bluuebunny/crossref_metadata_2025 huggingface dataset:
Vector wave dark matter and terrestrial quantum sensors
Authors: Amaral Dorian W.P. , Jain Mudit , Amin Mustafa A. , Tunnell Christopher
Published: June 2024

(Ultra)light spin-1 particles — dark photons — can constitute all of dark matter (DM) and have beyond Standard Model couplings. This can lead to a coherent, oscillatory signature in terrestrial detectors that depends on the coupling strength. We provide a signal analysis and statistical framework for inferring the properties of such DM by taking into account (i) the stochastic and (ii) the vector nature of the underlying field, along with (iii) the effects due to the Earth's rotation. Owing to equipartition, on time scales shorter than the coherence time the DM field vector typically traces out a fixed ellipse. Taking this ellipse and the rotation of the Earth into account, we highlight a distinctive three-peak signal in Fourier space that can be used to constrain DM coupling strengths. Accounting for all three peaks, we derive latitude-independent constraints on such DM couplings, unlike those stemming from single-peak studies. We apply our framework to the search for ultralightB - LDM using optomechanical sensors, demonstrating the ability to delve into previously unprobed regions of this DM candidate's parameter space.
Identifying Three New AGNs among Fermi Unidentified Gigaelectronvolt Sources
Authors: Ji Shun-Hao , Wang Zhong-Xiang , Huang Qiang-Meng , Yang Ruo-Heng
Published: June 2024

We report our identification of three gigaelectronvolt γ-ray sources, 4FGL J0502.6+0036, 4FGL J1055.9+6507, and 4FGL J1708.2+5519, as Active Galactic Nuclei (AGNs). They are listed in the latest Fermi-Large Area Telescope source catalog as unidentified ones. We find that the sources all showed γ-ray flux variations in recent years. Using different survey catalogs, we are able to find a radio source within the error circle of each source’s position. Further analysis of optical sources in the fields allows us to determine the optical counterparts, which showed similar variation patterns to those seen in γ-rays. The optical counterparts have reported redshifts of 0.6, 1.5, and 2.3, respectively, estimated from photometric measurements. In addition, we also obtain an X-ray spectrum of 4FGL J0502.6+0036 and a flux upper limit on the X-ray emission of 4FGL J1055.9+6507 by analyzing the archival data. The broadband spectral energy distributions of the three sources from radio to γ-rays are constructed. Comparing mainly the γ-ray properties of the three sources with those of different sub-classes of AGNs, we tentatively identify them as blazars. Followup optical spectroscopy is highly warranted for obtaining their spectral features and thus verifying the identification.
Implementation of Allan Standard Deviation Technique in Stability Analysis of 4C31.61 Quasar Position
Authors: Syafaq Muthmaina Jessica , Nurul Huda Ibnu , Satya Palupi Dwi
Published: June 2024

The International Celestial Reference Frame (ICRF) plays an important role in astronomy and geodesy. The realization of ICRF is based on the position of thousands of quasars observed using the Very-Long Baseline Interferometry (VLBI) technique. Better quality of ICRF is achieved when the position of the quasars is stable. In this study, we aim to analyze the stability of one of the quasars in ICRF called 4C31.61 (2201+315). We performed VLBI data analysis by using Vienna VLBI and Satellite Software (VieVS) to get the position of the quasar. We also used the data of the quasar’s position from the Paris Observatory Geodetic VLBI Center. We examined the stability of the quasar position by using the Allan standard deviation technique. We found that the quasar 4C31.61 (2201+315) has a stable position with the dominance of white noise across the majority of time scales.
Stability Analysis of Modified Circular Restricted Three Body Problem by Lyapunov Exponent Indicators
Authors: Nugraha A M , Nurul Huda I , Kuntjoro Y D , Haz H R S , Azhar I K , Abdurrazaq A
Published: June 2024

