bluuebunny/crossref_metadata_2025 huggingface dataset:
Angle-of-attack characteristics of opposing jet for improving drag and heat reduction
Authors: Xu Haonan , Li Xueying , Ren Jing
Published: July 2024

While the opposing jet technique has the potential to achieve efficient drag and heat reduction, it can be severely affected by the incoming angle of attack. To analyze the angle-of-attack characteristics of opposing jet for improving drag and heat reduction, a three-dimensional blunt model was studied under various jet stagnation pressure ratios and angles of attack using the verified numerical method. The results showed that the enhanced reattachment shock on the windward side resulted in a higher pressure and temperature rise, which led to the deterioration of drag and heat reduction. Under the influence of the incoming angle of attack, the recirculation vortex transformed into a longitudinal vortex, resulting in a slanted U-shaped distribution of the surface pressure coefficient and Stanton number. Increasing the jet stagnation pressure ratio widened the coverage of the recirculation vortex on both the windward and leeward sides, which brought an improvement in drag and heat reduction. The interaction between the incoming angle of attack and the opposing jet caused a double-peak distribution of Stanton number due to the recirculation vortex reattachment and the compression of the incoming flow. The inclined opposing jet could reduce the peak values of pressure coefficient and Stanton number when subjected to the incoming flow with an angle of attack by spreading the recirculation vortex along the windward side. There should exist an optimal inclination angle that can effectively reduce the peak caused by the compression of the incoming flow without generating an excessive peak due to the recirculation vortex reattachment.
Effects of polar discontinuities and stacking sequences on ferromagnetic properties at La0.67Sr0.33MnO3/SrCuO2 interfaces
Authors: Zhang Jian , Huang Haoliang , Cui Zhangzhang , Shan Zheling , Wang Lenan , Luo Yanli , Jiang Zhongyuan , Wang Jianlin , Huang Qiuping , Fu Zhengping , Lu Yalin
Published: July 2024

Polar discontinuities occur in oxide heterostructures due to varying net charges in the sub-unit cell layers. These polar discontinuities lead to structural reconstruction and often create diverse functionalities. This work constructs polar discontinuous in La0.67Sr0.33MnO3/SrCuO2 (LSMO/SCO) heterostructures on a (001)-orientated SrTiO3 (STO) substrate under different configurations. By changing the growth order of LSMO and SCO, we found two different compensating mechanisms for polar discontinuity. When LSMO is grown on SCO, interfacial polarity discontinuities result in the generation of a large number of oxygen vacancies within the LSMO film. Thus, the LSMO magnetism deteriorates. For the SCO/LSMO/SCO trilayer, the SCO capping layer can recover the LSMO magnetism. The scanning transmission electron microscope results show an atomic reconstruction at the SCO-on-LSMO interface and several oxygen vacancies at the SrO sublayer. The interface reconfiguration releases the polar energy, thereby inhibiting the generation of oxygen vacancies and improving the ferromagnetism of the LSMO film. Our work studies the impact of polar discontinuity at the interface, providing insights into the effects of interface polar discontinuities on functional materials.
Solvothermal synthesis of crystalline 2D bismuth telluride with an isoelectronic dopant
Authors: Gray Lindsey J. , Swathi Kadaba , Mumbaraddi Dundappa , Carlson Timothy W. , Marcus Gabriel , Carroll David L.
Published: July 2024

In this work, we present a solvothermal, in situ doping methodology for synthesizing crystalline doped 2D bismuth telluride (Bi2Te3) nanoplates. Isoelectronic antimony (Sb) substitution at the bismuth (Bi) site is chosen to minimize the lattice strain in the nanostructure. Using a combination of x-ray techniques and electron microscopy, we demonstrate that the rhombohedral crystal structure (space group R3̄m), characteristic of Bi2Te3 is preserved in few-quintuple-layer, hexagonal nanoplates. Our findings reveal a uniform dispersion of Sb within the nanoplates up to an atomic concentration of 1%. Beyond this threshold, a disordered SbTe alloy begins to form along the crystal edges in addition to Sb substitution at the Bi sites in the bulk, restricting further growth of the nanoplates. In addition, we examine the different stresses that develop within the nanoplates as lattice strain increases due to Sb substitution. This study provides fundamental insights into the dopant’s effect on the self-assembled growth of electronically relevant 2D crystals.
The distributed strategy for asynchronous observations in data-driven wildland fire spread prediction
Authors: Zha Mengxia , Wang Zheng , Ji Jie , Zhu Jiping
Published: July 2024

Background Asynchronous observations refer to observations that are obtained at multiple moments. The observation moments of fire fronts may differ throughout an entire wildfire area. Asynchronous observations include historical data, which hinders the effectiveness of data assimilation due to the lack of timely updates on changing fire fronts. Aims This paper proposed a distributed strategy combined with the Ensemble Transform Kalman filter (ETKF-distributed) for asynchronous observations. It can assimilate fire fronts immediately at any location by using new matching schemes between prediction and observation. Methods The ETKF-distributed undergoes testing using a wildland fire generated based on real terrain, vegetation, and historical weather data from the local area. In addition, the ETKF and ETKF-centralised proposed in our previous work were employed as comparisons. Observing System Simulation Experiments were conducted to generate asynchronous observation fire fronts. Key results The benefit of immediate assimilation enables the new method to maintain high accuracy predictions. Conclusions The allocation of observation resources can be focused in regions with high rates of speed when employing ETKF-distributed. Implications The ETKF-distributed has high efficiency and adaptability, making it highly promising for implementation in wildfire prediction.
Transoceanic pathogen transfer in the age of sail and steam
Authors: Blackmore Elizabeth N. , Lloyd-Smith James O.
Published: July 2024

