bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cockroaches.
Authors: Dhang Partho , Koehler Philip G. , Pereira Roberto M. , Dye II Daniel D. 
Published: May 2022

Abstract

This book chapter discusses cockroaches. Ovoviviparous cockroaches form an egg capsule externally from the body but then withdraw it into a brood sac, females provide water until the eggs hatch, and the nymphs emerge from the female's body. For viviparous cockroaches, the ootheca is withdrawn into the female's body, the eggs develop in the brood sac, and eggs are fed nutrients by the female until the birth of the nymphs. They can cause psychopathology where the thought or sight of cockroaches, or contact with surfaces where cockroaches have been, can affect a person's perception of their own well-being. There are cockroaches that live in temperate and tropical forests, grasslands, salt marshes, aquatic habitats, caves, and deserts. In structures, they have been found feeding on soap, glue and wire insulation, but they usually feed on human food scraps. Cockroach nymphs and adults are primarily scavengers living on feces, decaying leaves and wood, as well as dead animals. Most of these novel developments in reproduction were to protect eggs from parasitoids and predators. The development of the cockroach is hemimetabolous, meaning that there is an egg, nymphal, and adult stage. The eggs of cockroaches are usually deposited in an egg capsule called an ootheca. The German cockroach is the most difficult cockroach to control worldwide due to its resistance to many insecticides. Sanitation and cultural control involve the removal of food, water, and harborage that cockroaches rely on in order to survive. Cockroaches need food, water, and harborage to survive and thrive. As a result, cockroach Integrated Pest Management (IPM) is the best method of protecting people and their properties from cockroaches.
Sporadic pests.
Authors: Dhang Partho , Koehler Philip , Pereira Roberto , Dye II Daniel D. 
Published: May 2022

Abstract

This book chapter discusses sporadic pests. Other insects like thrips, leafhoppers, brown marmorated stink bugs, boxelder bugs and many other beetles that invade structures are huge problems for customers, but very difficult to prevent or control. Sporadic pests are usually insects or other arthropods that people in frequently encounter or that live and breed outside and then enter a building in large numbers. Many times, people are not familiar with these pests and think they may cause significant damage to their structures or endanger them by stinging or biting. The key to solving problems with sporadic pests is to determine the source and cause of the problem. Other sporadic pests originate in decaying organic matter on the ground. Cicada killer wasps, umbrella wasps, and velvet ants are examples of ones that people may encounter in urban areas. Although these sporadic pests may be "minor" pests to the pest management technician, they can be considered a huge problem to the customer. For instance, millipedes have mass migrations from their breeding grounds when weather or soil conditions change.
Cosmic and thermodynamic study of non-canonical scalar field in parameterized modified gravity
Authors: Sultan Abdul Malik , Jawad Abdul 
Published: May 2022

Abstract
Cosmological and thermodynamic implications of non-canonical scalar field are investigated in the cubic gravity by assuming various parameterizations (linear, Chevallier-Polarski-Linder and Jassal-Bagla-Padmanabhan) and recently proposed entropies (Tsallis and Sharma-Mittal). We develop the expressions for Hubble (H) and deceleration (q) parameters in each case and find consistent values with the observational data as H
0 ≃ 67.0, q
0 = − 0.55 ± 0.15. We investigate the perturbed squared speed of sound

(

C

s

2

)

parameter in terms of redshift parameter (z) which leads to the stability for all models. It is also found that the generalized second law of thermodynamics holds for Tsallis as well as for Sharma-Mittal entropies in all the cases of parameterizations.
Kelvin–Helmholtz instability in sheared dusty plasma flows including dust polarization and ion drag forces
Authors: Dolai Bivash , Prajapati Ram Prasad 
Published: May 2022

