bluuebunny/crossref_metadata_2025 huggingface dataset:
The cation and anion bonding modes make a difference: an unprecedented layered structure and a tri(hetero)nuclear moiety in thioantimonates(v)
Authors: Danker Felix , Engesser Tobias A. , Broich Dario , Näther Christian , Bensch Wolfgang
Published: November 2021

Mixing solutions of M2+ (M = Cu2+ or Zn2+) salts containing cyclam as ligand and an aqueous solution of Na3SbS4·9H2O led to crystallization of two new compounds within minutes: {[Cu(cyclam)]3[SbS4]2}n·20nH2O and {[Zn(cyclam)]3[SbS4]2}·8H2O.
Metal complexes bearing photochromic ligands: photocontrol of functions and processes
Authors: Galangau Olivier , Norel Lucie , Rigaut Stéphane
Published: November 2021

Metal complexes associated with photochromic molecules are attractive platforms to achieve smart light-switching materials with advanced properties and to draw exciting perspectives that will boost the field of photoswitchable materials.
Emerging investigator series: moving beyond resilience by considering antifragility in potable water systems
Authors: Goodwill Joseph E. , Ray Patrick , Nock Destenie , Miller Christopher M.
Published: November 2021

By incorporating antifragility, water systems may move beyond resilience and improve performance with extreme events.
Advancement and stabilization of copper(ii) azide by the use of triazole- and tetrazole ligands – enhanced primary explosives
Authors: Wurzenberger Maximilian H. H. , Gruhne Michael S. , Lommel Marcus , Szimhardt Norbert , Stierstorfer Jörg
Published: November 2021

Stabilization of copper(ii) azide by application of various nitrogen-rich azole ligands resulted in a series of powerful energetic coordination compounds with desired properties for primary explosives.
Single-step ball milling synthesis of highly Li+ conductive Li5.3PS4.3ClBr0.7 glass ceramic electrolyte enables low-impedance all-solid-state batteries
Authors: Cronau Marvin , Szabo Marvin , Roling Bernhard
Published: November 2021

Single-step ball milling synthesis of a highly conductive glass ceramic solid electrolyte enables a low-impedance all-solid-state battery.
Aqueous zinc ion batteries based on sodium vanadate electrode materials with long lifespan and high energy density
Authors: Luo Chengkang , Xiao Li , Wu Xiang
Published: November 2021

We have prepared Na7V7.6O20·4H2O (NVO) nanobelts by a facile hydrothermal route. The assembled NVO/Zn batteries deliver a capacity of 309.4 mA h g−1 at 0.3 A g−1 and maintain excellent cycling stability after 10 000 cycles at 10 A g−1.
Artificial interphase engineering to stabilize aqueous zinc metal anodes
Authors: Yan Zichao , Xin Wenli , Zhu Zhiqiang
Published: November 2021

In this mini-review, the state-of-the-art knowledge on the rational artificial interphase engineering of zinc metal anodes for high performance aqueous zinc ion batteries are presented.
Recent advances in the synthesis and applications of phosphoramides
Authors: Zhu Yuan-Yuan , Niu Yuan , Niu Yan-Ning , Yang Shang-Dong
Published: November 2021

The synthesis strategies and applications of phosphinic amides are discussed, including the traditional routes and recent advances in new methodologies.
Dye-sensitized solar cells based on Fe N-heterocyclic carbene photosensitizers with improved rod-like push-pull functionality
Authors: Lindh Linnea , Gordivska Olga , Persson Samuel , Michaels Hannes , Fan Hao , Chábera Pavel , Rosemann Nils W. , Gupta Arvind Kumar , Benesperi Iacopo , Uhlig Jens , Prakash Om , Sheibani Esmaeil , Kjaer Kasper S. , Boschloo Gerrit , Yartsev Arkady , Freitag Marina , Lomoth Reiner , Persson Petter , Wärnmark Kenneth
Published: November 2021

Iron-based photosensitizers for dye-sensitized solar cells with a rod-like push–pull design. Solar cell performance was limited by ultrafast (sub-ps) recombination, but yielded better performance than the homoleptic parent photosensitizer.
Effects of Age and Uncertainty on the Visual Speech Benefit in Noise
Authors: Beadle Julie , Kim Jeesun , Davis Chris
Published: November 2021

Purpose:

Listeners understand significantly more speech in noise when the talker's face can be seen (visual speech) in comparison to an auditory-only baseline (a visual speech benefit). This study investigated whether the visual speech benefit is reduced when the correspondence between auditory and visual speech is uncertain and whether any reduction is affected by listener age (older vs. younger) and how severe the auditory signal is masked.

Method:

Older and younger adults completed a speech recognition in noise task that included an auditory-only condition and four auditory–visual (AV) conditions in which one, two, four, or six silent talking face videos were presented. One face always matched the auditory signal; the other face(s) did not. Auditory speech was presented in noise at −6 and −1 dB signal-to-noise ratio (SNR).

Results:

When the SNR was −6 dB, for both age groups, the standard-sized visual speech benefit reduced as more talking faces were presented. When the SNR was −1 dB, younger adults received the standard-sized visual speech benefit even when two talking faces were presented, whereas older adults did not.