In the centuries following Christopher Columbus’s 1492 voyage to the Americas, transoceanic travel opened unprecedented pathways in global pathogen circulation. Yet no biological transfer is a single, discrete event. We use mathematical modeling to quantify historical risk of shipborne pathogen introduction, exploring the respective contributions of journey time, ship size, population susceptibility, transmission intensity, density dependence, and pathogen biology. We contextualize our results using port arrivals data from San Francisco, 1850 to 1852, and from a selection of historically significant voyages, 1492 to 1918. We offer numerical estimates of introduction risk across historically realistic ranges of journey time and ship population size, and show that both steam travel and shipping regimes that involved frequent, large-scale movement of people substantially increased risk of transoceanic pathogen circulation.
Cell–cell transfer of adaptation traits benefits kin and actor in a cooperative microbe
Authors: Subedi Kalpana , Roy Pravas C. , Saiz Brandon , Basile Franco , Wall Daniel
Published: July 2024

Microbes face many physical, chemical, and biological insults from their environments. In response, cells adapt, but whether they do so cooperatively is poorly understood. Here, we use a model social bacterium,
Myxococcus xanthus
, to ask whether adapted traits are transferable to naïve kin. To do so we isolated cells adapted to detergent stresses and tested for trait transfer. In some cases, strain-mixing experiments increased sibling fitness by transferring adaptation traits. This cooperative behavior depended on a kin recognition system called outer membrane exchange (OME) because mutants defective in OME could not transfer adaptation traits. Strikingly, in mixed stressed populations, the transferred trait also benefited the adapted (actor) cells. This apparently occurred by alleviating a detergent-induced stress response in kin that otherwise killed actor cells. Additionally, this adaptation trait when transferred also conferred resistance against a lipoprotein toxin delivered to targeted kin. Based on these and other findings, we propose a model for stress adaptation and how OME in myxobacteria promotes cellular cooperation in response to environmental stresses.
Political language gaffes and the importance of Hearer’s meaning
Authors: Tincheva Nelly
Published: July 2024

Drawing on Hansen and Terkourafi’s (2023) model of Hearer’s meaning, the paper discusses cognitive mechanisms through which hearers interpret political language gaffes (e.g. former U.S. President Trump’s “Despite the constant negative press covfefe”). The paper approaches political language gaffes as dependent on a high degree of blending between textual-and-discursive frames and social-world frames. The dataset analysis demonstrates how a Hearer’s difficulty in interpreting a gaffe-y utterance can shift Hearer’s focus (a) from one frame element (e.g. speaker, hearer, effect of utterance on hearer) to another, and (b) from a discursive frame to a social-world frame. The paper demonstrates how, while looking to pinpoint the contextual relevance of an utterance, a Hearer can simultaneously shift focus and vary the scope of cognitive structures from which Hearer can derive meaning. The paper also suggests how analyses of political language gaffes can contribute to research on sociopragmatic topics such as Speaker’s accountability, pragmatic competence, pragmatic failure, non-propositional effects, etc.
TLNRD1 is a CCM complex component and regulates endothelial barrier integrity
Authors: Ball Neil J. , Ghimire Sujan , Follain Gautier , Pajari Ada O. , Wurzinger Diana , Vaitkevičiūtė Monika , Cowell Alana R. , Berki Bence , Ivaska Johanna , Paatero Ilkka , Goult Benjamin T. , Jacquemet Guillaume
Published: July 2024

We previously identified talin rod domain-containing protein 1 (TLNRD1) as a potent actin-bundling protein in vitro. Here, we report that TLNRD1 is expressed in the vasculature in vivo. Its depletion leads to vascular abnormalities in vivo and modulation of endothelial cell monolayer integrity in vitro. We demonstrate that TLNRD1 is a component of the cerebral cavernous malformations (CCM) complex through its direct interaction with CCM2, which is mediated by a hydrophobic C-terminal helix in CCM2 that attaches to a hydrophobic groove on the four-helix domain of TLNRD1. Disruption of this binding interface leads to CCM2 and TLNRD1 accumulation in the nucleus and actin fibers. Our findings indicate that CCM2 controls TLNRD1 localization to the cytoplasm and inhibits its actin-bundling activity and that the CCM2-TLNRD1 interaction impacts endothelial actin stress fiber and focal adhesion formation. Based on these results, we propose a new pathway by which the CCM complex modulates the actin cytoskeleton and vascular integrity.
Solitons and Their Biperiodic Pulsation in Ultrafast Fiber Lasers Based on CB/GO
Authors: Ju 居 Zhen-Tao 震涛 , Si 司 Zhi-Zeng 志增 , Yan 严 Xin 鑫 , Dai 戴 Chao-Qing 朝卿
Published: July 2024