Abstract
Velocity shear driven Kelvin–Helmholtz (K-H) instability has been investigated in an incompressible subsonic sheared dusty plasma with ion drag and dust polarization forces. A three-component dusty fluid model has been formulated in connection with thermal electrons, inertial ions and charged dust grains. Dispersion relation of K-H instability along with dust-ion two-stream instability has been analyzed for a typical astrophysical dusty plasma environment. The magnitude of the polarization force is found to be small compared to the other forces, although it significantly modifies the K-H modes. The simultaneous presence of ion drag and dust polarization forces excites the K-H instability, which in the absence of these forces, is completely suppressed. It is also observed that the dust polarization interaction parameter and the magnitude of the shear velocity increase the growth rate of the K-H instability. The present results can have significant relevance in understanding the development of velocity shear driven K-H instability in some molecular outflows [1], Saturn’s rings [2] etc.
Mathematical model of convective heat transfer for peristaltic flow of Rabinowitsch fluid in a wavy rectangular duct with entropy generation
Authors: Nadeem Sohail , Qadeer Sabahat , Akhtar Salman , Almutairi Shahah , Fuzhang Wang 
Published: May 2022

Abstract
This research article unfolds a novel mathematical model that interprets the ‘peristaltic flow of Heated Rabinowitsch fluid’ inside a wavy rectangular duct. The fluid flow characteristics are thoroughly examined for Pseudo-plastic in addition to Dilatant nature, (i.e. α > 0 for pseudo-plastic nature and α < 0 for dilatant nature respectively). Peristaltic flow inside a wavy rectangular duct is widely being studied due to immense number of biomedical and engineering applications. We have derived the dimensionless nonlinear partial differential equations in coupled form after applying certain relevant dimensionless quantities, the lubrication technique of low Reynolds number and long wavelength estimations (i.e.,

δ
≪
1

). The dimensionless energy equation is solved by dividing it into two additional equations and after employing suitable procedures, an exact temperature profile solution is computed. The present study has been developed by using hit and trial method to solve the single partial differential equation having two dependent variables in form of extra stress tensors. The solution of temperature profile provides a detailed solution method to exactly solve such complex partial differential equations. For both dilatant and Pseudo-plastic fluids, effective physical parameters are used to depict velocity distribution, pressure gradient and pressure rise, convection and entropy phenomena. When compared with Pseudo-plastic fluid, the Dilatant nature of fluid has a high convection rate. Finally, the phenomenon of entrapment is examined through streamlines that provide a flow visualization inside the wavy sinusoidal duct. Peristaltic pumps are being used for transportation of many fluids like toxic chemicals in nuclear industry, food processing, heart-lung machines, roller and finger pumps and transportation of slurries etc. These usage of these pumps leads to an upgraded mechanical efficiency and lower cost for transportation purposes.
Extracting the low-energy constant

L0r

at three flavors from pion-kaon scattering
Authors: Guruswamy Chaitra Kalmahalli , Meißner Ulf-G , Seng Chien-Yeah 
Published: May 2022

Abstract
Based on our analysis of the contributions from the connected and disconnected contraction diagrams to the pion-kaon scattering amplitude, we provide the first determination of the only free low-energy constant at


(

p

4

)

, known as

L

0

r

, in SU (4∣1) Partially-Quenched Chiral Perturbation theory using the data from the Extended Twisted Mass collaboration,

L

0

r

(
μ
=

M

ρ

)
=
0.77
(
20
)
(
25
)
(
7
)
(
7
)
(
2
)
·

10

−
3

. The theory uncertainties originate from the unphysical scattering length, the physical low-energy constants, the higher-order chiral corrections, the (lattice) meson masses and the pion decay constant, respectively.
Interpretation of XENON1T excess with MeV boosted dark matter *
Authors: Jia Lian-Bao , Li Tong 
Published: May 2022

Abstract
The XENON1T excess of keV electron recoil events may be induced by the scattering of electrons and long-lived particles with an MeV mass and high speed. We consider a tangible model composed of two scalar MeV dark matter (DM) particles,

and

, to interpret the XENON1T keV excess via boosted

. A small mass splitting

is introduced, and the boosted

can be produced using the dark annihilation process of

via a resonant scalar ϕ.