The circular restricted three body problem (CRTBP) is a well-known problem that has a very important contribution to understand the dynamics of celestial objects, including the binary stars and planetary system. In this study, we extend the classical version of CRTBP by assuming both primaries emit radiation and have oblate shape. We also consider the potential from a disk like structure that surrounds this three-body system. The stability of the infinitesimal body is investigated by using Lyapunov Exponent Indicators (LEI). First, we have done a numerical survey by testing several initial locations of the infinitesimal body that have chaotic or regular orbital behaviour. Second, we estimated the stability of triangular equilibrium points and show that the equilibrium points are conditionally stable with respect to the critical mass parameter (μc
). We found that the determined μc
from LEI method match μc
from linear stability analysis.
Model of Close Orbit Dynamics Around Asteroid (338) Budrosa
Authors: Haz H. R. S. , Nurul Huda I. , Nugraha A. M. , Azhar I. K. , Abdurrazzaq A.
Published: June 2024

In this paper, we revisited the model of gravitational potential generated by irregular shapes. A finite straight segment model was used to investigate the motion of particles around a massive straight segment of length 2l, mass M, and uniformly rotates with angular velocity ω. We extended this model by converting it to the cylindrical coordinate and applied this model to the asteroid (338) Budrosa. We obtained the position of equilibrium points in this system. We also estimate the zero-velocity curve and determine the Poincare map and its periodic orbit around equilibrium points.
Promoting Awareness of Light Pollution Through Collaborative University Courses
Authors: Vierdayanti K. , Kunjaya C. , Herdiwijaya D. , Ahmad H. A. , Aprilia  , Wulandari H. , Simatupang F. M.
Published: June 2024

Light pollution contributes to sustainability issues in urban areas. Raising awareness regarding light pollution and its effects becomes a necessity to increase individual contribution in reducing light pollution. We chose light pollution as a topic for collaborative courses in our university to facilitate collaboration between courses’ participants in promoting awareness regarding light pollution to the public. The participants were required to work in groups to explore light pollution issues. They also collected light pollution data using a citizen science project. They were also required to design visual media and plan a public event to promote public awareness. Students’ surveys were collected to assess the benefits of this collaborative project and as part of evaluation tools. The impact of the project to the society will be measured in the future since more data are needed.
Simulation of ultrasonic characterization for the microstructure of titanium alloy
Authors: Zhao Yang , Peng Zhenghan , Kong Shuyuan , Yang Pinghua , Wang Xiao
Published: June 2024

This paper describes a method of simulating the ultrasonic longitudinal wave (P-wave) propagation in titanium alloy. The two-dimensional geometric model of polycrystalline titanium alloy is established using the Voronoi algorithm. Then, the model was imported into COMSOL software for grid division and parameter setting. The continuous observation of P-wave propagation was realized after adding the physical field of sound pressure and the boundary condition. Further, the first and second transmitted P-wave obtained the ultrasonic attenuation spectrum (UAS). The inverse method determines the average grain size (AGS) by fitting the UAS. It was found that the AGS

D
¯

=
47.5

μm of the titanium alloy was obtained by the least square fitting method, and the relative error between the inverse value of AGS and the set value in the model approached 5%.
Preparation and performance of iron-based amorphous strip/AZ31 Mg alloy laminated composites
Authors: Zhou Bingwen , Wang Wenjiao , Jing Dong , Qi Ying , Meng Linggang , Ya Bin , Zhang Xingguo
Published: June 2024

In this paper, the iron-based amorphous/AZ31 microlaminated composites with multilayer structures were successfully prepared by using the vacuum hot-pressing method. The microstructure and chemical element distribution were analyzed, and the mechanical properties and microhardness were tested. Research findings revealed that a thin iron-aluminum intermetallic compound layer was formed between the iron-based amorphous alloy and AZ31, and the interlayers were tightly bonded. The microhardness of the amorphous after the hot-pressing reaction reached 1590 HV and there was a hardness gradient between the AZ31 layer and the amorphous layer. The bending strength reached 516 MPa after hot-pressing temperature at 520°C and the impact toughness was about 6 J/cm2. The fracture behavior was a combination of brittle fracture and ductile fracture. The microstructure and the properties of the laminated composites can be designed by adjusting the process according to the performance needs, which opens up broad prospects for the wide application of amorphous alloys.
A fast-response SMA artificial muscle integrated with hydrogel and thermoelectric materials
Authors: Zhang Quan , Chen Hao , Yin Xingfeng , Zhou Liping , Zhou Wangjie , Li Long , Yi Sicheng
Published: June 2024