The carbon black (CB) is introduced to manufacture CB/graphene oxide (GO) composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber lasers. At a central wavelength of 1555.5 nm, the stable mode-locked pulse with width of 656 fs, repetition rate of 20.16 MHz, and high signal-to-noise ratio of 82.07 dB is experimentally obtained. Additionally, experimental observations for pulsation phenomena of vector biperiodic solitons combining period-1 and period-17, period-2 and period-32, period-3 and period-36 are verified via simulations.
Microfluidic biosensors: exploring various applications through diverse bonding methods
Authors: Yang Qiuping , Zhu Zhiyuan
Published: July 2024

Biological sensors are widely applied in agriculture, biomedicine, food, healthcare, environmental monitoring, water quality, forensics, drug development, etc. Particularly the utilization of microfluidic technology has become prevalent in the development and manufacturing of biosensors for miniaturization, automation, and integration. Microfluidic biosensors have distinct advantages, including enhanced diffusive timescales, controlled concentration gradients, high throughput, high precision fluid manipulation, stable reaction environments and high sensitivity. From the perspective of sensor fabrication, bonding remains the crucial pathway in the pursuit of integrating microfluidic technology with biosensor chips, while various bonding methods are employed across different application domains. This paper delves into the classification, progress, and challenges associated with these bonding methods corresponding with various microfluidic biosensors in diverse applications. The review presented herein highlights the latest advancements in microfluidic biosensors based on diverse bonding methods, underscoring their significant application prospects and developmental potential within these fields.
p

T
-spectra, nuclear modification factors (R

AA
, and R

CP
) of (multi-) strange hadrons in Au+Au collisions at

s

NN

=

200 GeV with HYDJET++
Authors: Devi Gauri , Singh Arpit , Singh B K
Published: July 2024

In this article, we have reported the transverse momentum (p

T
) spectra and nuclear modification factors of (multi-) strange hadrons produced in Au+Au collisions at

s

NN

=

200 GeV using the Monte Carlo HYDJET++ model. For the present study, we have tuned few of the input parameters, in both soft as well as hard parts, of the model to appropriately describe the production of (multi-) strange hadrons. We have presented the p

T
-spectra of (multi-) strange hadrons in different centrality intervals. On comparing p

T
-spectra with the experimental data, we observe that the model does not achieve thermal equilibrium for kaons toward peripheral collisions and for omega baryons for all the centrality intervals. The R

AA
results obtained by the model reproduce the experimental data well while the R

CP
results show less suppression at higher p

T
than the experimental data. Further, HYDJET++ results are also compared with different theoretical models and discussed, wherever possible.
ANCF-based dynamic modeling of variable curvature soft pneumatic actuators with experimental verifications
Authors: Rong Yu , Gu Guoying
Published: July 2024

Accurate and computationally efficient models of soft pneumatic actuators are crucial for utilizing their compliance in various fields. However, existing research primarily relies on the piecewise constant curvature assumption or the quasi-static assumption, only valid in limited situations. In this paper, we present a dynamic model based on absolute nodal coordinate formulation (ANCF) that simultaneously accounts for variable curvature deformation and dynamic properties. To this end, deformed configurations of soft pneumatic actuators are firstly discretized into ANCF-based beam elements. Based on this parameterization method, the dynamic model is derived by the principle of virtual work. After identifying model parameters, Newmark algorithm is utilized to solve the dynamic model in real-time, averagely consuming 6.76 s of a 10 s simulation. The derived dynamic model is experimental verified using a soft pneumatic actuator. The experimental results demonstrate that the maximum simulation errors of the tip remain below 2.5% of the actuator’s length when the actuator is subjected to various pressure and tip loads. In addition, the overshoot behavior and period of vibration in the oscillations are also predicted by the dynamic model. Moreover, the dynamic model exhibits an average 46.53% reduction in simulation error compared with the static ANCF-based model. Overall, this work paves the way to a deeper insight to dynamic motion analysis of soft pneumatic actuators.
The non-minimally coupled symmetric teleparallel gravity with electromagnetic field
Authors: Doyran Beyda , Sert Özcan , Adak Muzaffer
Published: July 2024

We construct a symmetric teleparallel gravity model which is non-minimally coupled with electromagnetic field in four dimensions inspired by its Riemannian equivalent. We derive the field equations by taking the variation of this model, which is written here for the first time. Then, we find some classes of spherically symmetric static solutions by the coincident gauge of symmetric teleparallel spacetime.
Designing an OAM fiber with a two-layer seven-core structure to support 322 OAM-mode transmissions
Authors: Wang Xiaohui , Deng Dongdong , Ji Xinchen , Zhang Hui , Xu Liang , Rui Jiawei , Yu Yongze , Mao Shuai , Wang Yang , Song Yingxiong , Pang Fufei , Zhuang Liyun , Yang Song , He Xiaofeng , Wang Chao , Zhu Tiezhu , Yang Yudong
Published: July 2024