electron scattering is intermediated by a vector boson X. Although the constraints from Big Bang nucleosynthesis, cosmic microwave background (CMB), and low-energy experiments set the

mediated

electron scattering cross section to be

, the MeV scale DM with a resonance enhanced dark annihilation today can still provide sufficient boosted

and induce the XENON1T keV excess. The relic density of

is significantly reduced by the s-wave process

, which is permitted by the constraints from CMB and 21-cm absorption. A very small relic fraction of

is compatible with the stringent bounds on un-boosted

-electron scattering in DM direct detection, and the

-electron scattering is also allowed.
CFD simulation of shockwave-boundary layer interaction induced oscillation in NACA SC2-0714 transonic airfoil
Authors: Zhang Zhi , Hirahara Anna , Xue Yaohua , Uchiyama Naoki 
Published: May 2022

Abstract
To develop an advanced way of designing transonic airfoils for industry, a reliable and user-friendly mesh generator and a robust CFD solver are necessary. Especially, the prediction of unsteady shock buffet phenomenon is always a focus for the CFD simulation of transonic airfoils. In this study, BOXERmesh (an automatic mesh generator) and NEWT (a robust CFD solver), which are developed by CFS (Cambridge Flow Solutions) in collaboration with MHI (Mitsubishi Heavy Industries), are used to perform the CFD simulation of NACA SC2-0714 transonic airfoil. CFD simulation is conducted at two different attack angles with Mach number as 0.74 and Reynold number as 1.5×107 (non-buffet: α=2°; shock buffet: α=3°). A hexahedral dominant mesh is generated by BOXERmesh with the cell number as 5.52 million. Both unsteady RANS (URANS) and LES are performed using the CFD solver NEWT. Specifically, the governing equation is discretized by central differencing scheme with 2nd order accuracy in space by applying Swanson and Turkel type artificial viscosity, and the Adams-Bashford time integration with the dual-time stepping method is applied for temporal discretization in the density-based solver. Results show CFD simulation could reproduce the time averaged chordwise distribution of pressure coefficient at the two conditions. Both URANS and LES successfully capture the unsteady shock buffet phenomenon when increasing attack angle from 2° to 3°. However, the calculated peak oscillation location and the shock buffet frequency are different between URANS and LES. Applying the same mesh resolution, URANS performances better than LES, with the deviation of the shock buffet frequency less than 6% (Exp.: 69 Hz; URANS: 73 Hz). The reason is considered as the wall-normal mesh refinement near the airfoil surface (y+∼66) being not enough for LES to accurately resolve the turbulence scale and capture the boundary layer separation behavior. On the other hand, URANS is thought to be enough to reproduce the periodic moving of the onset of boundary separation and to predict the main characteristics of the shock buffet phenomenon.
Cavitating flow investigation in low specific speed axial flow waterjet pumps
Authors: Wang Zhe , Zhang Ruizhi , Zhou Jiajian , Luo Xianwu 
Published: May 2022

Abstract
In this paper, the cavitating flow in low specific speed axial flow waterjet pumps are treated at different cavitation conditions. In order to analyze the cavitating turbulent flow comprehensively, three axial flow waterjet pumps with the specific speed less than 650 min-1·m3s-1·m are chosen to compare the internal flow phenomenon. The investigations are conducted by numerical simulation, where RANS method is applied with k-ω SST turbulence model and homogeneous cavitation model. The results show that there are several types of cavitation such as tip leakage vortex cavitation, sheet cavitation attached on blade suction surface, and shedding cavity in the pumps. The vortex structure in the low specific speed waterjet pump contains tip leakage vortex, shedding vortex downstream of the sheet cavitation and perpendicular cavitation vortex. It is noted that the cavity firstly occurs at the leading edge near blade tip, and the sheet cavity covering the blade suction surface extends from leading edge to the middle part, while the tip leakage vortex cavitation develops with the decreasing cavitation number. Further analysis using relative vortex transport equation depicts that the vortex stretching term is the main contributor for the vorticity production in the pump, and the vortex dilation and baroclinic torque occur at the interface between cavity and water.
Airfoil optimization using a machine learning-based optimization algorithm
Authors: Song Xueyi , Wang Lin , Luo Xianwu 
Published: May 2022