Shape memory alloy (SMA) is widely used in the field of soft robots due to its high energy density and favorable load-to-weight ratio. However, the cooling time of SMA wire in the soft matrix is relatively long, limiting its response velocity. In this study, we develop a fast-response SMA artificial muscle (FSAM), which accelerates the cooling rate of SMA wire through the active heat absorption of the thermoelectric module and the evaporation/dehydration of hydrogel. The hydrogel also facilitates the heat dissipation of the thermoelectric module. Additionally, COMSOL is utilized to investigate the thermal characteristics of the SMA wire under different conditions. The simulation results demonstrate that the cooling rate of the SMA wire increases significantly with the proposed heat dissipation scheme.
Unmanned lunar exploration bionic mesh wheel design and performance study
Authors: Zhao Liangliang , Zhang Rui , Zhang Hua , Ma Jia , Du Yupei , Hu Zhenyu
Published: June 2024

Addressing the limitations of traditional lunar exploration mesh wheels in improving the traction performance of unmanned lunar rovers through conventional optimization, this study introduces a novel bionic mesh wheel design inspired by the characteristics of ostrich toes. A comparative wheel design is also developed for control experiments. Discrete element simulations are conducted for both the bionic and comparative wheels. Comparative analysis of their macroscopic simulation data reveals that the bionic wheel outperforms the comparative wheel in terms of traction performance. Furthermore, the bionic wheel exhibits higher traction efficiency and energy savings at lower slip ratios. The feasibility of the proposed design is validated through soil trough experiments, providing evidence for its practical viability in enhancing the traction capabilities of unmanned lunar exploration vehicles.
Preparation of silicon oxycarbide ceramic fiber membranes for thermal insulation
Authors: Shi Yu , Cao Lei , Zhang Zhuoqing , Hua Lingwen , Zhang Xing
Published: June 2024

Lightweight thermal insulation materials are of critical importance for vehicle safety within the aerospace industry. In this study, polysiloxane fiber membranes were prepared by electrospinning, which was further pyrolyzed at 1000°C for an hour to obtain silicon oxycarbide (SiOC) ceramic fiber membranes, which contained SiOC fibers with the diameters of 1.03 ± 0.04 μm. In addition, the back temperature of SiOC ceramic fiber membranes with a thickness of 1 mm reached only 375°C after being subjected to 1100°C for 120 seconds, showing excellent thermal insulation capability. Thus, the SiOC ceramic fiber membranes have great potential applications for thermal insulation in the aerospace field.
Research on corrosion wear behavior of connecting bearings made of different steels in suspension bridge suspension system
Authors: Wang Shiyuan
Published: June 2024

This study aims to investigate the characteristics of corrosion wear behavior of different steel connecting bearings in suspension bridge suspension systems. The corrosion and wear of Q195, Q215, and BC550 steel in the suspension bridge suspension system environment were studied through experimental analysis. Research has found that different steel connecting bearings exhibit different corrosion and wear behaviors in suspension bridge environments. The research results indicate that BC550 steel bearings exhibit strong corrosion resistance. Q195, Q215, and BC550 steels exhibit good wear and corrosion resistance in neutral and alkaline media. In acidic media, the friction and wear mass loss of BC550 steel is the smallest.
A novel RDL structure of improving high-frequency transmission and reliability of FOWLP
Authors: Dai Zehui , Zhu Guanqun
Published: June 2024