In this paper, a two-layer seven-core structural fiber (TLSCSF) is proposed to support and improve the propagation of more orbital angular momentum (OAM) mode beams, thus increasing the transmission capacity and spectrum efficiency (SE) of an optical communication system. The TLSCSF is composed of seven sub-cores, each containing two inner and outer layers of core rings and a central air hole. The two core rings are prepared using two materials with different doping concentrations. The supported OAM modes can be propagated in the fiber core ring. A finite element method (FEM) is used to analyze the designed fiber, and the calculated results show that the TLSCSF can stably transmit 322 OAM modes without higher order radial modes in the wavelength range of 1.5∼1.6 um. The corresponding effective refractive index difference between two adjacent vector modes (HE/EH) is more than 10−4. The measured effective mode areas (Aeff) and the confinement losses (CL) of HE or EH modes are larger than 54 um2 and smaller than 10−10 dB m−1, respectively. Moreover, the calculated dispersion variations and the mode qualities are lower than 230 ps nm−1 km−1 and more than 90%, respectively. Finally, the 10ps walk-off lengths of all vector modes supported by TLSCSF at a wavelength of 1.55 um are also evaluated, where the measured results show that except for HE2,1 and EH1,1, all other modes achieve a 10ps walk-off length of the order of 103 to 105. Consequently, the TLSCSF can contributes to improving the channel capacity and SE by supporting 322 fundamental radial OAM modes with robust performances in an optical communication system.
Nanoscale pattern formation on surfaces by cluster ion beam irradiation
Authors: Jiménez-Sáez J C , Muñoz S , Palacios P
Published: July 2024

Ion beam sputtering is a solid-surface nanostructuring procedure applicable to any type of material. In this study, we are interested in the bombardment of a metallic surface, specifically, of a Co(110) surface bombarded with Ar clusters at oblique incidence. The bombardment with clusters accentuates the effect of surface ripple formation. Sputter erosion and surface atomic redistribution are the processes that determine the morphological evolution of the surface from the collisional point of view. The importance of these processes was analyzed for different angles of incidence in the bombardment with very small clusters and atoms while always maintaining the same fluence. The sputter yield increases with the number of atoms in the cluster for angles greater than 50°; while for the rest, it barely experiences any increase. Unlike sputtering, displacements increase as the cluster size increases above the critical angle. Moreover, horizontal displacement only shows some sign of saturation for angles close to the normal. An analysis of redistributed volumes and previous data suggest that sputtering drives the ripple effect for grazing angles and ones close to these. It is also responsible for the enhancement effect in the cluster bombardment. For the rest of the angles, the weight of the redistribution is decisive. There is a proportional relationship between the emptied volume and the horizontal displacement.
Radiation shielding competence of SeTeSnIn chalcogenide glassy system: resistance against gamma irradiation
Authors: Saraswat Kaushal , Pal Shiv Kumar , Khattari Z Y , Dahshan A , Mehta Neeraj
Published: July 2024

This paper reports the study of the high-energy radiation shielding characteristics of the STS glassy system. Further, the work investigates the effect of indium concentration on the high energy radiation shielding characteristics of the STS glassy system. For this purpose, a glassy Se78-xTe20Sn2Inx (x = 0, 2, 4, and 6) system was synthesized using a renowned melt quench technique whose density was measured through the Archimedes method. We have utilized an online platform, i.e., Phy-X/PSD software, to measure the different radiation shielding parameters of the SeTeSnIn glassy system. Several shielding parameters such as linear and mass attenuation coefficient, half value layer (HVL), mean free path (MFP), effective atomic number (Z

eff
), effective electron density (N

eff
), effective conductivity (C

eff
), equivalent atomic number (Zeq), energy absorption build-up factor (EABF), exposure build-up factor (EBF), and fast neutron removal cross-section (FNRCS) have been measured in the energy range of 15 keV to 15 MeV.
Multi-frequency and multi-functional optical switch based on dual plasmon-induced transparency
Authors: Li Hongjian , Li Xiaoyan , Luo Yuguang , Gao Enduo
Published: July 2024

Research into multi-frequency and multi-functional optical switches for complex applications is pioneering territory. By employing a single-layer structure comprising three distinct graphene strips, we successfully created a dual-PIT effect through the destructive interference among two bright modes and a dark mode. The numerical simulations were corroborated by coupled mode theory, reflecting a high degree of consistency between the theory and the simulations. Remarkably, the modulation of the Fermi level in graphene metamaterials through gate voltage enabled the realization of asynchronous optical switches capable of operating at six, five, four, and three frequencies. Notably, the six-frequency switch exhibited an impressive modulation depth of 88.54% and an insertion loss of just 0.15 dB, highlighting its superior performance. This study lays a solid foundation for future multi-frequency and multi-functional optical switch designs, offering significant implications and practical applications.
An energy concisions analytical modelling approach with experimental verification for cutting performance assessment in EDM of Ti-based superalloy
Authors: Ishfaq Kashif , Sana Muhammad , Mahmood Muhammad Arif , Anwar Saqib
Published: July 2024

