and related bioeffects in diagnostic and therapeutic applications with ultrasonically actuated needles are not known. Using simulations, we demonstrate numerically and experimentally the cavitation phenomena near ultrasonically actuated needles. We define the cavitation onset within a liver tissue model with different total acoustic power levels. We directly visualize and quantitatively characterize cavitation events generated by the ultrasonic needle in thin fresh bovine liver sections enabled by high-speed imaging. On a qualitative basis, the numerical and experimental results show a close resemblance in threshold and spatial distribution of cavitation. These findings are crucial for developing new methods and technologies employing ultrasonically actuated fine needles, such as ultrasound-enhanced fine-needle biopsy, drug delivery, and histotripsy.

Parametric Analysis of Structural Noise of Steel-Concrete Composite Slab Beams

In this study, the vibration acceleration and radiation structure noise in specific points, 30 cm away from the center surface of each plate of the concrete deck, web, and flange of the steel beam, are measured via the hammering test. The test is conducted on the middle concrete deck of an 8.5 m steel-concrete composite slab beam. The accuracy of the numerical model is then carefully justified. The influence of the number of shear studs, spacing, and arrangement of ribs on the concerning results is methodically examined and discussed by employing the numerical model. In the center frequency of 10–1000 Hz, the total sound power level of the structure can be lessened by improving the concrete deck thickness as well as the number of shear studs. The reduction of the rib spacing can effectively lessen the sound power level as well. The noise reduction of the plate with rib arrangement in the midspan zone is more influential than the case with uniform layout in the whole span.

Protective Effects of Vitamin D on Testicular Tissue, Oxidative Stress and Apoptotic Genes Expression in Rats Treated with Simvastatin

Background & Objective: Cardiovascular diseases (CVDs) are the deadliest disease globally, which in order to reduce this mortality rate statin has been used during last decades. In line, it has been revealed that statins negatively affect testicular tissue. Thus, in the current project, we aimed to investigate the vitamin D protective effects during simvastatin (SIM) administration. Materials & Methods: In this project, 48 male mature Wistar rats were randomly divided into 6 control and experimental groups. The experimental groups were subdivided into Low and High dose SIM-received and Vitamin D co-treated SIM-received groups. After 45 days, the body weight of the animal groups was measured and then they were euthanized and testicles were removed. The right testicular tissue was fixed in fixative solution, while the left testicular tissue was used for biochemical and molecular analysis. To evaluate the pathological changes, hematoxylin and Eosin (H&E) staining were performed. The Malondialdehyde (MDA), Total antioxidant capacity (TAC), catalase (CAT) and Ferric-reducing antioxidant power (FRAP) levels were examined in order to evaluate the Reactive oxygen species (ROS) and antioxidant levels. Finally, Bax, Bcl-2, p53 and Caspase-3 mRNA levels were analyzed using real- time PCR. Result: Our observations revealed that the MDA, Bax, p53 and caspase-3 level enhanced in the sole-SIM-received groups compared to control group, while level of TAC, catalase and Bcl-2 diminished in SIM-received groups versus control group. In contrast, Vitamin D-co-treated animals showed a significant enhancement in level of TAC, catalase and Bcl-2 compared to sole-SIM-received animals (p≤0.05). Conclusion: The vitamin D-co-administration can positively protect testicular tissue against SIM-induced oxidative stress condition by enhancing enzymatic activity of antioxidant defense and anti-apoptotic genes activation.

Neuroprotective Effect of Apigenin on Depressive-Like Behavior: Mechanistic Approach.

