bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of an agile optical switcher based on a 1D silver plasmonic nanograting filled with a nonlinear Kerr material
Authors: Rashidi Arezou , Hatef Ali
Published: July 2023

In this paper, we investigate the nonlinear optical response characteristics of a metallic nanograting with nonlinear Kerr media within its slits using the finite element method. The proposed nanograting system is illuminated by a nanosecond Gaussian pulse laser under normal incidence and the electric filed pointing across the slits. The results show a perfect linear absorption at resonance wavelength thanks to the coupling of the surface plasmon resonance (SPR) mode and photon cavity mode. We simulate the transient nonlinear absorption variation of the system when the pulse laser is set up at either resonance or off-resonance wavelengths. The results indicate that the unit linear absorption drastically decreases by increasing the laser fluence around the center of the pulse. Interestingly, one can also enhance the weak linear off-resonance absorption to the value of unit by increasing the pulse laser fluence. The higher the laser fluence, the higher the maximum absorption contrast between linear and nonlinear regimes occurs owing to the nonlinear Kerr effect. Indeed, when the laser fluence reaches a critical value, it can excite the Kerr nonlinearity, which changes the coupling strength of SPR mode and the photon cavity mode leading to the absorption adjustment in the nanograting. These properties indicate the possibility of utilizing the proposed nanograting in dual functional absorber and nonabsorber systems, which make it an appropriate candidate for agile optical switching devices.
Quasinormal modes and grey-body factors of regular black holes with a scalar hair from the Effective Field Theory
Authors: Konoplya R.A.
Published: July 2023

The Effective Field Theory (EFT) of perturbations on an arbitrary background geometry with a timelike scalar profile has been recently constructed in the context of scalar-tensor theories. Unlike General Relativity, the regular Hayward metric is realized as an exact background metric in the Effective Field Theory with timelike scalar profile without resorting to special matter field, such as nonlinear electrodynamics. The fundamental quasinormal mode for axial graviational perturbations of this black hole has been considered recently with the help of various methods. Here we make a further step in this direction and find that, unlike the fundamental mode, a few first overtones deviate from their Schwarzschild limit at a much higher rate. This outburst of overtones occurs because the overtones are extremely sensitive to the least change of the near- horizon geometry. The analytical formula for quasinormal modes is obtained in the eikonal regime. In addition, we calculated grey-body factors and showed that the regular Hayward black hole with a scalar hair has a smaller grey-body factor than the Schwarzschild one. Integration of the wave-like equation in the time-domain shows that the power-law tails, following the ring-down phase, are indistinguishable from the Schwarzschild ones at late times.
Effective description of generalized disformal theories
Authors: Takahashi Kazufumi , Minamitsuji Masato , Motohashi Hayato
Published: July 2023

Generalized disformal transformations enable us to construct the generalized disformal Horndeski theories, which form the most general class of ghost-free scalar-tensor theories to this date. We extend the effective field theory (EFT) of cosmological perturbations to incorporate these generalized disformal Horndeski theories. The main difference from the conventional EFT is that our extended EFT involves operators with higher spatial derivatives of the lapse function. Our EFT also accommodates the generalized disformal transformation of U-DHOST theories.
f(T, B) gravity with statistically fitting of H(z)
Authors: Shekh S H , Myrzakulov N , Bouali A , Pradhan A
Published: July 2023

Some recent developments (accelerated expansion) in the Universe cannot be explained by the conventional formulation of general relativity. We apply the recently proposed f(T, B) gravity to investigate the accelerated expansion of the Universe. By parametrizing the Hubble parameter and estimating the best fit values of the model parameters b
0, b
1, and b
2 imposed from Supernovae type Ia, Cosmic Microwave Background, Baryon Acoustic Oscillation, and Hubble data using the Markov Chain Monte Carlo method, we propose a method to determine the precise solutions to the field equations. We then observe that the model appears to be in good agreement with the observations. A change from the deceleration to the acceleration phase of the Universe is shown by the evolution of the deceleration parameter. In addition, we investigate the behavior of the statefinder analysis, equation of state (EoS) parameters, along with the energy conditions. Furthermore, to discuss other cosmological parameters, we consider some well-known f(T, B) gravity models, specifically, f(T, B) = aT

b
+ cB

d
. Lastly, we find that the considered f(T, B) gravity models predict that the present Universe is accelerating and the EoS parameter behaves like the ΛCDM model.
Emergence of correlations in twisted monolayer–trilayer graphene heterostructures
Authors: Zhou 周 Zhang 璋 , Watanabe Kenji , Taniguchi Takashi , Lin 林 Xiao 晓 , Mao 毛 Jinhai 金海 , Gao 高 Hong-Jun 鸿钧
Published: July 2023