Electric discharge machining (EDM) is a stochastic process which is commonly engaged for cutting of Ti-based difficult-to-cut alloys. Experimental investigation in EDM is costly and requires significant amount of time due to the complex nature of the process. Moreover, the energy intensive nature is another criticism associated to this technique. Therefore, this research is focused on developing an energy conscious mathematical model of the process while considering the categorical parameters like type of dielectric, electrode and nano-powder along with pulse time ratio. Taguchi design of experiment (DOE) has been executed for the experimentation. The comprehensive analysis of the findings depicts transformer oil (TO) delivers a remarkable improvement in MRR and SEC in comparison to other dielectric choices. Furthermore, brass electrode stands out for achieving the best surface finish. When it comes to micro-additives, SiC exhibits substantial potential in increasing MRR, and graphite gives a better surface finish. The process has also been effectively modeled which helps to predict material removal rate (MRR), surface roughness (SR) and specific energy consumption with decent precision which is the key contribution of this study. 3D simulation for EDM illustrates that the features of the crater are defined by the liquefied region, whilst the dynamics of the mushy zone play a crucial role in controlling and characterizing the microstructure size progression. The confirmatory experimental results revealed that the use of optimized parametric combinations demonstrate 90.87% improvement in MRR, 52.07% reduction in SR and 96.19% decrease in SEC in contest to the responses’ values obtained at non-optimal settings.
Calculation of electron-impact ionization of various benzene derivatives
Authors: Krishnadas Anirudh , Sinha Nidhi , Kirchner Tom , Antony Bobby
Published: July 2024

Calculations of the electron-impact ionization cross-section of pyrene, anthracene, benzoyl chloride, benzophenone, and phthalonitrile are reported over a wide energy range. A comparison of theoretical models, viz. spherical complex optical potential (SCOP), pixel counting method (PCM), and the binary encounter Bethe (BEB) model is carried out. SCOP calculations provide the inelastic cross-section, and the ionization cross-section is extracted from it. This result is modified with PCM, a model previously applied to ion collisions which takes geometric screening corrections into account. The BEB model is used as an independent approach to calculate the ionization cross-section. It is demonstrated that all model results are in reasonable agreement with each other. Comparison is also made with other theoretical data where available.
Dynamics of a two-level atom in the presence of a medium-assisted thermal field
Authors: Gonouiezadeh Razieh , Safari Hassan
Published: July 2024

In this paper, the time evolution of a two-level atom in the presence of a medium-assisted thermal field is explored through which the formula for the decay rate of an excited atom is generalized in two aspects. The obtained formula applies to a thermal electromagnetic field as well as to the presence of an arbitrary arrangement of magnetoelectric media. In order to be general with respect to the material environment, the Green’s function approach is used. It is shown that the non-zero temperature contributes to the decay rate via an additive term that is equal to the zero-temperature result multiplied by two times the photon number at the atomic transition frequency.
Interference aided finite resonant response in an undamped forced oscillator
Authors: Haque Shihabul , Bhattacharjee Jayanta K
Published: July 2024

We apply perturbative techniques to a driven undamped sinusoidal oscillator at resonance. The angular displacement, θ, obeys the dynamics

θ
¨

+

ω

2

sin
⁡
θ
=
H
cos
⁡
ω
t

. The linearized approximation gives a divergent response (at long times) but the nonlinear terms make the response finite. We address the nonlinearity-induced finiteness in two ways by separately treating the short and long time scales. At long times, we use the traditional perturbative techniques to extract two drive dependent behaviours—one, the amplitude of oscillation scales as

(
H

/

ω

2

)

1

/

3

and, two, the time period of the slow mode varies as

(
H

/

ω

2

)

−
2

/

3

. For the early time behaviour, on the other hand, we devise an alternate perturbative expansion where the successive terms get larger with the order of evaluation but have alternating signs. The alternating signs (phase differences) between these terms leads to adestructive interference like effect. A careful consideration of this destructive interference like effect between successive terms leads to a finite response which describes the initial behaviour of the amplitude of the response reasonably correctly. We further note that for larger drive values, the system seems to undergo a first order transitional behaviour with a sudden jump in the largest Lyapunov exponent
Wind resource assessment for turbine class identification in Bayanzhaganxiang, China
Authors: Augusto G , Gatus C L , Ubando A , Gan Lim L , Gonzaga J
Published: July 2024

The wind resource assessment has been used effectively to identify the classification of wind turbines at a particular wind farm site. The current study used WAsP software and various statistical methods such as graphical, energy pattern factor, standard deviation, and Rayleigh distribution methods to find the Weibull parameters by evaluating the raw data collected from August 2005 until July 2006 at four (4) different heights of the meteorological mast station in Bayanzhaganxiang, China. The Weibull parameters were utilized to find the annual mean wind speed, probability density, and cumulative distribution functions of wind conditions at the reference heights of 70 m, 50 m, 30 m, and 10 m. The wind shear coefficient was 0.130 with an overall roughness factor of 0.0385 m, suggesting the site vicinity is an open country with no significant structures and vegetation. The results also showed that the post-processed output from WAsP and standard deviation method at the sensor’s height of 70 m have a correlation coefficient and confidence level of 0.99977 and above 95%, respectively. Based on the turbine classification from GL Wind 2003 and IEC 61400-1 Ed.2, it was found that the turbine class ideal for the site is class III wind turbines with an annual mean wind speed of 7.439 m/s at a hub height of 99 m. The measured wind power density at hub height was calculated according to IEC 61400-12-1, which yields 464.36 W/m2. The characteristic wind turbulence at 70 m high is IEC subclass B. Among the selected wind turbines, the net annual energy production with efficiency is 8,059.57 MWh/year using Avantis AV1010, with the highest capacity factor of 40.05%. It has been found that the lowest energy generation cost is US$ 0.0292/kWh for a period of 20 years.
Leveraging media for demand control in an optimal network of renewable microgrids with hydrogen facilities in South Korea
Authors: Ifaei P , Park J K , Woo T Y , Jeong C H , Yoo C K
Published: July 2024