Apigenin, as a natural flavonoid present in several plants is characterized with potential anticancer, antioxidant, and anti-inflammatory properties. Recent studies proposed that apigenin affects depression disorder through unknown mechanistic pathways. The effects of apigenin's anti-depressive properties on streptozocin-mediated depression have been investigated through the evaluation of behavioral tests, oxidative stress, cellular energy homeostasis and inflammatory responses. The results demonstrated anti-depressive properties of apigenin in behavioral test including forced swimming and splash tests and oxidative stress biomarkers such as reduced glutathione, lipid peroxidation, total antioxidant power and coenzyme Q10 levels. Apigenin, also, demonstrated its regulatory potency in cellular energy homeostasis and immune system gene expression through inhibiting Nlrp3 and Tlr4 overexpression. Furthermore, failure in energy production as the key factor in various psychiatric disorders was reversed by apigenin modulating effect on AMPK gene expression. Overall, 20mg/kg of apigenin was recognized as the dose suitable for minimizing the undesirable adverse effects in the STZ-mediated depression model proposed in this study. Our data suggested that apigenin could be able to adjust behavioral dysfunction, biochemical biomarkers and recovered cellular antioxidant level in depressed animals. The surprising results were achieved by raise in COQ10 level, which could regulate the overexpression of the AMPK gene in stressful conditions. The regulatory effect of apigenin in inflammatory signaling pathways such as Nlrp3, and Tlr4 gene expression was studied at the surface part of the hippocampus.

Effect of the rotor blade installation angle on the structure-borne noise generated by adjustable-blade axial-flow fans

The effect of rotor blade installation angle on the structure-borne noise of adjustable-blade axial-flow fans is analyzed based on the fluid–solid coupling method. The co-simulation environment ANSYS Workbench is adopted to perform one-way fluid–solid coupling analysis. Following this, the properties of the flow field and noise field with different installation angles are simulated. The flow field simulation results reported significant vorticity near the rotor and stator, and a larger installation angle may cause higher pressure fluctuation. The sound field results showed that the frequency spectrum characteristics for the sound pressure level and the sound power level are almost the same while the installation angle changes from −8° to 8°, and the peaks of frequency spectrum occur at the blade passing frequency and its harmonics. The total sound pressure level (TSPL) and the total sound power level (TPWL) all show increasing trends ranging from −8° to +8°. The maxima of TSPL and TPWL reach 134.1 and 176 dB, while their minima reach 123.1 and 163 dB, respectively. Thus, reduction of the installation angle can reduce the structure-borne noise. Besides, the structure-borne noise generated by adjustable-blade axial-flow fans is low-frequency noise, which lies in the range of 0–500 Hz.

Application of ultrasound in regeneration of silica gel for industrial gas drying processes

Industrial gas dehumidification contributes to a considerable portion of the total industrial energy consumption. Depending on the desired level of dryness, solid desiccants can be a more suitable dehumidification method compared to the conventional dehumidification processes. In this study, the ultrasound-enhanced regeneration of silica gel as a substitute to conventional heating methods is investigated. To analyze the energy-savings effect of applying ultrasound a method of constant total power levels of 20 and 25 (W) corresponding to total specific power levels of 327 and 409 was adopted and for each Watt of applied ultrasonic power, the same amount was deducted from thermal power. The moisture content and regeneration temperature were measured and compared in ultrasound-assisted and non-ultrasound (heat-only) regeneration processes. Experimental results showed that applying ultrasound along with thermal power improves the regeneration process and reduces the energy required to regenerate silica gel by as much as 26%. Various transport modes contributing to mass diffusion in porous media are analyzed and an apparent diffusion coefficient for porous media that includes ultrasonication effects is proposed. Regarding regeneration temperature, with application of ultrasound, regeneration at lower temperatures by as much as ∼11% was achieved.