Conclusions:

The size of the visual speech benefit obtained by older adults was always smaller when AV correspondence was uncertain; this was not the case for younger adults. Difficulty establishing AV correspondence may be a factor that limits older adults' speech recognition in noisy AV environments.

Supplemental Material

https://doi.org/10.23641/asha.16879549
Verbal Working Memory Error Patterns and Speech-Language Outcomes in Youth With Cochlear Implants
Authors: Romano Daniel R. , Kronenberger William G. , Henning Shirley C. , Montgomery Caitlin J. , Ditmars Allison M. , Johnson Courtney A. , Bozell Hannah D. , Yates Adeline D. , Pisoni David B.
Published: November 2021

Purpose:

Verbal working memory (VWM) delays are commonly found in prelingually deaf youth with cochlear implants (CIs), albeit with considerable interindividual variability. However, little is known about the neurocognitive information-processing mechanisms underlying these delays and how these mechanisms relate to spoken language outcomes. The goal of this study was to use error analysis of the letter–number sequencing (LNS) task to test the hypothesis that VWM delays in CI users are due, in part, to fragile, underspecified phonological representations in short-term memory.

Method:

Fifty-one CI users aged 7–22 years and 53 normal hearing (NH) peers completed a battery of speech, language, and neurocognitive tests. LNS raw scores and error profiles were compared between samples, and a hierarchical regression model was used to test for associations with measures of speech, language, and hearing.

Results:

Youth with CIs scored lower on the LNS test than NH peers and committed a significantly higher number of errors involving phonological confusions (recalling an incorrect letter/digit in place of a phonologically similar one). More phonological errors were associated with poorer performance on measures of nonword repetition and following spoken directions but not with hearing quality.

Conclusions:

Study findings support the hypothesis that poorer VWM in deaf children with CIs is due, in part, to fragile, underspecified phonological representations in short-term/working memory, which underlie spoken language delays. Programs aimed at strengthening phonological representations may improve VWM and spoken language outcomes in CI users.
Optimization with learning-informed differential equation constraints and its applications
Authors: Dong Guozhi , Hintermüller Michael , Papafitsoros Kostas
Published: November 2021

Inspired by applications in optimal control of semilinear elliptic partial differential equations and physics-integrated imaging, differential equation constrained optimization problems with constituents that are only accessible through data-driven techniques are studied. A particular focus is on the analysis and on numerical methods for problems with machine-learned components. For a rather general context, an error analysis is provided, and particular properties resulting from artificial neural network based approximations are addressed. Moreover, for each of the two inspiring applications analytical details are presented and numerical results are provided.
An image analysis method for determining boiling front in minichannel heat exchanger
Authors: Rafałko Gabriela , Grzybowski Hubert , Dzienis Paweł , Mosdorf Romuald
Published: November 2021

In this work a numerical method for determining boiling front in short time period of flow was presented. A non-stationary boiling in rectangular eleven minichannels (0.25 mm x 0.25 mm x 32 mm) was recorded using Phantom v1610 high speed camera with the speed of 6000 fps. In the algorithm correlation between subsequent frames was computed. Frames were divided into reference and test frames. In each iteration a part of a reference frame called ‘reference gate’ and moving part of a test frame called ‘moving gate’ were considered. A two-dimensional correlation coefficient was calculated. Such method allowed to identify the location of boiling front in each minichannel separately.
Optimisation of microfluidic polymerase chain reaction devices
Authors: Zagklavara Foteini , Jimack Peter K. , Kapur Nikil , Querin Osvaldo M. , Thompson Harvey M.
Published: November 2021

The invention and development of Polymerase Chain Reaction (PCR) technology have revolutionised molecular biology and molecular diagnostics. There is an urgent need to optimise the performance of these devices while reducing the total construction and operation costs. This study proposes a CFD-enabled optimisation methodology for continuous flow (CF) PCR devices with serpentine-channel structure, which enables the optimisation of DNA amplification efficiency and pressure drop to be explored while varying the width (W) and height (H) of the microfluidic (μ) channel. This is achieved by using a surrogate-enabled optimisation approach accounting for the geometrical features of a μCFPCR device by performing a series of simulations using COMSOL Multiphysics 5.4®. The values of the objectives are extracted from the CFD solutions, and the response surfaces are created using polyharmonic splines. Genetic algorithms are then used to locate the optimum design parameters. The results indicate that there is the possibility of improving the DNA concentration and the pressure drop in a PCR cycle by ~2.1 % ([W, H] = [400 μm, 50 μm]) and ~95.2 % ([W, H] = [400 μm, 80 μm]) respectively, by modifying its geometry.
Comparison of Two-Phase Porosity Models for High Capacity Random Packing
Authors: Poulsen Mathias , Sørensen Kim , Condra Thomas
Published: November 2021

High capacity random packing is used in absorption applications where a large throughput of gas is required while simultaneously maintaining as low a pressure loss as possible. Utilising computational fluid dynamics to capture the internal flow patterns and transients when designing packed bed towers can be advantageous in respect to expected performance and cost optimisation. However, capturing the direct interaction between gas, liquid and packing is not computationally feasible and therefore the packed bed is modelled as a porous media. In this work four different porosity model are calibrated with idealised equations to data for the high capacity packing IMTP or I-Ring. The different models are evaluated based on their ability to predict pressure loss and liquid holdup in the packed bed. An Eulerian two-phase model with a porous zone representing the packed bed is setup in a cylindrical tower. The CFD results are compared to the predictions of the best performing porosity model. It was found that the best performing model had an absolute mean error of 6.7% when calibrated with the idealised equations. This error increased to 10.5% when the porosity model was implemented into the CFD model.
Experimental study on the evaporating progress of hexane lens on immiscible liquid：Spreading and receding
Authors: Chen Aiqiang , Yin Jinghong , Wang Huiqin , Liu Bin , Bennacer Rachid
Published: November 2021