In pursuit of a sustainable 2030 strategy in the Republic of Korea, this study addresses the oversight in recent optimal renewable energy microgrid designs, which, despite encompassing all feasible renewable sources, neglected the pivotal role of hydrogen as an energy carrier. This research explores the feasibility of reprogramming media platforms to dynamically shape energy consumption during peak intervals. It further proposes the retrofitting of microgrids with industrial hydrogen production and storage facilities, aligning with controlled electricity demand. A comprehensive social survey investigates the impact of media content on energy-conscious behaviour and cooperation, specifically targeting energy savings during peak hours. Utilizing a probabilistic model, the study quantifies responses from the surveyed sample and decomposes the energy demand time series to reveal three new consumption patterns: demand reduction by lowering residential electricity consumption at peak intervals without shifts, intense demand shifting by redistributing electricity consumption from peaks to valleys without human intervention, and moderate demand shifting achieved through cooperation with consumers. With these novel energy demand patterns in hand, the study optimally designs renewable microgrids in 17 sites in South Korea, comparing two strategies: Plan A, involving electrolysis-based hydrogen production and storage tanks, and Plan B, which excludes hydrogen facilities. Comparative results demonstrate that media content contributes to a 10.28% and 16.11% reduction in peak electricity consumption, with and without human intervention, respectively. In Plan B, a demand cut saves 937.3 MWh/yr, resulting in a 12.88% reduction in the levelized costs of electricity (LCOE) and a 4.67% reduction in net present costs (NPC) of optimal renewable microgrids in Korea. Conversely, in Plan A, intense demand reduction exhibits superior performance, leading to $981K less NPC, 1,046 MWh/yr less excess electricity, and a 3.76% smaller LCOE. The study recommends the implementation of smart gadgets to control residential electricity consumption, producing industrial hydrogen at Korean sites based on consumer attention and agreement with specific media content. However, it underscores the importance of studying the socio-psychological effects of this plan in future research.
Electrocoagulation treatment for Remazol Brilliant Blue R (Reactive Blue 19) removal of textile dye simulated wastewater using iron-aluminum electrodes
Authors: Cruz K D , Camacho S L A , Rodenas H M P
Published: July 2024

The presence of non-biodegradable dyes, such as Remazol Brilliant Blue R (Reactive Blue 19), in wastewater poses a significant environmental challenge. This study investigates the application of electrocoagulation using iron-aluminum (Fe-Al) electrodes to efficiently remove Reactive Blue 19 dye from simulated textile dye wastewater. It considers various parameters such as electrode material, current, stirring speed, as well as the influence of sodium chloride acting as a supporting electrolyte to enhance conductivity. Additionally, it evaluates the economic feasibility through electrode consumption analysis. The experimental setup involved a designed reactor with aluminum and iron electrodes arranged at bipolar parallel connection, along with a 30-minute electrocoagulation process conducted at ambient temperature and subsequent filtration of the treated wastewater for UV-VIS analysis. The optimal parameter combination obtained consists of Fe-Al electrode material, a 3 A current, and a 200-rpm stirring speed, achieving 96.87% dye removal. Furthermore, extending the operating time to 60 minutes improved the removal by 99.15%. Under these optimal conditions, the energy consumption measured was 36 kWh/m3. The high dye removal rate obtained shows the effectiveness of this electrocoagulation process in treating Reactive Blue 19 simulated wastewater. A t-test, employed as a hypothesis testing technique with a significance level of 0.05, confirmed the optimal levels of the factors and interactions within the treatment process. A remarkable coefficient of determination of 0.9794 in the dye removal sensitivity analysis signifies a strong goodness of fit, indicating that these three (3) parameters collectively explain how they affect the outcome while accounting for dye removal efficiency variation. These results showed that electrocoagulation is a promising technology for treatment of Reactive Blue 19 dye wastewater.
Biochar and syngas from wet torrefaction of oil palm empty fruit bunches and palm oil mill effluent: A renewable energy approach
Authors: Mohamad Aziz Nur Atiqah , Ling Yu Kai , Mohamed Hassan , Zainal Bidattul Syirat , Zaman Halimah Badioze , Alsultan Abdulkareem Ghassan
Published: July 2024