Spatial optimisation of mango leather production and colour estimation through conventional and novel digital image analysis technique

Being a seasonal fruit mango cannot be cherished over the year; dehydration may be a solution to preserve the deliquesce of mango as mango leather. The processing parameters like puree load (0.4–0.6 g/cm2), total soluble solid (20–30 °B), oven temperature (60–80 °C), and microwave power level (100–300 W) were optimised for a superior textural attribute (hardness) primitive drying method like sun drying, industrially practiced modern methods like hot air oven drying and microwave drying and cutting-edge drying technique like freeze-drying. Response surface methodology and artificial neural network technique were adapted to model these drying procedures by considering the central composite design. The mathematical operations guiding to describe the model were studied. Being an imperative parameter colour quantification is essential for food industries. Current research employs microwave drying to produce mango leather with colour quantification approach. The L, ‘a’ and ‘b’ values of the product have been measured by Hunter Lab colorimeter and by digital image analysis, to determine the chromatic view harmonious to human vision. The relative analysis of colour measurement through these two techniques has been studied.

Comparison of Single Vehicle Noise Emission Models in Simulations and in a Real Case Study by means of Quantitative Indicators

Road traffic has a significant influence on the environmental noise pollution, producing harmful effects on human health and collective well-being. Since noise measurements cannot be performed everywhere, or even in a large number of sites, because of high costs and time consumption, traffic noise predictions are necessary for noise abatement and control. Consequently, many scientific models have been developed in recent years focusing on this aspect with the definition of source emission and sound propagation empirical formulations exclusively. This paper focuses on some Emission Models, describing the comparison of the results, in terms of sound power level emitted by a single vehicle, obtained with their application to different simulations of driving conditions and to two real study cases. After a preliminary comparison between the models, the evaluation of two indicators, namely the average and total source power level, will be discussed in relation to different conditions of the vehicle kinematics. The application of these two indicators to real study cases will demonstrate their validity. It will be shown that this procedure can become a tool for supporting people route choices according to a less impact of environmental noise. This will open the way to new scenarios of eco-routing, by means of implementation of models prediction in dedicated software platforms and/or in car navigation systems.

Evaluation of Single Vehicle Noise Emission in Different Speed Conditions

Because of the increase of vehicles number, the evaluation and monitoring of road traffic noise assume a significant role for decreasing risks for human health and managing environmental pollution in urban areas. Noise measurements cannot be performed everywhere, or even in a large number of sites, because of high costs and time consumption. For this reasons, Road Traffic Noise predictive Models (RTNMs) can be implemented to estimate the noise levels, knowing certain parameters needed as input. This paper describes the comparison of the results, in terms of sound power level emitted by a single vehicle, obtained with the application of some Emission Models (EMs) to different simulations of driving conditions. After a preliminary comparison between the models, the evaluation of two indicators, namely the average and total source power level, will be discussed in relation to different conditions of the vehicle kinematics.

Resting theta activity is associated with specific coding levels in event-related theta activity during conflict monitoring.

Brain electrical activity in the theta frequency band is essential for cognitive control (e.g., during conflict monitoring), but is also evident in the resting state. The link between resting state theta activity and its relevance for theta‐related neural mechanisms during cognitive control is still undetermined. Yet, theoretical considerations suggest that there may be a connection. To examine the link between resting state theta activity and conflict‐related theta activity, we combined temporal EEG signal decomposition methods with time‐frequency decomposition and beamforming methods in N = 86 healthy participants. Results indicate that resting state theta activity is closely associated with the strength of conflict‐related neural activity at the level of ERPs and total theta power (consisting of phase‐locked and nonphase‐locked aspects of theta activity). The data reveal that resting state theta activity is related to a specific aspect of conflict‐related theta activity, mainly in superior frontal regions and in the supplemental motor area (SMA, BA6) in particular. The signal decomposition showed that only stimulus‐related, but not motor‐response‐related coding levels in the EEG signal and the event‐related total theta activity were associated with resting theta activity. This specificity of effects may explain why the association between resting state theta activity and overt conflict monitoring performance may not be as strong as often assumed. The results suggest that resting state theta activity is particularly important to consider for input integration processes during cognitive control.