The change of evaporation liquid on another immiscible liquid has important guiding significance for many applications. In this experiment, the geometric temperature distribution and evaporation rate of n-hexane droplets were observed and recorded by changing the temperature of deionized water. The results show that with the increase of temperature of deionized water-based solution, the maximum diameter of n-hexane droplet spreading after titration increases gradually, while the minimum diameter of n-hexane droplet disappearing decreases gradually. Meanwhile, the evaporation rate of n-hexane droplet is constant during the whole evaporation process. It should also be mentioned that if the base solution is changed from deionized water to a certain concentration of salt solution, the maximum diameter of n-hexane droplet spreading will be reduced, and the evaporation intensity will be relatively reduced. These experimental results will give us a better understanding of the mechanism and characteristics of droplet evaporation.
Determining of reservoir fluids properties using PVTP simulation software- a case study of buzurgan oilfield
Authors: Abdulrazzaq Tuqa , Togun Hussein , Haider Dalia , Ali Mariam , Hamadi Saja
Published: November 2021

The measurement of oil reservoirs and their performance with hydrocarbon reservoirs is used to distinguish the properties of reservoir fluids, which is significant in various reservoir studies. As a result, in the various oil industries, adopting the appropriate methods to obtain accurate property values is very important. The current paper is about a case study of the BUZURGAN Oilfield and how the PVTp software was used to predict phase activity and physical properties. To understand the properties of fluids for the reservoir and phase behavior, the black oil model and the equation of state (EoS) model are used. (Glaso) correlation is used to calculate the bubble point strain, solubility, and formation volume factor. The Beal's correlation was also used to measure viscosity, while the equation of state (EoS) model was used to determine phase behavior and density. Furthermore, the properties of PVT were discovered using the software, and the results were compared to laboratory analysis of PVT, with suitable models being displayed. According to the findings, the used model has the highest saturation pressure, which was chosen for use in reservoir management processes and the preparation of a geological model to reflect the field later. It is clear that the program is appropriate due to the accurate dependence of PVT measurements on laboratory tests in the case that tests are required during the reservoir's productive existence.
Entropy generation of a hybrid nanofluid on MHD mixed convection is a lid-driven cavity with partial heating having two rounded corners
Authors: Korei Zakaria , Benissaad Smail
Published: November 2021

This research aims to investigate thermal and flow behaviors and entropy generation of magnetohydrodynamic Al2O3-Cu/water hybrid nanofluid in a lid-driven cavity having two rounded corners. A solver based on C ++ object-oriented language was developed where the finite volume was used. Parameter’s analysis is provided by varying Reynolds numbers (Re), Hartmann numbers (Ha), the volume fraction of hybrid nanofluid (ϕ), radii of the rounded corners. The findings show that reducing the radii of the rounded corners minimizes the irreversibility. Furthermore, the thermal conductivity and dynamic viscosity of hybrid nanofluid contribute to increasing the irreversibility. Finally, the entropy generation is decreased by increasing the Hartman number and increases by rising the Reynolds number.
Effect of porous partition height on thermal performance of a ventilated cavity using LBMMRT
Authors: Hireche Zouhira , Himrane Nabil , Nasseri Lyes , Ameziani Djamel Eddine
Published: November 2021

The objective of this work is to study the effect of the thickness of a porous separation on the thermal performance in a cavity with displacement ventilation. The cold air jet enters and exits through two openings located in the lower and upper parts of the left wall and the right wall respectively. The other horizontal walls are also adiabatic. The hydrodynamic and thermal characteristics of the transfer were studied for three configurations with the same aspect ratio L/H=2. The height Hp of the porous separation was varied between 0.2 and 0.8 where is placed in the center of the cavity. The transfer rates on the active wall for the thicknesses were studied for different permeability therefore different Darcy numbers varying over an interval:10-6≤Da≤10. The dimensionless Rayleigh and Reynolds numbers were taken from the rows: 10≤Ra≤106 and 50≤Re≤500. The governing equations of momentum and energy were solved by the Lettice Boltzmann Multiple Relaxation Time Method (LB-MRT) D2Q9 for the velocity field and D2Q5 for the temperature field. In order to take into account the introduction of the porous medium, an additional term is added to the standard LB equations based on the generalized model (Darcy model extended to Brinkman-Forchheimer).
Influence of Density and Water Content on The Thermal Diffusivity of Wood Chips
Authors: Zine Oussama , El bouardi Abdelmajid , Taoukil Driss , Kadri El-Hadj , El abbassi Ikram
Published: November 2021