Palm oil mill effluent (POME) and oil palm empty fruit bunches (EFB) constitute the highest waste generated in the mill. This study investigates thermochemical approaches, specifically wet torrefaction and gasification, aiming to transform these wastes into higher-value products such as biochar. Wet torrefaction was initially applied to EFB and POME at 200 °C, with a heating rate of 5 °C/min for 30-min residence time under nitrogen-inert conditions, resulting in a solid yield of 82%. This process led to a notable increase in the heating value of raw EFB by 30.6%, from 17.3 to 22.6 MJ/kg. Subsequently, the product underwent gasification at various temperatures ranging from 600 to 800 °C, with a constant heating rate of 10 °C/min, gas flow rate of 20 ml/min, and a retention time of 30 min. The gasification reaction improved the solid yield and resulted in the generation of liquid products and syngas. The results indicated that 45-59% of biochar, 12-17% of bio-oil, and 30-39% of syngas were produced. The syngas composition, determined using gas chromatography, revealed the presence of CO2, H2, CH4, and CO. The solid product, characterised by a higher heating value, is a viable alternative for solid fuel. The findings suggested that both wet torrefaction and the gasification process have the potential to address the abundance of palm mill waste issues and offer an alternative approach for utilising and generating energy within the mill.
Synthesis of Ceiba pentandra biodiesel using ultrasound and infrared radiation: Comparison and fuel characterisation.
Authors: Milano J , Tiong S K , Silitonga A S , Chia S R , Ong M Y , Kusumo F , Sebayang A H , Yusof T , Kalam M A
Published: July 2024

The continuous expending of the economy and population in modern society has caused an increase in energy usage. Currently, fossil fuels and renewable energy are used to generate energy, contributing to greenhouse gas emissions. A significant effort has been made globally to address the issue of rising emissions by boosting the usage of renewable energy. In comparison to fossil fuels, biodiesel has many benefits, including the ability to be produced from a wide range of feedstocks, the ability to be renewable, and the reduction of atmospheric pollution emissions. Besides, advanced technologies can help the biodiesel sector meet the energy demand while producing high-quality biodiesel. The Ceiba pentandra was used for biodiesel production using ultrasound-infrared applications in the present research work. The study aims to produce biodiesel for a better conversion rate and improve fuel properties. Comparisons were conducted using a combination of infrared ultrasound versus ultrasound irradiation. The results show that ultrasound produced the highest yield of 98.76% when the conditions were as follows: methanol/oil ratio: 60%, KOH: 1%, reaction time: 50 minutes. Yet, the addition of infrared on ultrasound has also produced a high conversion yield in a shorter time than ultrasound. A 98.42% biodiesel yield option when using infrared-ultrasound irradiation with conditions as follows: methanol/oil ratio: 60%, KOH: 1%, reaction time: 30 minutes. As both applications were examined, the ultrasound-infrared application was preferable in saving time and energy constraints for biodiesel production. The fuel properties were found to be equivalent to ASTM D6751 and EN 14214 biodiesel standards.
Assessment of energy saving and CO2 emission mitigation of low-lift cooling in computer hardware manufacturing industry: A case study in Thailand
Authors: Nizigiyimana J , Chaiwiwatworakul P
Published: July 2024

Released heat from production process contributes the largest proportion of cooling load in computer hardware manufacturing industry. According to traditional design practice, chiller plant produces chilled water at a temperature of 7°C to treat the entire load from the production process and from the comfort air-conditioning in buildings. However, the heat from the process is solely the sensible component where high-temperature chilled water (e.g., 15°C) can be used for the heat removal, the chillers equipped with low temperature-lift technology thus offer a great opportunity to improve the plant’s cooling performance. Under the critical global warming situation and the need of decarbonizing industry, this paper investigated the energy saving and CO2 emission mitigation potential of the low-lift technology by which the chiller plant of high-temperature chilled water (15°C) is dedicated for the production process cooling, and the traditional chiller plant of the low-temperature chilled water is used to serve the building air-conditioning. The study site was a large factory of computer hardware manufacturing in Thailand. Through detailed energy auditing, the cooling load profile of the production process was established, and it was used to design the low-lift chiller plant. The annual simulation results showed that in our study case the low-lift chiller plant together with variable motor speed control had 31.6% higher cooling performance than the traditional chiller plant. The plant could reduce the energy consumption by 5,550 MWhelec/year. As the CO2 emission of the grid power in Thailand was 0.47 kgCO2/kWh in 2023 and it was expected to reduce to 0.35 kgCO2/kWh in 2050, the CO2 emissions from implementing the low-lift cooling could be reduced by 49,400 TonCO2 over a course of the 20-year project lifetime. The study results encouraged the low-lift cooling technology as a practical energy efficiency measure in computer hardware manufacturing industry. To our knowledge, while past research focused on the low-lift cooling in building air-conditioning, the study was the first potential assessment project of the low-lift cooling as a deep decarbonization technology for the computer hardware manufacturing industry in Thailand.
Air quality monitoring using drones (UAV)
Authors: Alberto Bernabeo R , D’Alessandro Gianmarco , Ceruti Alessandro , Tositti Laura , Nguyen Nhan , Ho Thanh Phuoc
Published: July 2024