Twisted bilayer graphene heterostructures have recently emerged as a well-established platform for studying strongly correlated phases, such as correlated insulating, superconducting, and topological states. Extending this notion to twisted multilayer graphene heterostructures has exhibited more diverse correlated phases, as some fundamental properties related to symmetry and band structures are correspondingly modified. Here, we report the observations of correlated states in twisted monolayer–trilayer (Bernal stacked) graphene heterostructures. Correlated phases at integer fillings of the moiré unit cell are revealed at a high displacement field and stabilized with a moderate magnetic field on the electron-doping side at a twist angle of 1.45°, where the lift of degeneracy at the integer fillings is observed in the Landau fan diagram. Our results demonstrate the effectiveness of moiré engineering in an extended structure and provide insights into electric-field tunable correlated phases.
Accelerator-driven photon reference field for replacement of 137Cs γ-ray
Authors: Ishii Junya , Satoh Daisuke , Fujiwara Takeshi , Tanaka Masahito , Kato Masahiro , Kurosawa Tadahiro
Published: July 2023

A transition to a mechanical source for x-ray reference field is desired to replace high-activity Co-60 and Cs-137 gamma-ray sources for enhancing nuclear security and safety management. The National Metrology Institute of Japan (NMIJ) developed a new photon reference field using an electron beam from a linac with energy less than 1 MeV. The effective energy of the photon field is comparable with Cs-137 gamma-ray. The air kerma rate in the reference field was validated by comparing a commercial cavity ionization chamber to the NMIJ standard reference field. The calibration constants were consistent within 0.8% for every relative extended uncertainty (k = 2).
Study on Compensation of Blood Oxygen Sensor’s Ambient Light Based on GA-BP Neural Network
Authors: Zhu Yuxi , Wang Chongyang
Published: July 2023

In order to reduce the interference of ambient light on near-infrared blood oxygen sensors (used to measure oxygen saturation of human tissue or oxygen saturation of circulating blood during Extracorporeal membrane oxygenation treatment) and improve the measurement accuracy of a blood oxygen sensor, a compensation method of ambient light interference is proposed. This method does not need an ambient light sensor or an additional circuit. The interference intensity of ambient light is calculated by changing the light intensity value emitted by the LED in the sensor and combining the light intensity value received by the sensor. The Genetic Algorithms-Back Propagation(GA-BP) neural network is modeled, the detection light intensity value and the ambient light interference evaluation values are taken as the input characteristics, the blood gas analysis true value is taken as the expected output, and the network model is used for prediction. The results show that the accuracy of this method is higher than the traditional fitting results, and the error between the network prediction value and the true value of blood gas analysis is basically within 5%.
Energy Storage Configuration Method for Low-Voltage Distribution Stations Taking Into Account Economy and Power Supply Reliability
Authors: Fu Yu , Fang Yang , Li Wei , Ren Jiakuan , Jiang Fangxiang , Zhang Yang
Published: July 2023

To address the reliance on fossil fuels, a significant number of photovoltaic systems have been integrated into the power grid. This has led to a situation where the locally generated photovoltaic power cannot be consumed on-site, causing an increase in the voltage of the distribution network and potentially exceeding limits. Additionally, this results in an increase in network losses within the distribution network. Energy storage systems have a high degree of versatility and can be utilized to address the issue of misalignment between solar panel output and energy demand due to grid-connection of photovoltaic systems. This is achieved through the system’s quick charging and discharge capabilities, and its ability to control the charging and discharge state.This paper presents models for optimal energy storage allocation in both normal operations and failure situations. It outlines a process for allocating energy storage that balances economic considerations with power supply reliability. To illustrate the effectiveness of the energy storage system in enhancing the distribution network, a practical example is provided in a substation, both under normal and fault conditions.
Design of Clock Synchronization of Base Station by Using 8A34002
Authors: Zhao Qiancheng , Jiang Kai , Wang Shuai , Yu Fan , Xue Haijun , Zhao Xinxin
Published: July 2023

The stability of the entire base station depends on the synchronization of the base station’s clock. The clock synchronization management chip 8A34002 supports SyncE Ethernet and IEEE 1588. In this architecture, the GPS receiver, SSI, and master/slave switching device all emit PPS/TOD signals. PPS/TOD signals are input into the FPGA, which outputs one PPS/TOD signal. The PPS/TOD signal enters 8A34002 in this design scheme, and the DPLL of 8A34002 provides filtering and clock-following output. The 8A34002‘s signal output is used as the system’s clock after processing. The switching chip, X86 main control chip, and BBU base station board are all driven by the system clock, which serves as a reference clock. The 8A34002 uses four DPLLs, one each for the SyncE, PTP, GNSS, and test functions.
Design of the Paw of Wall-Climbing Robot with Spiny and Sensing Function
Authors: Li Rui , Yan Shuang , Zhou Chongchuan , Liu Zhongbang , Shou Mengjie
Published: July 2023

Paws are the key parts for wall-climbing robots to climb on vertical walls. Wall-climbing robots with spiny feet have important application value in the safety monitoring of buildings, bridges, tunnels, and other buildings. Researchers have designed a variety of spiny feet that can bear large weights and have strong adaptability. However, due to the lack of robot grasp state perception, it is difficult to complete the task normally when there are obstacles and complex walls. In this paper, according to the perceptual feedback mode of the foot of the domestic cat when climbing, a kind of paw with a spiny and sensing function is designed. The paw can give real-time feedback of the gripping force, which well copes with the failure of gripping force and helps the wall-climbing robot to cope with uncertain wall environment.
Grid-Connected PV Inverter Control Strategy Based on the Sliding Mode
Authors: Wu Jing-mei , Wang Xiao-ping
Published: July 2023