The use of agro-industrial residues are currently experiencing an undeniable revival of interest in developing fully renewable insulation materials, that can be competitive in price and performance, in addition of low embodied energy. Among these vegetable waste materials; wood chips. These latter are light, compressible and very sensitive to water, due to their highly porous structure, which constantly modifies their thermal properties. The main objective of this study is to examine the influence of moisture content and density on the thermal diffusivity of wood chips, using the flash method. Four theoretical models were used to identify the thermal diffusivity. The results obtained show a decrease in thermal diffusivity with an increase in wood chips density. Furthermore, moisture content has an influence on thermal diffusivity. The experimental results show fluctuations with a slight decrease in thermal diffusivity with a maximum corresponding to a moisture content value Wm.
Evaluation of a Jet-Pump for the Improvement of Oil-Water Flow in Pipeline Loops Using CFD Tools
Authors: Asuaje Miguel , Toteff Jens , Noguera Ricardo
Published: November 2021

Despite their low efficiency compared with centrifugal pumps, jet pumps are highly reliable, robust equipment with modest maintenance, ideal for many applications, mainly in the oil & gas industry. Jet pumps are conventionally used to draw fluid from a storage tank in the petrochemical industry or as an artificial lift system to produce oil from a reservoir using energy from the primary fluid. The trunk lines in oil production systems can experience an unfavourable phenomenon due to the fluid's low velocities. In the case of transporting a heavy oil-water mixture with low flow velocities, it could promote oil and water stratification. Due to high viscosity, the stratified oil stick on the pipe,| causing a diameter reduction, resulting in a drop in fluids production and increased energy consumption. Given the virtue of jet pumps, this paper proposes using this equipment as an oil-water transfer pump as an alternative to expensive conventional multiphase pump systems. The jet pump will add fluid into the line, increase the fluid velocities, and promote the homogenous mixture of oil and water. Using ANSYS CFX, the effect of installing a jet pump in a conventional trunkline loop was analysed. Three jet pump configurations were simulated for different driving fluid pressures and compared against a traditional pipeline loop's performance. The first configuration shows a poor performance increasing only until 10% of handling fluids. Conversely, with the improved jet pump configurations rise of the fluid production by 30% has been obtained.
On the mathematical model simplification using constant Lewis number – Impact assessment on heterogeneous char conversion process
Authors: Asheruddin N Mohammed , Shivapuji Anand M , Srinivasaiah Dasappa
Published: November 2021

Reactive systems in a thermochemical conversion domain are modelled considering N-specie, 1-energy and 2-mass conservation equations assuming negligible pressure gradient resulting in N+3 non-linear coupled PDE system with dependency on thermodynamic and transport properties. Typically, simplistic temperature-dependent polynomials are chosen for estimating thermal conductivity and specific heat, however, the estimation of mass diffusion coefficient (Di;mix) follows a complicated procedure involving kinetic theory culminating in Chapman-Enskog equation. This renders the solution computationally intensive. The complexity is simplified by assuming a constant Lewis (Le) number, a standard practice in the analytical solution for conventional reactive systems. In fixing Le, (Di;mix) is equated to thermal diffusivity (a ratio of thermodynamic properties) resulting in the specie and energy equation yielding a similar solution and collapse of N+3 system of simultaneous equations to 3 equations. The current article explores the validity and limitation of assuming constant Le in the simulation of char conversion process in air and steam. Results of char conversion are compared for fixed Le and D estimated with Chapman{Enskog expresion. The analysis suggests that Le remains invariant only under a severely restricted set of conditions. Fixing Le influences, the conversion process either over-/under-predicting the conversion time scales and the product gas composition.
Modelling of the cylindrical geometry cooling process based on the solution of the inverse problem
Authors: Joachimiak Magda , Joachimiak Damian
Published: November 2021

Processes of thermo-chemical treatment, such as nitriding, are used to create a surface layer of high mechanical values. When the nitriding process, often consisting of a multi-stage heating and soaking, is ended, elements being under treatment are cooled. The cooling rate depends on the massiveness and geometry of the given element. Too fast cooling can result in the formation of high temperature gradients, which leads to the element damage. This paper presents numerical analysis of a cylinder cooling. The non-linear, unsteady inverse problem for the heat equation was solved. Test examples were chosen based on experimental research conducted in the furnace for thermo-chemical treatment.
Coupling of differential CFD and integral human thermophysiology numerical models applied in indoor ventilated spaces
Authors: Conceição Eusébio , Gomes João , Lúcio M. Manuela , Conceição M. Inês , Ramos André , Awbi Hazim
Published: November 2021

This work presents the development of the coupling of differential Computer Fluid Dynamics and integral human thermo-physiology numerical models applied in indoor ventilated spaces. The study is performed in a virtual chamber, similar to an existing experimental chamber, with dimensions of 4.50×2.55×2.50 m3. The chamber, occupied with twelve virtual manikins, is equipped with six tables, twelve chairs, one exhaust system and one inlet system, based on confluents jets system. In the exhaust system, they are considered six air ducts, located above the head level, connected to the ceiling area. The inlet system, based in four vertical ducts, with 0.15 m diameter, located on the corners of the chamber, is equipped with consecutive holes, that promotes horizontal jets near the wall. The results demonstrate that when the airflow rate increases the air quality number increases, the thermal comfort number decreases, and the Air Diffusion Index increases slightly. The predicted percentage of dissatisfied index values show that the thermal comfort level of occupants is acceptable, the dioxide carbon concentration values show that the indoor air quality is near the acceptable value and the Draught Risk is acceptable.
Design and simulation of point absorber wave energy converter
Authors: Singh Devesh , Singh Anoop , Ranjan Paul Akshoy , Samad Abdus
Published: November 2021