In this paper, an effective structure RDL-GR is proposed to improve the electrical and reliability of the fan-out wafer package (FOWLP) with the addition of a graphene layer on the surface of the Redistribution Layer (RDL), including suppression and modulation of signal delay and crosstalk noise. A modified circuit model is formulated to evaluate the impact of RDL-GR on the transmission characteristics at high frequencies. Subsequently, the validity of the model is verified by utilizing the HFSS. Found on the circuit at high frequencies, the transmission characteristics of the RDL-GR compared to the traditional RDL structure (Tr-RDL) have better performance. At the same time, measurement by Vector Network Analyser (VNA) is carried out and results prove that the maximum error values of S11 and S21 are 1.81% and 1.47%, and make a strong case that S-parameters of RDL-GR for simulation using HFSS are reliable.
Research on surface strengthening of self-propelled cotton picker picking ingot based on thermal coating
Authors: Yang Zhixuan , Sun Wenlei , Jiang Yiming , Tang Wei , Wang Lihong
Published: June 2024

Xinjiang is the largest cotton-producing region in China, and mechanized cotton picking can reduce labor costs and improve production efficiency. The function of the spindle of the key parts of the cotton picker has a great influence on the picking rate and net rate of cotton. The wear of cotton picking will seriously hinder the process of cotton picking. Molybdenum disulfide, as a coating, can give it excellent wear and corrosion resistance. By analyzing the picking mechanism and failure mode of the spindle, carburizing, tempering heat treatment (quenching + tempering) and hot coating tests were carried out to realize the surface strengthening of the spindle. The surface properties of spindle specimens without superheat treatment and after carburizing and tempering heat treatment and hot coating molybdenum disulfide were compared. Conclusion: After heat treatment and hot coating molybdenum disulfide, the surface hardness and wear resistance of ingot-picking specimens are significantly improved compared with those without thermal treatment.
Energy efficient homes for rodent control across cityscapes
Authors: Gadsden Gabriel I , Ferraro Kristy M , Harris Nyeema C
Published: June 2024

Cities spend millions of dollars on rodent mitigation to reduce public health risks. Despite these efforts, infestations remain high and distressing. Rodents thrive in the built environment in part due to reduced natural predators and their exploitation of garbage. Though sanitation and greenspace are important factors in rodent mitigation, more complex governance and actions are needed. Urban rodents are dynamic and commensal in nature, so understanding the influence of prolific urban features, like building attributes, warrants scrutiny and additionally intersects mitigation strategies with stakeholders at a localized level. Here, we model how residential structures’ efficiency influences urban rodent populations. To do so, we created an agent-based model using characteristics of urban brown rats and their natural predator, red foxes, based on three distinct neighborhoods in Philadelphia, Pennsylvania. We varied whether retrofitting occurred and its duration as well as the percent of initial energy-efficient homes in each neighborhood. We found that initial housing conditions, retrofitting, and the duration of retrofitting all significantly reduced final rodent populations. However, retrofitting was most effective in reducing rodent populations in neighborhoods with extensive park access and low commercial activity. Additionally, across neighborhoods, single large efficiency initiatives showed greater potential for rodent reduction. Lastly, we show that the costs of large-scale retrofitting schemes are comparable to ten-year public health spending, demonstrating that retrofitting may have the potential to offset near-term costs. Our results showcase how system-view investments in integrated pest management can lead to sustained rodent pest mitigation and advance sustainable development goals, infrastructure innovation (Goal #9), reduced inequalities (Goal #10), and sustainable cities and communities (Goal #11).
Characterizing multi-pollutant emission impacts of sulfur reduction strategies from coal power plants
Authors: Wu Xinran , Holloway Tracey , Meier Paul , Edwards Morgan
Published: June 2024