The Photovoltaic grid-connected inverter is an essential equipment of photovoltaic grid-connected system. Due to the disadvantages of the traditional PI control method for grid-connected photovoltaic inverters, this paper adopts the integral sliding mode variable structure to control grid-connected inverters. Grid inverter DC control mode was introduced in detail in the sliding mode variable structure control strategy. Using Matlab simulation platform to compare and analyze the traditional PI voltage compensation control strategy and sliding mode variable structure control strategy. From the waveform of the simulation output, the current harmonic at the output of the grid-connected inverter is reduced, and the power factor is increased, with the power factor is close to 1. The control precision, robustness and anti-interference ability of grid-connected system are improved. Which proved the feasibility and the superiority of the proposed control strategy.
Power Grid Fault Prediction System Collaborates with Power Supply Guarantee Command Platform for Smart Grid
Authors: Chang Yongzhe , Xiao Xinhang
Published: July 2023

The safe operation of power system is a pretty important part for the whole society and it is influencing everyone’s daily life. As the biggest power operation company, the State Grid Corporation of China has to ensure the normal operation of the power grid. However, the power system can be affected by several issues such as all kinds of extreme weather, aging of equipment, and with rapid development of the national economy and power industry, the electricity loads are becoming complicated and diversified. Due to the reasons above, pressure on the safe operation of the power grid is increasing significantly. In order to guarantee the safety of daily operation for power system, we propose a new system, including a fault predicting part and aftertreatment part. For the predicting part, machine learning technologies are used especially the Hawkes process model, to predict when and what kind of fault may happen, by which failures can be prevented effectively. In the aftertreatment part, a power supply guarantee command platform is established that can send abnormal information to headquarters at the very beginning and then our platform will search for the optimal maintainer intelligently to solve the problem immediately.
RS-Coded Cooperation Scheme Based on 2 × 2 Labeling Diversity
Authors: Chen Chen , Yang Fengfan , Xu Hongjun
Published: July 2023

This paper investigates the novel labeling diversity (LD) technique with two transmit antennas and receive antennas applied in the Reed-Solomon coded cooperative (RSCC) system to propose a novel RSCC-LD scheme over the Rayleigh quasi-static fading and frequency-flat fast-fading channels. Two separate RS codes over the same Galois field are deployed at the source and relay terminals, respectively with the relay RS code providing more extra redundancy. To optimize the use of the information contained in two RS codes, a novel joint decoding approach is developed at the destination terminal. The results of numerical simulation demonstrate that the proposed RSCC-LD has an obviously better performance than the non-cooperative RS coding scheme and RSCC scheme without LD. Furthermore, the performance of the RSCC-LD reveals the superiority of some other existing schemes.
Analysis and Modeling of System Performance Based on Random Matching Errors, Gradient Errors, and Finite Output Impedance of Current-source DAC
Authors: Ma Zhihua , Song Zheng , Yao Yao , Hu Jianguo
Published: July 2023

With the development of communication technology, the performance of digital-to-analog converters as the last link in signal processing is particularly important. This paper analyzes the errors of current rudder DAC and their effect on DAC performance. Different compensation methods are proposed to compensate for or eliminate the errors. Through system modeling, it is concluded that under the conditions of static parameters DNL<0.5LSB, INL<0.5LSB, dynamic parameters SFDR>90dB and SNDR>70dB, the random matching error should be less than 0.001, the gradient error less than 1E-5 and the admittance rate less than 1E-7. The correctness of the theoretical analysis can be verified through system modeling and simulation, providing accurate guidance direction for circuit design and greatly shortening the design cycle.
Research on Wireless Energy Transmission Systems of Coupled Nonlinear Resonator
Authors: Li Zhongkui , Wang Lejun
Published: July 2023

Due to environmental interference, device aging, and the strict requirements for the relative position of the transceiver coil during charging, we always hope that the output voltage and power can remain stable when the transmission distance of the transmitting and receiving coils changes in the largest range possible. However, once the relative position of the transceiver coil of the traditional linear magnetic coupling resonance WPT system changes, that is, when the transmission distance is not optimal, the transmission performance of the system will be seriously degraded. In practical applications, the charging equipment inevitably moves, and the harsh transmission conditions limit the wide application of WPT technology. To solve this problem, based on the nonlinear characteristics presented by the nonlinear Duffing resonance model, this paper proposes to use a reverse series varactor at the receiving end by adjusting the reverse bias voltage of the varactor. This method compensates for the transmission performance attenuation caused by the change of the coupling coefficient of the transceiver coil to maintain a high level of transmission performance when the relative distance between the transceiver coils is as large as possible.
Photo-assisted Cl-, Br- and I- production in caesium sputter ion source
Authors: Hossain A. , Tarvainen O. , Reponen M. , Kronholm R. , Julin J. , Kalvas T. , Toivanen V. , Kivekäs M. , Laitinen M.
Published: July 2023