The paper aims to design and simulation of a wave energy harvesting system commonly known as point absorber for Ennore port located in the coastal area of Chennai, India. The geographical condition of India, which is surrounded by the three sides with seas and ocean, has enormous opportunity for power production through wave energy harvesting system. The wave energy converter device is a two-body floating system and its both parts are connected by power take-off unit which acts as spring mass damper system. In this paper, the hydrodynamic diffraction, stability analysis, frequency, and time response analysis is carried out on ansys-aqwa. The numerical results are compared with the results obtained from the similar experiments for validation of CFD solver. Effects of the properties featuring wave characteristics including wave height and wave period of Ennore port on the energy conversion, Froude-Krylov and diffraction force, response amplitude operator (RAO) are studied. Based on the study, float diameter, draft, geometry, and varying damping coefficient for power generation are optimized. Finally, the optimally designed point absorber is simulated as per Indian ocean energy harvesting standard and mass of the system, heave dimension, diffraction forces, and pressure variations are computed.
Application of passengers’ thermoregulation integral model used in the evaluation of thermal comfort in vehicles compartment equipped with internal curtains
Authors: Conceição Eusébio , Gomes João , Lúcio M. Manuela , Conceição M. Inês , Ramos André , Awbi Hazim
Published: November 2021

This work evaluates the passengers thermal comfort level inside a vehicles compartment. The numerical study, made in winter conditions, consider a bus indoor environment equipped with internal curtains, internal seats, lateral panels, ceiling, floor and occupied by 52 passengers. The numerical model considers the passengers and vehicle grid generation, passengers body and clothing thermal response and passengers thermal comfort level. The grid generation is used to evaluate the view factors and Mean Radiant Temperature that the passengers are subjected. In this calculus the passengers and the vehicles surfaces shading devices are considered. The thermal response numerical models consider the energy and mass balance integral equations. The thermal comfort evaluation considers the heat produced inside the body and the heat exchange between the body and the environment. The human body numerical model considers also the thermoregulatory system to control the temperature. The numerical model is used to evaluate the thermal comfort level that seated passengers are subjected in a bus equipped with asymmetrical warm curtains. Three Cases studies were developed: the first one considers the temperature curtains equal to the indoor bus surfaces, while the other two consider higher temperatures values. All Cases are thermally comfortable according to the standards.
Study of A Thermal Energy Storage System Using the Lattice Boltzmann Method
Authors: El Mhamdi Oussama , Addakiri Soumia , Semma ElAlami , El Alami Mustapha
Published: November 2021

Thermal energy storage (TES) systems are much preferred in many engineering applications, which have the ability to overcome the mismatch between energy supply and energy demand. TES can be used to store thermo-chemical, sensible, or latent heat or a combination of these. Among the three forms, latent heat thermal energy storage (LHTES) has grown considerably in importance over recent years as a promising alternative to traditional systems. These systems use phase change materials (PCM), in simple or cascade configuration, and store the latent heat of melting (charging process) and release it during solidification (discharging process).

Among different configurations of LHTES systems, tube and shell heat exchangers represent a promising and simple design in high temperature PCM. In this paper, we present a new numerical study involving a tube and shell heat exchanger to evaluate the heat storage phenomena. A case study and numerical results are provided using the Lattice Boltzmann Method.
High Order Accurate Numerical Simulation of Vortex-Induced Vibrations of a Cooled Circular Cylinder Case using Solution Dependent Weighted Least Square Gradient Calculations
Authors: Sonawane Chandrakant , Praharaj Priyambada , Pandey Anand , Kulkarni Atul
Published: November 2021

In this paper, the fluid-structure interaction problem: vortex-induced vibration of a cooled circular cylinder involving thermal buoyancy is numerically investigated. The elastically mounted cylinder having a temperature lower than the flowing fluid is modelled using mass-spring-damper hence allowed to vibrate in the transverse direction to the flow direction. The gravity is acting opposite to the flow direction. In-house fluid-structure interaction solver is developed based on Harten Lax and van Leer with contact for artificial compressibility Riemann solver. The arbitrarily Lagrangian-Eulerian formulation is employed here, and the mesh is dynamically moved using radial basis function-based interpolation. The solution-dependent weighted least squares based gradient calculations are developed to achieve higher-order accuracy over unstructured meshes. The laminar incompressible flow at Reynolds number, Re = 200, and Prandtl number, Pr = 0.71, is simulated for the mass ratio of 1 and reduced damping coefficient of 0.001. The flow is investigated for Richardson number (-1, 0) and over a wide range of natural frequencies of the cylinder. The heat transfer characteristics from a cylinder are captured and compared with the existing literature results. From the study, it can be observed that in the presence of the thermal boundary layer, the oscillation of the cylinder increases to its maximum amplitude, particularly for values of natural frequencies (0.063 – 0.3).
Numerical analysis of forced convection heat transfer in a rectangular micro-channel totally filled with Ag/ water nano fluid in slip flow regime using the lattice Boltzmann method
Authors: Ben Ltaifa Kaouther , D’Orazio Annunziata , Karimipour Arash , Dhahri Hacen
Published: November 2021