Abstract
For the design of wind turbines, airfoil optimization is widely required as the operation efficiency of wind turbines is closely dependent on the airfoil aerodynamic performance, where the accuracy of the optimization method is of great importance. In this paper, a machine learning-based optimization algorithm is proposed to improve the airfoil performance. A low-speed airfoil of NACA0012 is selected as the original airfoil for the optimization. The class-shape-transformation (CST) method is used to construct the geometry for the airfoil, and the aerodynamic performance is calculated using the panel code XFOIL. The validation of the simulation is carried out by comparing the predicted aerodynamic performance with the experimental data. In order to improve aerodynamic performance of the airfoil, maximizing the lift-to-drag ratio is selected as the main objective of the optimization problem while maintaining the lift coefficient not smaller than the original values. The results show that the present machine learning-based algorithm has fairly good convergence, and can obtain much higher lift-to-drag ratio for the optimized airfoil compared with the original one. Compared with the traditional genetic algorithm method, the machine learning based method can achieve much better aerodynamic performance and much shorter simulation time for the same airfoil optimization problem. In the future, the machine learning-based method is very promising for fluid machinery design optimization.
Experimental study on fiber suspension in a centrifugal pump by PIV
Authors: Zhang Qihua , Xie Zhiang , Kang Shun , Zhang Weidong 
Published: May 2022

Abstract
To study the influence of fiber particles on the flow field within the passages of an open impeller centrifugal pump, an experiment was performed. The hair fiber was used as solid particle phase in this experiment. After measuring the performance characteristic and PIV data, the flow field in impeller was measured and analyzed. It was shown that at the concentration of 0.1%, a varied distribution of relative velocity from different flow channels was observed. The outlet velocity of the impeller in the second flow channel was obviously higher than that in the first flow channel. The variation of the relative velocity near the hub tended to be consistent at the position of the front plane and the middle plane of the impeller. At 0.2% concentration, the relative velocity at the suction surface of the two channels changes more sharply than the other positions. Within the second channel, it was found that the relative velocity under low flow condition was obviously higher than that under rated and large flow rates. Under different concentrations, the increase of the relative velocity at low flow rate changed intensely compared with the other two conditions. The low velocity zone will be formed near the middle part of the suction surface of the flow channel which gradually decreases with the increase of the flow rate. The external characteristic test shows that the efficiency of the pump and the drag reducing feature increase with the increase of concentration.
Visualization of rotating cavitation in a centrifugal pump
Authors: Yokoi T , Kang D , Nohmi M , Tsuneda T , Okajima J , Iga Y 
Published: May 2022

Abstract
In this study, unsteady cavitation in a centrifugal pump that had 3 blades was visualized in experiments. Cavitation behavior was photographed by using a high-speed camera from the axial direction. To observe rotating cavitation, its aspects were visualized using a high-speed camera. The experiment was performed at rotational speed of 825 rpm with a centrifugal pump under reduced pressure. Rotating cavitation occurred on the suction side of blades under the condition of flow rates lower than the best efficiency point. In addition, observed rotating cavitation was super-synchronous rotating cavitation, which rotates at a faster speed than the impeller in absolute coordinate form. As a result of frequency analysis of the brightness value on the channel, propagation velocity ratios, which is the ratio of the propagation velocity of the cavity to the rotational velocity of the impeller were 1.2 - 1.3. It was confirmed that the propagation velocity ratio of rotating cavitation in the centrifugal pump is close to that of rotating cavitation in the inducer even when the specific speed and Reynolds number are different.
Nonlinear and dissipation effects of pressure waves in water flows containing translational bubbles with a drag force
Authors: Arai S , Kanagawa T , Ayukai T , Yatabe T 
Published: May 2022