We have measured the effect of 445 nm, high power diode laser, directed on
the cathode of a SNICS ion source on the extracted beam currents of Cl-, Br- and I- ion
beams. Beam current enhancement factors up to 9 were observed in Cs-depleted operation mode of the
ion source. The photo-assisted enhancement is shown to scale with the laser power and depend
strongly on the neutral Cs flux into the ion source. The effect of the laser diminishes with
increasing Cs oven temperature. We present a qualitative model, supported by cathode current
measurement, arguing that photoelectron emission and Cs coverage of the cathode surface could
explain the observations.
Prediction of supernova neutrino signals by detectors and its future challenges
Authors: Gaba R. , Jaydip S. , Bhatnagar V. , Jyotsna S.
Published: July 2023

Supernova neutrinos produced during a core collapse of a massive star, carries 99% of the energy produced during the violent phenomenon. These neutrinos are weakly interacting massive particles and can provide useful information for both particle physics (neutrino oscillations parameters) and astrophysics (explosion mechanism). This information can be used to explore physics beyond the standard model. Neutrinos escape from the supernova core hours before the light, so a neutrino signal providing information about supernova direction can enable early observation. The current generation of detectors, like, Super-Kamiokande (Super-K), Large Volume Detector (LVD), Borexino, Kamioka Liquid Scintillator Antineutrino Detector (KamLAND), and IceCube, as well as HALO, Daya Bay(reactor neutrino experiment) and NuMI Off-Axis νe
Appearance experiment (NOvA), have the ability to detect only a few orders of magnitude of events and the next generation experiment like, Hyper-Kamiokande (Hyper-K), Deep Underground Neutrino Experiment (DUNE), and Jiangmen Underground Neutrino Observatory (JUNO) will have yet another order of magnitude in reach, as well as richer flavor sensitivity. This work will present a Monte Carlo based study using the SNOwGLoBES [1] package, which is used to estimate the event rate using folded fluxes, cross-sections, and detector smearing to determine mean expected neutrino interaction signals in multiple current and future detectors. A study is carried out for the calculation of core-collapse neutrino event rates in realistic detectors for different flux models, effects of different parameters on flux and its variation with time.
GRAVEL unfolding of gamma-ray spectra of CeBr3 detectors and related uncertainties
Authors: Dombrowski H.
Published: July 2023

Unfolded spectra are needed for the application of some
spectrum analysis methods. Frequently, iterative deconvolution
methods are used, especially if the spectra have a high
resolution. However, the uncertainties on the obtained results are
difficult to judge. In general, the user of an unfolding code gets
no information on the influence of chosen parameters, especially the
choice of the first estimate of the unfolded spectrum. General
studies regarding the uncertainties of unfolding algorithms are
difficult to perform, if not impossible, and therefore not
available. In this work, uncertainties of the results on the
iterative GRAVEL algorithm, which is based on SAND II, are closely
investigated by using medium resolution spectra recorded by using a
CeBr3 detector. Relevant parameters are varied systematically
to gain some information on the associated uncertainties on the
basis of examples. The uncertainty budget of the calculation of
total fluences and doses of unfolded spectra is compared with the
uncertainty budget of the results obtained by applying the
conversion method. The results allow, at least, the estimation of
the magnitude of typical uncertainties.
A mathematical model to identify the output variations of TrueBeam linear accelerators using Machine Performance Check evaluations
Authors: Borzì G.R. , Bonanno E. , Cavalli N. , Pace M. , Zirone L. , D'Anna A. , Stella G. , Marino C.
Published: July 2023

The aim of this work is to find an effective mathematical model to identify the output variations of TrueBeam (Varian Medical Systems, Palo Alto, CA, U.S.A.) linear accelerators (Linacs), using the daily output measurements performed with Machine Performance Check (MPC) tool. All daily output data, measured with MPC from July 2020 to October 2021, were exported and plotted for all energies investigated. After identifying the dates of dose calibration, the measurement period was divided into four and three sub-periods for photon and electron beams, respectively, common to the three Linacs; straight lines were applied to the data and slopes were analysed. Finally, all the output data were merged and a parameters optimisation process was performed that minimised the differences between output values measured by MPC and output values calculated by model. The output of Linacs under examination showed an increase for all photon and electron energies in agreement with the literature findings. MPC output trends were well represented by means of a linear mathematical model and the angular coefficients of the regression lines characterized the rate of daily output increase. The optimisation of the model provided an optimised angular coefficient for photon (0.0126% per day) and electron (0.0128% per day) beams. In this study, linear regression analysis is used to identify the TrueBeam output drift. The proposed model fitting daily MPC output data allows to define the right timing for preventive beams calibrations offering a tool to improve dose control.
Monte Carlo simulation of a high-efficacy composite material: feasibility for neutron and gamma ray shielding of Small Modular Reactor (SMR) facilities
Authors: Mukherjee B.
Published: July 2023