Numerical simulation reported on heat transfer and fluid flow in a two-dimensional rectangular micro channel totally filled with Ag/water. The first –order slip/jump boundary conditions were uniformly imposed to the up and bottom walls. The governing conservation equations are translated in dimensionless form using the thermal Single Relaxation Time (T-SRT) modified Lattice Boltzmann Method (LBM) with double distribution functions (DDFs). The viscous dissipations effects are adopted into the energy equation. Effects of nanoparticle volume fraction φ, slip coefficient, B, on the flow of Nano fluid and heat transfer were studied. The results were interpreter in terms of slip velocity; temperature jump and Nusselt number. Based on the results found, it can be concluded that decreasing the values of slip coefficient enhances the convective heat transfer coefficient and consequently the Nusselt number (Nu) but increases the slip velocity at the wall and temperature jump values.
Computational investigation on heat transfer augmentation of a circular tube with novel hybrid ribs
Authors: Bhattacharyya Suvanjan , Vishwakarma Devendra Kumar , Roy Sanghati , Dey Kunal , Benim Ali Cemal , Bennacer Rachid , Paul Akshoy Ranjan , Huan Z.
Published: November 2021

Present study reports a computational investigation on heat transfer and pressure drop characteristics for flow through a heat exchanger tube fitted with novel hybrid ribs by using magnetic nanofluid (Fe3O4). Effects of different rib geometry on heat transfer and pressure drop characteristics have been investigated for Reynolds number ranging from 3 000 to 22 000. Until now, there is little information available in the literature on the method of quantifying the effect of forced convection on the heat transfer and pressure drop of hybrid rib (HR) inserts by using magnetic nanofluid (MNF). The transition SST models along with governing equations (continuity, momentum, and energy equations) are numerically solved with ANSYS Fluent 19.2. The simulation results are validated with established correlations and excellent agreement was found. Heat transfer coefficient is more in combined arrangement (HR and MNF) compared to acting alone arrangement (only MNF).
3D Numerical simulation of turbulent heat transfer and Fe3O4/nanofluid annular flow in sudden enlargement
Authors: Togun Hussein
Published: November 2021

In this paper, 3D Simulation of turbulent Fe3O4/Nanofluid annular flow and heat transfer in sudden expansion are presented. k-ε turbulence standard model and FVM are applied with Reynolds number different from 20000 to 50000, enlargement ratio (ER) varied 1.25, 1.67, and 2, , and volume concentration of Fe3O4/Nanofluid ranging from 0 to 2% at constant heat flux of 4000 W/m2. The main significant effect on surface Nusselt number found by increases in volume concentration of Fe3O4/Nanofluid for all cases because of nanoparticles heat transport in normal fluid as produced increases in convection heat transfer. Also the results showed that suddenly increment in Nusselt number happened after the abrupt enlargement and reach to maximum value then reduction to the exit passage flow due to recirculation flow as created. Moreover the size of recirculation region enlarged with the rise in enlargement ratio and Reynolds number. Increase of volume Fe3O4/nanofluid enhances the Nusselt number due to nanoparticles heat transport in base fluid which raises the convection heat transfer. Increase of Reynolds number was observed with increased Nusselt number and maximum thermal performance was found with enlargement ratio of (ER=2) and 2% of volume concentration of Fe3O4/nanofluid. Further increases in Reynolds number and enlargement ratio found lead to reductions in static pressure.
Length-weight relationship and condition factor of Hamilton's thryssa fish (Thryssa hamiltonii) from Pabean Bay, West Java, Indonesia
Authors: Sunaryo Ade
Published: November 2021

The length-weight and condition factor can be used as an indicator of the condition for fish growth and to determine the suitability of the environment. The research objective was to evaluate the relationship between length-weight and condition factor of Hamilton's thryssa fish (Thryssa hamiltonii) from Pabean Bay West Java Indonesia. The researchers have been carried out to analyze the two essential parameters: the lengthweight relationship that can be used to evaluate and investigate stock density and condition factor of Hamilton's thryssa fish (Thryssa hamiltonii). A total of 195 fish samples were collected over the 8th month from the sea estuary and measured and weighed during a field survey conducted from April to December 2015. Samples of fish were collected using gillnet and set net. The total length of the fish ranged from 47-186 mm, with body weights ranging from 0.47 - 45.37 g. The results of the length-weight relationship were shown as regression was Y = 7E-07 X3.4339 or W = 7.45 x 10−7.L3.43389, and the condition factors ranged from 0.77 to 1.39. These research results indicated that the growth pattern of Hamilton's Thryssa fish (Thryssa hamiltonii) was positive allometric.
The metal concentrations in several fish species on the coast of Muara Gembong, Bekasi Regency, West Java, Indonesia
Authors: Nastiti Adriani S. , Hediato Dimas A. , Putri Masayu R. A. , Krismono
Published: November 2021