Fuel combustion for electricity generation emits a mix of health- and climate-relevant air emissions, with the potential for technology or fuel switching to impact multiple emissions together. While there has been extensive research on the co-benefits of climate policies on air quality improvements, few studies have quantified the effect of air pollution controls on carbon emissions. Here we evaluate three multi-pollutant emission reduction strategies, focused on sulfur dioxide (SO2) controls in the electricity sector. Traditional ‘add-on’ pollution controls like flue gas desulfurization (FGD) reduce SO2 emissions from coal combustion but increase emissions of nitrogen oxides (NO
X
), volatile organic compounds (VOCs), fine particulate matter (PM2.5), and carbon dioxide (CO2) due to heat efficiency loss. Fuel switching from coal to natural gas and renewables potentially reduces all pollutants. We identified 135 electricity generation units (EGUs) without SO2 controls in the contiguous US in 2017 and quantified the unit-level emission changes using pollution control efficiencies, emission rates, fuel heat input, and electricity load. A cost-benefit analysis is conducted, considering pollution control costs, fuel costs, capital and operation and maintenance (O&M) costs, the monetized health benefits from avoided multi-pollutant, and the social cost of carbon as the benefit for carbon reduction. We find that add-on SO2 controls result in an average annual net benefit of $179.3 million (95% CI: $137.5-$221.0 million) per EGU, fuel switching from coal to natural gas, $432.7 million (95% CI: $366.4-$498.9 million) per EGU; and fuel switching from coal to renewable energy sources, $537.9 million (95% CI: $457.1-$618.9 million) per EGU. Our results highlight multi-pollutant emission reduction strategy as a cost-effective way to synergistically control air pollution and mitigate climate change.
Time-optimal state transfer for an open qubit
Authors: Lokutsievskiy L V , Pechen A N , Zelikin M I
Published: June 2024

Finding minimal time and establishing the structure of the corresponding optimal controls which can transfer a given initial state of a quantum system into a given target state is a key problem of quantum control. In this work, this problem is solved for a basic component of various quantum technology processes—a qubit interacting with the environment and experiencing an arbitrary time-dependent coherent driving. We rigorously derive both upper and lower estimates for the minimal steering time. Surprisingly, we discover that the optimal controls have a very special form—they consist of two impulses, at the beginning and at the end of the control period, which can be assisted by a smooth time-dependent control in between. Moreover, an important for practical applications explicit almost optimal state transfer protocol is provided which only consists of four impulses and gives an almost optimal time of motion. The results can be directly applied to a variety of experimental situations for estimation of the ultimate limits of state control for quantum technologies.
Wave climate analysis for shoreline management plan in Kelantan, Malaysia
Authors: Yusoff M A M , Al-Qadami E H H , Razi M A M , Wang M , Daud Z H , Mokhtar A , Mahamud M
Published: June 2024

Waves climate analysis is of primary concern for several purposes such as maintaining coastal structures, navigation and maritime operations, coastal management, and recreation and tourism. Therefore, understanding the wave climate of a particular region helps in making informed decisions related to coastal and maritime activities, ensuring safety, efficiency, and sustainability. In this paper, wave analysis was conducted for Kelantan State shoreline, Malaysia. The studied shoreline covers around 71 km starting from Pengkalan Kubur to Besut. 5 years data (2014 to 2019) was collected at the location of 6.3N and 102.3E. The analysis was performed under different aspects including, annual wave rose, annual percentage reoccurrence, return period analysis, and closure dept. According to the results, it was found that the predominant waves are coming from the 60 to 90 degrees North sector due to the unlimited fetch in that direction. Besides it was noticed that more than 50% of the waves have periods between 4 to 7 seconds and around 52% have wave heights of less than 1.5m. Also, it was found that the wave depth for a 100-year return period is about 2.75m. Finally, the depth of closure was calculated and found to be 7 m. The outcomes of this study can provide a better understanding of the wave climate along the Kelantan State shoreline and can be used as a reference for future coastal and maritime activities.
The efficiency removal of oil in water (OIW) by application of milliscale air bubbles
Authors: Yusof H A M , Razi M A M , Yusof M F M , Zulkifli N F M , Setiawan M I
Published: June 2024

The existing technology for separating oil in water (OIW) can bring harm to the environment, particularly to marine life. A new environmentally friendly technique has been proposed, involving the use of milliscale air bubbles. This study was conducted to determine the suitable retention time for injecting the milliscale air bubbles into the OIW. The significance of this study lies in its ability to separate OIW through a procedure that is environmentally safe and does not impact the ecosystem or marine life. The method used in the study involved mixing palm oil with water on a volumetric hydraulic bench. Retention times of 5 minutes, 15 minutes, 30 minutes, and 60 minutes were used in the study. The results indicated that separating oil in water required a substantial amount of time when utilizing milliscale air bubbles. In this study, a 60-minute retention time exhibited a significant number of separations, producing 512 bubbles compared to 44 bubbles generated in 5 minutes for 200 mL of oil. The longer the retention time, the more bubbles were produced. Overall, milliscale bubbles can effectively be used for the separation of oil in water.
Simultaneous removal of turbidity, suspended solids and chemical oxygen demand from carwash effluent using aluminium electrodes in monopolar mode electrocoagulation
Authors: Muyarip A , Aziz N A A
Published: June 2024