Secondary neutrons with energy distribution similar to that of a Small Modular Reactor
(SMR) was generated by bombarding a water target with 10 MeV proton beam from a Cyclotron and
analyzed using Monte Carlo (MC) technique. Transmission of neutrons (SMR-Analogue) through a batch
of spheres (r = 20 cm) made of a composite of Lead (PB), Boron Carbide (BC) and Polyethylene (PL)
granules of varying volume concentrations was investigated. An optimized blend of 50%(vol) PB,
2%(vol) BC and 48%(vol) PL: (50PB2BC48PL) giving the lowest neutron transmission factor was
evaluated. The tenth value layer thickness (TVLT) relevant to SMR neutrons in the optimized
composite and in ordinary concrete was calculated to be 5.6 cm and 25.4 cm respectively. The high
(50% vol) Lead content guaranteed a high attenuation of gamma rays co-produced by neutron
activation of reactor cooling water. Feasibility of the high-efficacy optimized compact composite
in radiological shielding of SMR is envisaged.
Injectable, self-healing poly(amino acid)-hydrogel based on phenylboronate ester bond for osteochondral tissue engineering
Authors: Li Guifei , Shi Zhen , Zong Hongjie , Zhang Kunxi , Yan Shifeng , Yin Jingbo
Published: July 2023

A new generation of osteochondral integrated scaffolds is needed for articular osteochondral regeneration, which can not only facilitate the accurate construction of osteochondral scaffolds in a minimally invasive manner but also firmly combine the subchondral bone layer and cartilage layer. Herein, an osteochondral integrated hydrogel scaffold was constructed by the poly(L-glutamic acid) (PLGA) based self-healing hydrogels with phenylboronate ester (PBE) as the dynamic cross-linking. The bone layer self-healing hydrogel (hydrogel O-S) was prepared by physically blending nanohydroxyapatite into the self-healing hydrogel PLGA-PBE-S, which was fabricated by 3-aminophenylboronic acid/glycidyl methacrylate-modified PLGA (PLGA-GMA-PBA) and 3-amino-1,2-propanediol/N-(2-aminoethyl) acrylamide-modified PLGA (PLGA-ADE-AP). The cartilage layer self-healing hydrogel (hydrogel C-S) was prepared by PLGA-GMA-APBA and glucosamine- modified PLGA-ADE-AP (PLGA-ADE-AP-G). Excellent injectability and self-healing profiles of hydrogel O-S and C-S were observed, the self-healing efficiencies were 97.02% ± 1.06% and 99.06% ± 0.57%, respectively. Based on the injectability and spontaneous healing on the interfaces of hydrogel O-S and C-S, the osteochondral hydrogel (hydrogel OC) was conveniently constructed in a minimally invasive manner. In addition, in situ photocrosslinking was used to enhance the mechanical strength and stability of the osteochondral hydrogel. The osteochondral hydrogels exhibited good biodegradability and biocompatibility. The osteogenic differentiation genes BMP-2, ALPL, BGLAP and COL I of adipose-derived stem cells (ASCs) in the bone layer of the osteochondral hydrogel were significantly expressed, and the chondrogenic differentiation genes SOX9, aggrecan and COL II of ASCs in the cartilage layer of the osteochondral hydrogel were obviously upregulated after 14 d of induction. The osteochondral hydrogels could effectively promote repair of osteochondral defects after 3 months post-surgery.
Coordinating the electric vehicle transition and electricity grid decarbonization in the U.S. is not essential to achieving substantial long-term carbon dioxide emissions reductions
Authors: Leard Benjamin , Greene David
Published: July 2023

How quickly the US can decarbonize light-duty vehicle (LDV) transportation depends on the rates of change of electric vehicle (EV) sales, stock turnover, and grid decarbonization. We build a stock turnover model to assess how sensitive achieving 2050 LDV decarbonization targets is to these rates. We estimate carbon dioxide (CO2) reductions of 70%–85% by 2050, including emissions from vehicles and upstream electricity generation, provided that new vehicle sales transition to 100% EVs and substantial grid decarbonization are accomplished by 2050. This result is robust to continuation of long-term trends of increasing vehicle longevity, and to whether the timing of EV sales growth and grid decarbonization are coordinated. If the two key goals are met, the annual contribution of EV electricity use to CO2 emissions will be small over the entire period.
Is land use producing robust signals in future projections from Earth system models, all else being equal?
Authors: Tebaldi Claudia , Wehner Michael , Leung Ruby , Lawrence David
Published: July 2023

We use six Earth system models (ESMs) run under SSP3-7.0, a scenario characterized by a relatively large land use change (LUC) over the 21st century, and under a variant of the same scenario where a significantly different pattern of LUC, taken from SSP1-2.6, was used, all else being equal. Our goal is to identify changes in climate extremes between the two scenarios that are statistically significant and robust across the ESMs. The motivation for this study is to test a long-held assumption of the shared socio-economic pathway-representative concentration pathway (SSP-RCP) scenario framework: that the signal from LUC can be safely disregarded when pairing different SSPs to the compatible RCPs, where compatibility only considers global radiative forcing, predominantly determined by well-mixed greenhouse gasses emissions. We analyze extremes of daily minimum and maximum temperatures and precipitation, after fitting non-stationary generalized extreme value distributions in a way that borrows strength along the length of the simulation (2015–2100) and across initial condition ensembles. We consider changes in the 20 year return levels (RL20s) of these metrics by 2100, and focus on eight locations where LUC is large within each scenario, and strongly differs between scenarios, averaging the RL20s over a neighborhood characterized by the same LUC to enhance the signal to noise. We find that precipitation extremes do not show significant differences attributable to LUC differences. For temperature extremes (cold and hot) results are mixed, with some location-index combination showing significant results for some of the ESMs but not all, and not many coherent changes appearing for indices across regions, or regions across indices. These ESMs are representative of what is typically adopted as the source of climate information for impact studies, when the SSP-RCP framework is put to use. Overall, our analysis suggests that the hypothesis to pair SSPs to RCPs in a flexible fashion is overall defensible. However, the appearance of some coherence in a few locations and for some indices invites further investigation.
Evaluating net life-cycle greenhouse gas emissions intensities from gas and coal at varying methane leakage rates
Authors: Gordon Deborah , Reuland Frances , Jacob Daniel J , Worden John R , Shindell Drew , Dyson Mark
Published: July 2023