Reconnection‐ and Dipolarization‐Driven Auroral Dawn Storms and Injections

AbstractJupiter displays many distinct auroral structures, among which auroral dawn storms and auroral injections are often observed contemporaneously. However, it is unclear if the contemporaneous nature of the observations is a coincidence or part of an underlying physical connection. We show six clear examples from a recent Hubble Space Telescope campaign (GO‐14634) that each display both auroral dawn storms and auroral injection signatures. We found that these conjugate phenomena could exist during intervals of either relatively low or high auroral activity, as evidenced by the varied levels of total auroral power. In situ observations of the magnetosphere by Juno show a strong magnetic reconnection event inside of 45 Jupiter radii (RJ) on the predawn sector, followed by two dipolarization events within the following 2 hr, coincident with the auroral dawn storm and auroral injection event. We therefore suggest that the auroral dawn storm is the manifestation of magnetic reconnection in the dawnside magnetosphere. The dipolarization region is mapped to the auroral injection, strongly suggesting that this was associated with the auroral injection. Since magnetic reconnection and dipolarization are physically connected, we therefore suggest that the often‐conjugate auroral dawn storm and auroral injection events are also physically connected consequences.

A Bioactive Fraction from Streptomyces sp. Enhances Maize Tolerance against Drought Stress.

Drought stress is threatening the growth and productivity of many economical crops. Therefore, it is necessary to establish innovative and efficient approaches for improving crop growth and productivity. Here we investigated the potentials of the cell-free extract of Actinobacteria (Ac) isolated from a semi-arid habitat (Al-Jouf region, Saudi Arabia) to recover the reduction in maize growth and improve the physiological stress tolerance induced by drought. Three Ac isolates were screened for production of secondary metabolites, antioxidant and antimicrobial activities. The isolate Ac3 revealed the highest levels of flavonoids, antioxidant and antimicrobial activities in addition to having abilities to produce siderophores and phytohormones. Based on seed germination experiment, the selected bioactive fraction of Ac3 cell-free extract (F2.7, containing mainly isoquercetin), increased the growth and photosynthesis rate under drought stress. Moreover, F2.7 application significantly alleviated drought stress-induced increases in H2O2, lipid peroxidation (MDA) and protein oxidation (protein carbonyls). It also increased total antioxidant power and molecular antioxidant levels (total ascorbate, glutathione and tocopherols). F2.7 improved the primary metabolism of stressed maize plants; for example, it increased in several individuals of soluble carbohydrates, organic acids, amino acids, and fatty acids. Interestingly, to reduce stress impact, F2.7 accumulated some compatible solutes including total soluble sugars, sucrose and proline. Hence, this comprehensive assessment recommends the potentials of actinobacterial cell-free extract as an alternative ecofriendly approach to improve crop growth and quality under water deficit conditions.

Optimized Perforation Schemes in Railway Wheels Toward Acoustic Radiation Mitigation

Abstract Rolling noise emitted by railway wheels is a problem that affects human health and limits the expansion of the railway network. It is caused by the wheel vibration due to the wheel-rail contact force, and it is important in almost all the vehicle velocity range. The minimization of noise radiation associated with changes on the wheel web is discussed in this work, focusing on potential shape modifications in existing wheels in the form of a perforation distribution over the web. Such a post-manufacturing technique is a cost-effective solution that can be performed in a relatively short term. The implemented objective function is directly related to the overall radiated sound power, which is minimized using a genetic algorithm-based optimizer. In the acoustic model, radiation efficiencies are approximated to unity, the accuracy of this assumption being also studied in the work. The results reflect that an optimized distribution of perforations on the web of a railway wheel can reduce the total sound power level, by about 5 dB(A) and 2 dB(A) for curved and straight web, respectively. The mitigation of the radiated sound power is due to the fact that certain wheel vibration modes are modified and shifted to other frequencies where they are less excited. Finally, the relevance of the cross-sectional curvature of the web is explored by studying two different web geometries, suggesting that it can strongly influence the noise mitigation effects of the perforation pattern.