Muara Gembong Beach is part of the eastern area of Jakarta Bay which is still a source of fish consumption for the local community. This study aims to present information about the concentration of metals in several types of fish. The study was conducted in October 2018 at 5 stations, namely the Citarum River, Muara Bendera, Pulau Buaya, Muara Blacan, and Muara Jaya. The parameters measured were copper (Cu), cadmium (Cd), Chromium (Cr), lead (Pb), Zinc (Zn), mercury (Hg), and Arsen (As) in several types of fish consumption sizes, with the local names Kuro (Eleutheronema tetradactylum), Keropak (Hexanematichthys sagor), Bloso (Glossogobius giuris), Samgeh (Nibea soldado), Shrimp (Macrobrachium rosenbergii), Mujair (Oreochromis mossambicus), Patin (Pangasianodon hypophthalmus), and detected in fish samples. Zn was detected in all fish samples and research stations, while Cu was detected in shrimp in Muara Blacan and Muara Flag. As detected in Kuro in Muara Jaya, Mujair in Muara Blacan, Shrimp in Muara Bendera. The concentration of Zn, As, and Cu has exceeded the quality standard in biota. Prevention of the entry of waste containing metals into waters, among others, through increasing public regulations and strict sanctions from the government.
Heavy metals content (Hg, Cd, Pb, and Cu) in streaked spinefoot Siganus javus (Linnaeus, 1766) in Bojonegara Waters, Banten Bay, Indonesia
Authors: Tresanayaputri Cok Istri Agung Apriliyanti , Batu Djamar T. F. Lumban , Sulistiono
Published: November 2021

Anthropogenic activities contribute to heavy metals so that their concentration in the waters increases and causes accumulation, especially in streaked spinefoot. This study aims to estimate the level accumulation of (Hg, Cd, Pb, and Cu) heavy metals contained in streaked spinefoot (Siganus javus) meat in Bojonegara waters, Banten Bay, Indonesia. A sampling of 30 to 50 grams of fish meat is carried out every month from August to October 2020 and heavy metals analysis in streaked spinefoot meat was carried out in February 2021 using atomic absorption spectrophotometry (AAS). The (Hg, Cd, and Pb) heavy metals contained in the streaked spinefoot meat were undetected by the AAS, while the content of heavy metal Cu on small fish is 0.348 to 1.530 mg kg-1, and large fish is less than 0.015 mg kg-1 to 5.390 mg kg-1. Bioaccumulation Cu metal in small and large streaked spinefoot included low to high accumulation, while it was low for other types of metal. The safe limit for consumption of streaked spinefoot meat for adults (50 kg) is 32.468 kg of meat/week, while for children (15 kg), it is 9.740 kg of meat/week.
Biochemical composition of tropical eel Anguilla bicolor McClelland,1844 in Freshwater and Estuary
Authors: Rachmawati Farida Nur , Susilo Untung
Published: November 2021

During migration, Anguilla bicolor will stop its feeding activity and use energy from its body lipid stores. Therefore, information on changes in the body lipid content of eels is essential to know the preparation of spawning migration. Thus, it is interesting to study the body composition of A. bicolor in freshwater and estuaries. This research conducted a survey method. The eel was obtained from the Serayu River (freshwaters) and Segara Anakan (Estuary). The observed variables were water, dry weight, lipid, protein, crude fiber, ash, and BETN of eel. Oneway ANOVA analyzed data. The results show that freshwater eels' average body length and weight were 457.875 cm ± 153.8552 and 224.4375 g ± 165.3735. The body length and weight of the estuary eels were smaller than freshwater eels, which are 372.5714 cm ± 152.6467 and 109.6429 g ± 134.6054, respectively. The body composition of eel, except for lipid content, was similar for both habitats (p>0.05). However, the body lipid content of freshwater eels and the estuarine eel differed (p<0.05), namely 40.15% ± 9.63 and 27.33% ± 9.93, respectively. In conclusion, the lipid body content of freshwater eels was higher than the estuary eel, while another is relatively the same.
Population parameters of the yellow-edged lyretail (Variola louti, Forsskål, 1775) in Sibolga Waters
Authors: Hargiyatno Ignatius Tri , Faizahl Ria
Published: November 2021

The grouper is one of the coral fishery commodities with high economic value. One of the members of the Serranidae family is the yellow-edged lyretail (Variola louti). In Sibolga waters, this fish was caught by traps and handline. The exploitation of yellow-edged lyretail in Sibolga waters was carried out continuously. Therefore, it was necessary to take good management measures to maintain the sustainability of this fish. This study was conducted in Sibolga from April-December 2016. This study aims to get information about population parameters, size distribution, and growth patterns of the fish in Sibolga waters. The size distribution of the yellow-edged lyretail caught was 24-41 cm, with an average length of 31.57 cm. The weight of the yellow-edged lyretail caught ranged from 200-680 g. The mean weight was 395.53 g. The growth pattern of the yellow-edged lyretail is negative allometric. The growth equation for a yellow-edged lyretail was Lt = 48.55 (1 – e-0.1 (t-0.7806)). The value of length at first captured (Lc) = 31,99 cm. Natural mortality (M) = 0.42/year, fishing mortality (F) = 0.50/year. The exploitation rate = 0.55/year, it means the exploitation rate of the yellow-edged lyretail in Sibolga waters slightly exceeds the optimum
Length-weight relationship and condition factor of tropical sand goby, Acentrogobius caninus (Valenciennes 1837) from Pabean Bay, West Java, Indonesia
Authors: Syafei Lenny S.
Published: November 2021