The net climate impact of gas and coal life-cycle emissions are highly dependent on methane leakage. Every molecule of methane leaked alters the climate advantage because methane warms the planet significantly more than CO2 over its decade-long lifetime. We find that global gas systems that leak over 4.7% of their methane (when considering a 20-year timeframe) or 7.6% (when considering a 100 year timeframe) are on par with life-cycle coal emissions from methane leaking coal mines. The net climate impact from coal is also influenced by SO2 emissions, which react to form sulfate aerosols that mask warming. We run scenarios that combine varying methane leakage rates from coal and gas with low to high SO2 emissions based on coal sulfur content, flue gas scrubber efficiency, and sulfate aerosol global warming potentials. The methane and SO2 co-emitted with CO2 alter the emissions parity between gas and coal. We estimate that a gas system leakage rate as low as 0.2% is on par with coal, assuming 1.5% sulfur coal that is scrubbed at a 90% efficiency with no coal mine methane when considering climate effects over a 20 year timeframe. Recent aerial measurement surveys of US oil and gas production basins find wide-ranging natural gas leak rates 0.65% to 66.2%, with similar leakage rates detected worldwide. These numerous super-emitting gas systems being detected globally underscore the need to accelerate methane emissions detection, accounting, and management practices to certify that gas assets are less emissions intensive than coal.
Tetrahedron genuine entanglement measure of four-qubit systems
Authors: Guo Meng-Li , Jin Zhi-Xiang , Li Bo , Fei Shao-Ming
Published: July 2023

Quantifying genuine entanglement is a key task in quantum information theory. We study the quantification of genuine multipartite entanglement for four-qubit systems. Based on the concurrence of nine different classes of four-qubit states, with each class being closed under stochastic local operation and classical communication, we construct a concurrence tetrahedron. Proper genuine four-qubit entanglement measure is presented by using the volume of the concurrence tetrahedron. For non genuine entangled pure states, the four-qubit entanglement measure classifies the bi-separable entanglement. We show that the concurrence tetrahedron based measure of genuine four-qubit entanglement is not equivalent to the genuine four-partite entanglement concurrence. We illustrate the advantages of the concurrence tetrahedron by detailed examples.
Public practice on the unused pharmaceutical waste and the effect on surface water
Authors: Khairunniza N , Aliyu M K
Published: July 2023

Pharmaceutical waste is a waste that kept piling up by the days due to the increasing production of it. This issue leads to the detection of pharmaceutical waste residue in the water surface based on the previous studies that were conducted. This study was conducted to know the public practice on how they dispose of their unused pharmaceutical waste and help them to know the effect of that action to the water. A questionnaire was distributed to the target respondents to know their practice on how they dispose of the waste and the collected data were analysed to evaluate the public awareness about the effect of pharmaceutical waste to surface water. About 60 percent of the respondents knew that disposing of pharmaceutical waste can contaminate the surface water, yet there is still 24 percent of them that still dispose it by flushing it down the toilet. According to the study, the residue of the pharmaceutical waste can still be detected in drinking water even after water treatment. Antibiotic resistance may result from continued consumption even when there are no specific studies to demonstrate a direct connection to the water supply. It is also evident from the study that the respondents lacked sufficient knowledge about the proper and safe methods for disposing of unwanted pharmaceutical waste.
Analysis of hydrodynamic forces on freestanding risers with buoyancy cans
Authors: Earnest Praise , Al-Yacouby Ahmad Mahamad , Jarghouyeh Ehsan NikBakht
Published: July 2023

Free-standing hybrid risers are vertical slender steel pipes that are commonly used in the oil and gas industry. These slender structures are subjected to complex hydrodynamic loads that results in fatigue damage. The tidal forces that develop on Freestanding Risers (FSR) with buoyancy cans (BC) because of varying outer pipe dimensions are investigated in this work. The study considered riser diameters of 0.2, 0.3, 0.5 and 0.6 meters as well as buoyancy can diameters ranging from 2, 3, 5 and 6 meters. The Morison equation was used in this study to investigate the wave hydrodynamic forces. Separate assessments of the lift force are also carried out consider a water depth (d) of 30 m. The findings reveal that the pipe diameter, wave heights and the wave periods have significant impacts on the hydrodynamic forces on the riser.
Assessment of river water quality improvement due to riverbank filtration (RBF) mechanism
Authors: Baharudin F , Zailani I , Hamzah N , Mohd Zaki Z Z , Mohamad I N
Published: July 2023