Abstract
Weakly nonlinear (i.e., finite but small amplitude) propagation of plane progressive pressure waves in compressible water flows uniformly containing many spherical bubbles is theoretically studied. Drag force acting bubbles and translation of bubbles are newly considered by introducing in momentum conservation equations in a two fluid model and the bubble dynamics equation for volumetric oscillations, respectively. Although these assumptions are the same as our previous paper, in this study, the energy conservation equation for each bubble describing a thermal conduction inside bubble is introduced. By using the method of multiple scales, the Korteweg–de Vries–Burgers equation for low-frequency long wave was derived from the set of basic equations in the two-fluid model. As a result, the dissipation effect was described by two types of terms, i.e., one was the second-order partial derivative owing to the liquid compressibility and the other was the term without differentiation owing to the drag force and the thermal conduction. Finally, we clarified that the dissipation owing to the drag force was smaller than that owing to the thermal conduction.
Flow visualization of non-contacting mechanical seals with bidirectional rotation
Authors: Sato Y , Ochiai M 
Published: May 2022

Abstract
Non-contacting mechanical seals are used as a shaft seal in a turbomachinery. A few micrometers thin lubrication film is formed by grooves on the seals. Various groove shapes were presented, and most of these grooves were designed for unidirectional rotation. However, reverse rotation occurs accidentally in the turbomachinery. In this study, the performance of two type unidirectional grooves was investigated by measuring the pressure in a chamber which means sealed fluid pressure and visualizing the flow in the lubrication film with bidirectional rotation. The measurement results of pressure under forward rotation showed that the pressures fluctuated as rotational speeds increased by hydrodynamic pressure. By contrast, under reverse rotation, the amount of fluctuation was smaller and almost not changed with increasing rotational speeds. In addition, the flow visualization results showed the increase of pressure drop areas and occurrence of gas phase. This indicates the decrease in load capacity and film stiffness. In contrast, the discharging flow from inner to outer side or the breakage of the film were confirmed and prevented fluid leaking. In summary, the results showed the degradation of lubrication characteristics though the no degradation of a sealing performance.
Effect of balanced edge cutting configurations on the aeroacoustics of high-speed turbomachinery
Authors: Song Ji-Hun , Jang Seungsoo , Kim Youn-Jea 
Published: May 2022

Abstract
Flow-noise corresponding to the balanced edge cutting configurations on the compressor wheel of a turbocharger is investigated in this study. The turbocharger is a type of high-speed turbomachinery that rotates at up to 2.0×105 RPM. Microscopic air bubbles are generated inside the compressor wheel due to inaccuracies in the cast introduced in the production process. These bubbles cause a mass-unbalance phenomenon when operated at high rotational speeds, which even leads to breakage in severe cases. To prevent theses problems, cutting configurations are utilized at various locations on the rear of the wheel. However, the cutting shapes rather produce severe vortices from a flow perspective, which has a significant effect on the flow noise. Therefore, after calculating the steady-state shear stress transport k-ω based on the Reynolds-averaged Navier-Stokes equation model, transient large eddy simulation was conducted from initial values using the commercial computational fluid dynamics software, ANSYS FLUENT V20.2. The flow-noise was calculated based on unsteady analysis data with the Ffowcs-Williams and Hawkings equation. The flow-noise of the balanced edge cutting configurations of turbocharger compressor wheels was calculated according to various receiver points, and rotational velocities. Results show that various noise characteristics occur depending on the rotational speeds and the receivers depending on the cutting configurations.
Noise prediction of a box fan by RANS simulation
Authors: Kitamura Masashi , An Byungjin , Nohmi Motohiko 
Published: May 2022

Abstract
The characteristics of aerodynamic performance and aerodynamic noise of a box fan were evaluated to investigate the industrial applicability of computational fluid dynamics (CFD) with Reynolds averaged numerical simulation (RANS) model for fan design. In the case of unsteady RANS, the characteristic of the static pressure rise for flow rates was in good agreement with the experimental results. Aerodynamic noise performance at the design flow rate and low flow rate is well predicted using acoustic/viscous splitting technique based on unsteady RANS with multiple reference frame (MRF). As a result, it was able to evaluate the overall sound characteristic of each fan design relatively. The results suggest that the acoustic/viscous splitting technique based on RANS with MRF simulation has potential as a useful design tool.