Air pollution causes many diseases and is a major environmental threat, therefore, it is essential to monitor and improve the air quality. With this work, we aim to assess atmospheric pollution using drone-mounted air sensors, with specific applications in Vietnam. We aim to measure Green-House Gas (GHG) emissions and other pollutants in urban and non-urban areas of interest including, but not limited to landfills and airports, to evaluate the effects of pollution on climate and health. The project will use a novel and creative approach to collect three-dimensional atmospheric data using smart sensors mounted on Unmanned Aerial Vehicles (UAVs). UAVs have been extensively applied in recent years, both in Vietnam and on a global scale, to multiple fields and with different scopes. Surveying, crop monitoring, irrigation and fertilization, surveillance and rescue support, and 2D and 3D mapping, are just a few examples of how UAVs can be used for agriculture, archaeology, forestry, urban planning, and architecture. In this project, we develop an integrated system of UAVs and smart sensors for air quality monitoring. To develop mitigation and adaptation strategies for reducing the environmental impact of transport, it is imperative to assess the emission sources and trends. Therefore, we are developing a system able to collect comprehensive atmospheric data using remote aerosol sampling, and chemical speciation. Furthermore, the potential of using smart sensors on other flying devices is explored.
A self-powered spring-based triboelectric vibration sensor
Authors: Ganesan V , Chee P S , Goh Q L , Lim E H , King Y J , Chong L H
Published: July 2024

Self-powered vibration sensors have gained attention due to their versatility. However, a limitation of many existing self-powered sensors is their single-direction functionality, which hinders their effectiveness in capturing multidirectional human movement’s swinging motions. To address this, this study introduces an innovative self-powered vibration sensor based on the triboelectrification effect of an inverted pendulum metal ball. This novel sensor excels at detecting micro-vibrations through the freestanding sliding electrification of a metal ball using Kapton tape. The generated charge is transferred through interdigital electrodes arranged in a spiral pattern. To ensure adaptability to various motion types, the metal ball is affixed to a spring and configured as an inverted pendulum. This setup allows the sensor to detect both linear and rotary motions across a range of acceleration levels. The fabricated sensor exhibits remarkable sensitivity, measuring 0.203 V/mm. It was affixed to the human body to detect low-frequency vibrations, particularly those below 20 Hz. Impressively, it can detect millimeter-scale vibrations, even up to 3 mm, at different rotational angles (0°, 30°, 60°, and 90°). This outcome highlights the promising performance of our vibration sensor in the field of human motion monitoring, making it a significant advancement in the realm of self-powered vibration sensors.
A visualization study of a confined vapor chamber with conical microstructure applied in data centres
Authors: Liu Yijia , Qin Siyu , Yang Changming , Meng Xiangzhao , Yang Chun , Jin Liwen
Published: July 2024

With the development of the informatization technology, the scale of the data centre is expanding rapidly. The energy consumptions of the electronic equipment in the data centre are rising regularly, which lead to the thermal management becoming an argent issue to be settled. To realize the sustainable development of green data centre, the passive two-phase vapor chamber (VC) has turned into the focus of electronic cooling research. Constructing nucleation induced structures on the evaporation surface is an effective method to improve the performance of the vapor chamber. To address the problem of achieving enhanced boiling, a novel conical microstructure was designed in the vapor chamber with 50 mm height. The conical structure of 1 mm axial height was fabricated on the evaporation surface by computer numerical control (CNC) machining technology. A visualization experimental system was developed to investigate the effect of the conical microstructure on the two-phase behaviours, and the boiling heat transfer characteristics under different heating conditions (Q
in = 35 W, 50 W, 65 W) in a confined vapor chamber. The high-speed camera was used to capture the bubble behaviours. Experimental results found that compared with the smooth surface, the integration of the conical structure increasing the number of bubble nucleation sites and the bubble departure frequency. The bubble growth period at stable heating stage is 162 ms shorter than initial heating stage on the evaporation surface with conical structure. The thermal resistance (R
vc) of vapor chamber with conical structure is improved by 5.85% compared to the smooth one at Q
in = 65 W, which indicate that the conical microstructure can enhance the boiling heat transfer performance. This study aims to provide a reference for the design of thermal management system for green data centre.
Enhancing thermal comfort in buildings through the integration of phase change material on the building envelope: a simulation study
Authors: Bordoloi U , Das B
Published: July 2024

According to the report published by the International Energy Agency (IEA), active space cooling and air conditioning systems consume approximately 16% of the building sector’s final electricity consumption and contribute 3.94% of global greenhouse gas emissions. In this regard, the use of low-cost but effective passive solutions, such as organic phase change materials (PCM) on the building envelope, can provide high thermal mass and thus can lower the temperature fluctuation inside the building. In the current study, the potential of PCM-enhanced building envelopes to enhance thermal comfort has been studied. The study has been performed using the conduction finite difference (ConFD) algorithm in EnergyPlus software. A comparative study has been done for a traditional reinforced cement concrete (RCC) reference test room of size (5m x 6m x 3m) and another room of the same size with PCM-enhanced walls for the hot and humid climate zone of Guwahati (latitude 26.1, longitude 91.7), in India. A PCM thickness of 20 mm is used at the external surface of the wall between the red clay burnt brick (120 mm in thickness) and the cement plaster (25mm thick). The PCM used for the study is a biocomposite PCM, named WH-PCM, with a melting point of 31.5°C and thermal conductivity of 0.27 W/mK. The simulation results reveal that the R-value of the external wall of the room with PCM walls has been increased by 84.90% compared to the reference room with the incorporation of WH-PCM, resulting in a mean zone temperature difference of 0.3°C throughout the year. Also, the indoor thermal discomfort hours have been annually reduced by 15.82% with the use of WH-PCM when compared with the reference room. A similar temperature difference trend, which is 1.93°C, is also observed in the single PCM brick experimental result under identical testing conditions as a regular brick of the same size.