Riverbank filtration (RBF) is a natural process where river water is induced to flow through riverbed soils to pumping wells located on the banks. It is a well-established and proven natural water treatment technology by having a series of physical and chemical processes during subsurface passage. This paper aims at the measurement of physical and chemical characteristics of river water and groundwater from riverbank filtration wells at Kg. Jenderam Hilir, Selangor and to assess the effectiveness of riverbank filtration through Water Quality Index (WQI) for both river water and groundwater. The riverbank filtration is able to improve quality of water such as reducing the turbidity to 0 NTU, Chemical Oxygen Demand (COD) to 3.67 mg/l, Suspended Solids (SS) to 6.33 mg/l and several other contents that existed in the river. In addition, the effectiveness of RBF is also proven based on the improvement of Water Quality Index (WQI) for Langat river from Class IV to Class III.
Evaluation lead removal kinetics modelling of adsorption by using composite of Chitosan and Ceramic waste
Authors: Bakar Siti Asmah , Geedi Hussein Saed , Khamidun Mohd Hairul , Mohamed Radin Maya Saphira Radin , Daud Mohammad Faizal Che , Md Ali Umi Fazara
Published: July 2023

This study focuses on understanding the Pb adsorption kinetics from greywater using a composite of chitosan and ceramic waste (CCCW), which is suitable for preserving water quality. For ease and general application, a kinetic model with a simple expression and a manageable small set of parameters that nevertheless provides a fair adsorption description in the equilibrium state is still critical. Although some current kinetic models, such as the pseudo-second-order type, meet these conditions, their performance is still questionable, especially when applied to a variety of experimental data. Batch adsorption experiments were carried out with the predetermined value of the operational parameter such as adsorbent dosage, contact time, and shaking speed. Kinetic models such as pseudo-first order, pseudo-second order, intraparticle diffusion kinetic model, Avrami model, and the Bangham model were used in this study to understand the kinetics of removal of lead from greywater. The efficacy results of adsorbent’s dose in lead removal process with increasing adsorption capacity with contact time from 0.0014 to 0.00277 mg/g, the removal efficiency increases from 45.90 to 90.83%. The most significant contribution of this work is an understanding of the optimal kinetics model that can describe the behaviour of lead adsorption on CCCW. Five models for the adsorption of Pb2+ have been identified to clarify the kinetics models’ usefulness in accuracy based on rank order. This study may provide insight into understanding the ability and usability of the appropriate model in kinetics adsorption.
Active cooling system for solar panels with silver nanofluid and water
Authors: Deivakumaran S , Chua Y L , Koh Y Y
Published: July 2023

Solar panel is used to harvest solar energy through the photovoltaic panels to generate electricity. Due to the different intensity of the sun, the panel may be getting overheated during the operation which affect the performance. The research was conducted to analyse the efficiency of liquid immersion cooling technique with water, measure the differences of water and nanofluids under the liquid immersion technique, and determine the efficiency increase of the cooling system with additional cooling. The apparatus was set up to test the cooling system performance throughout the most active part of the day with sunlight. The collected data has shown an increase in the power efficiency of 12.66% in favour of silver nanofluid compared to water when the cooling system is attached with additional cooling capabilities. However, without the additional cooling capabilities, the difference in power output between silver nanofluid and water shows around 2.42% in favour of silver nanofluid. The use of nanofluid in this experiment indicates a noticeable increase in power efficiency through the ability to keep the panel better cooled throughout the day. This allows nanofluids to be used as a cooling fluid to remove heat form the solar panel.
Removal of Copper, Chromium, and Nickel Ions from aqueous solution by using different pre-treated orange peel
Authors: Low Wen-Pei , Lim Wen-Jie , Lee Hoong-Pin , Rahman Nurharniza Abdul
Published: July 2023

In Malaysia, water pollution due to the various heavy metal contaminants has become a serious issue that needs to be concerned. Among various water treatment methods, the adsorption method has been considered one of the most efficient wastewater treatment techniques. This study was done to find out the adsorption capacity of orange peel (OP) by different pre-treatment in removing copper, chromium, and nickel ion from aqueous. OP powder was divided into three portions, which were untreated OP, pretreated with sodium hydroxide (NaOH) OP, and detergent OP respectively. Each chemical solution that contains copper, chromium and nickel respectively was tested by these three adsorbents. From the experiment, NaOH pretreated OP was found highest performance in removing 85.67% of nickel and 81.55% of copper. While the untreated OP was good in removing 91.2% of chromium. The untreated OP for nickel ions and copper ions, Detergent treated OP for nickel ions and chromium ions were best fitted to Langmuir Isotherm, while untreated OP for chromium ions, detergent treated OP for copper ions and NaOH treated OP for all selected metal ions were best fitted to Freundlich Isotherm. In short, OP can be considered a very good adsorbent choice due to its good adsorption capacity, environment-friendly nature and low-cost characteristics.
Evaporation rate for covered and uncovered condition case study: UiTM Shah Alam
Authors: Daud Intan Zulaikha , Zaki Zaizatul Zafflina Mohd , Mohammad Irma Noorazurah , Baharudin Fauzi
Published: July 2023