This study aims to determine the length-weight relationship (LWR) and evaluate the condition factors of the tropical sand goby, Acentrogobius caninus (Valenciennes 1837), in Pabean Bay West Java, Indonesia. The sampling was carried out once a month from January to December 2015, and during that period, 152 samples were collected. The LWR is W = 9 x 10-6 L-3.0356. The growth pattern of tropical sand goby is isometric (b=3). The monthly relative condition factor ranged from 0.798 to 1.322 (average: 1.028).
Heavy metal contents of Hg, Cd, Pb, and Cu in splendid ponyfish Eubleekeria splendens (Cuvier, 1829) meat in Banten Bay, Indonesia
Authors: Sagala Lisbet , Sulistiono  , Batu Djamar T.F.L.
Published: November 2021

Banten Bay is an area affected by industrial, shipping, and domestic activities. These have the potential to produce wastes in the form of heavy metals and can accumulate in the body of aquatic organisms such as the splendid ponyfish Eubleekeria splendens (Cuvier, 1829). This study aimed to determine the accumulation of heavy metals Hg, Cd, Pb, and Cu in splendid ponyfish Eubleekeria splendens (Cuvier, 1829) meat in Banten Bay, Serang Regency, Banten Province. Sampling was carried out for three months, from August to October 2020. Analysis of heavy metal content was carried out using AAS (Atomic Absorption Spectrophotometer). The content of heavy metals Hg, Cd, Pb, and Cu in splendid ponyfish meat were <0.030 mg/kg, <0.001 mg/kg, <0.005 mg/kg, and 0.224-0.437 mg/kg. Bioaccumulation of heavy metals Hg, Cd, Pb, and Cu in small and big splendid ponyfish meat has a low accumulation rate. During the observation period, the heavy metal content of Hg, Cd, Pb, and Cu in small and big splendid ponyfish meat was not significantly different.
Analysis of the economic impact of covid-19 on local community income on Natsepa Beach ecotourism in Central Maluku Regency
Authors: Papilaya Renoldy L. , Lessil Costansa G.
Published: November 2021

Natsepa Beach has a natural beauty that attracts tourist arrivals and is managed by the Central Maluku Regency Government. The existence of covid-19 has a significant impact on local people’s income and local labor. The purpose of this study is to descriptively compare the presence of Covid-19 to the village of the business in the Natsepa beach. The research method used is the survey method, and the sampling method used is nonprobability sampling. The results showed that the average number and quality of tourism services significantly declined inside and outside the location. During the pandemic covid, the revenue of the business unit/month in the Natsepa beach decreased from IDR.1920000 to IDR.725500; business unit outside the Natsepa Beach tourist attraction from IDR.1850105 to IDR.826725 and the community around the Natsepafrom IDR.1830698 to IDR.1278540,-. The economic impact value at the usual time (2018) compared to 2020 was obtained from KIM, namely from 2.04 to 0.84; the importance of RIM I, 1.59 to 1.33, and RIM II 2.31 to 1,73. The conclusion of this study shows that local communities have experienced a drastic decline in income so that they need to be supported by the government.
Fish Identification based on Partial Fragments of The Mitochondrial COI Subunit I Gene
Authors: Wulandari Tuah N. M.
Published: November 2021

The mtDNA sequences revealed that several of the fish studied were Hampala macrolepidota and Barbonymus gonionotus. The objective of this research was to learn the pattern of COI gene in mtDNA and establish a phylogenetic tree. Basic Local Alignment Search Tool-nucleotide (BLASTn) confirmed that Barbonymus gonionotus froma the Ranau Lake, South Sumatera has 100% matching ranges to the species from Memberamo River (Indonesia), India, Bangladesh, Thailand (Mae Khlong), Indo-Myanmar, and Malaysia_1. The lowest closeness (98.76%) is related to species from Thailand (Lower Ing). The Blast investigation appears us that the level of familiarity was very high, it is coming to 98-100% in Barbonymus gonionotus. Hampala macrolepidota had 100% matching ranges to the species from Indonesia (SouthaSumatera_1) and Vietnam. They had 99.05%-99.84% closeness from Malaysia_1,2&3, Indonesia (South Sumatera_2&3, Java and Bali_1,2&3).
Use of minute duckweed (Lemna perpusilla) for supplemental feed in catfish (Clariassp.) culture: determination of the optimal proportion using powersim simulation
Authors: Chrismadha Tjandra , Tanjung Livia Rossila , Sutrisno
Published: November 2021

Catfish farming is very profitable because the fish is easy to rear and can be harvested quickly. However, the cost of feed as the most significant component in production costs is currently getting higher. The availability and utilization of alternative feed is an urgent solution in creating sustainable catfish farming. This research was carried out during December 2020 – January 2021 in the Research Center for Limnology, Cibinong, Indonesia, which aims to determine the optimal proportion of minute duckweed (Lemna perpusilla) biomass added as feed supplemental to obtain an optimum growth of catfish fingerlings (Clariassp.). Catfish were reared for 63 days in nine aquariums with a density of 25 fish per aquarium. The commercial pellet given in the control aquarium was 100% pellet portion (5% of the total fish weight), while in the treatment aquariums were 60% and 40% of the total fish weight. As compensation, fresh duckweed (L. perpusilla) was providedad libitum. Fish were sampled twice to measure their weight and body length. This study showed that the proportion of duckweed as much as 40% as a supplement for commercial pellets could produce optimal catfish growth.