High development, urbanization, and industrial activity in urban areas contribute to greenhouse gases emission that increases ambient temperatures. These phenomena influence the hydrological cycle as it speeds up the rate of evaporation in water storage. Sufficient water resource is essential as it helps to grow social and economic activities in a country. The study developed three aluminium evaporation pan models with 225 mm diameter and 80 mm width to measure the evaporation in UiTM Shah Alam. Each pan was covered using ping pong balls as a floating cover with a different percentage of coverage. The percentage of coverage used in the pan models is 0% uncovered, 46.08% covered, and 92.16% covered condition. The observation lasted 12 hours, from 8.00 am to 8.00 pm. The 0% uncovered condition had the highest evaporation with 6 mm, followed by the 46.08% covered and 92.16% covered conditions with 3 mm and 2 mm, respectively. Next, the influence of temperature on the evaporation rate in the three conditions was also analysed. The provided floating cover reduces the effect of temperature on the rate of evaporation in urban area.
A Study on household food waste management and composting practice
Authors: Amiruddin N N H N , Rozamri N A , Baharudin F , Mohamad I N
Published: July 2023

Food waste had been such an alarming issue, not only in Malaysia, but throughout the world. Composting is an environmentally friendly way to reduce food waste by using a less costly and less time of the system. Composting is considered the most common method used to compost by having organic materials and water only. This study aims to identify the level of awareness among respondents about food waste composting and to assess the effectiveness of composting method at home basis. An online survey and experimental work were conducted. The online survey was conducted among the population in Taman Seri Tanjung, Kota Bharu, Kelantan. Quantitative analysis from the online survey showed that respondents had awareness of the advantages of composting. While, 29-day observation during food waste composting show pH and temperature were recorded as in the range of 29°C to 40°C and 5 to 7 respectively. The result from this study shows promising findings on the effectiveness of the composting method. The findings from this study will enhance the understanding and awareness of the public on the importance of composting at the household level.
Flood modelling at Bandar Batu Pahat, Johor using HEC-RAS software
Authors: Razi M A M , Adnan M S , Abustan M S H , Uma M H A , Anuar N D , Jamal M H
Published: July 2023

Flood catastrophe continuously hit Malaysia through monsoonal flood and flash flood as well posing threat towards people, infrastructure and environment. Batu Pahat is among the district in Johor affected by flood disaster for almost every year. This study conducted to determine the hydraulic and hydrological characteristic and the ability of drainage system in Parit Besar and Jalan Pontian-Batu Pahat catchment area at Batu Pahat using HEC-RAS software. Through HEC-RAS, floodplain map was also produced to access the overview of potential floodplain areas. Survey data, geometric data and flow data were computed in HEC-RAS to produce drainage flow and cross-sectional area along the catchment area. Four (4) flow rates of 0.05284, 0.05894, 0.06910 and 0.07113 (m3/s) were utilized to identify the drainage ability to accommodate additional water. Several stations in Parit Besar catchment cannot accommodate the runoff with the minimum flow rate of 0.05284 (m3/s). Meanwhile, Jalan Pontian-Batu Pahat catchment cannot accommodate flow rates of 0.06910 and 0.07113 (m3/s). This is due to the catchment area has low elevation and insufficient drainage system. From the results, floodplain areas were identified. Modification of drainage cross-section was proposed to reduce the floodplain areas. This study is vital for better understanding of flooding and help the authorities to produce better flood management plan.
Removal of copper and zinc in metal working fluid using coconut composite filter media
Authors: Aziz A F , Akbar N A , Ismail B N , Said M S , Yusoff M S , Adnan M I
Published: July 2023

Metal working fluid industry is the major contributing sources of heavy metals. Their multiple industrial, domestic, and technological applications have led to their wide distribution in the environment, raising concerns over their potential effects on human health and the environment. Filtration technology is widely used to remove contaminants such as heavy metals because it is a low-cost wastewater treatment device that uses physical methods that are simple and effective. In this study, coconut composite activated carbon (CCAC) filter media has been explored for its adsorption abilities towards copper and zinc solutions from metal working fluids. The characteristic of CCAC was investigated using XRF analyser, SEM and FTIR analysis. This study described the performance of fixed-bed column filtration by using CCAC as the filter media under the effect of various bed heights (10,30,50 cm) and initial concentration of copper and zinc (10 and 20 mg/L) to assess the breakthrough curve. The results show that the CCAC surface is not smooth and porous, with many channels. It is connected to hydrogen linked, O-H and contains the highest value composition in MgCO3 and CaCO3, which enhances metal precipitation removal of heavy metals. From the fixed-bed column study, the column with an initial copper and zinc concentration of 10mg/L and a bed height of 50 cm performed well in removing copper and zinc from synthetic copper and zinc solutions. The breakthrough and exhaustion times were less than 30 minutes and 3660 minutes for copper and zinc were less than 30 minutes and 3420 minutes respectively. The longer the lifespan of filter media, the better the filter media for heavy metal treatment. In conclusion, CCAC filter media was used as an alternative to the existing wastewater treatment process to remove copper and zinc from metal working fluids. It also can be applied in the current filtration system, especially for industrial Wastewater Treatment Plant (WWTP).