The growth of car wash centres across the country increases every year due to the increase in the number of vehicles needed to meet transportation demands for daily affairs. Therefore, there is a concern about releasing carwash wastewater (CWW) into the drainage system and waterways without proper treatment. This is a problem for small and medium enterprises that lack the financial budget to provide a suitable treatment system for a car wash centre. The effects of hazardous contaminant emissions can harm ecology and public health. Electrocoagulation using aluminium (Al) electrodes is expected to replace the use of chemicals in the coagulation system that will leave harmful secondary residues and be expensive in terms of cost. With that, this experimental work was conducted to investigate the effectiveness of electrocoagulation using Al electrodes to eliminate target contaminants such as turbidity, suspended solids (SS), and chemical oxygen demand (COD) from CWW. This study involves using Al electrodes arranged in a monopolar manner and connected to a power supply with a maximum current of 2.0 A. CWW samples were collected from car wash centres around Parit Raja, Batu Pahat. Several operating parameters, such as current density, initial pH, and electrocoagulation time, have been selected to determine the optimum conditions for EC treatment methods specifically designed to treat CWW. The results of the study exhibit that the optimum conditions have been determined at a current density of 29 A/m2, CWW initial operating pH of 8 and an electrocoagulation time of 70 minutes to achieve the highest level of uptake for turbidity (91.2% removal), SS (82.7% removal) and COD (64.8% removal). These findings underline the ability of this treatment method to remove targeted contaminants from CWW. This study contributes to developing a treatment technique that is more practical for treating CWW. In addition, this study also has important implications in mitigating water pollution, preventing ecosystem damage, and reducing health-related risks due to improper discharge of CWW.
A Simulation of Flood Hazard Map to Mitigate Heavy ARI Flood in Sungai jijan, Negeri Sembilan, Malaysia
Authors: Abd-Aziz A Q A , Ridzuan M B , Daud Z , Zakariah Z
Published: June 2024

Forests and soils absorb rainwater naturally. New colonies were established without proper environment evaluations in cities and isolated areas. Hydrology analysis uses meteorological data and catchment physical characteristics to estimate discharge in river and drain systems. A few 2D hydrodynamic software, such as HECRAS and ICM, can produce flood hazard maps for urban and river catchments. By combining 1D and 2D modelling, catchments can be fully modeled, including below-ground and above-ground elements. The river and flood plain model have three main components: hydrology, 1D, and 2D models. River and 2D model for flood plain with sub-catchment info imported to create hydrological and hydraulic components. The IFSAR 3D ground model is supplied by the Department of Irrigation and Drainage and offers crucial information for 2D hydraulic analysis. Emphasize accurate ground model data for future service providers. Therefore, the flood area in Sg. Jijan is 2922.316m in current land (CL) for 100 ARI and after future land (FL) 391.185m in 100 ARI. Lastly, the number of houses affected by the flood is 148 houses in 100 ARI future land.
Ability of Ceramic Composite Beads as a Pre-treatment for Laundry Wastewater and Preparation of the Process
Authors: Bakar S A , Nizam N S M , Musa S , Mohamed R M S R , Khamidun M H , Al-Gheethi A
Published: June 2024

The escalating demand for laundry services, particularly in university districts, has raised concerns about its impact on biodiversity. The situation becomes even more critical when wastewater is discharged into drainage systems without adequate treatment. This study aimed to enhance laundry wastewater treatment by employing ceramic composite beads using ceramic sanitary ware waste and chitosan. The investigation began by characterizing laundry wastewater to identify its specific attributes. Subsequently, the study quantified the removal of zinc as a metal during the laundry wastewater treatment process. Laundry wastewater characteristics were assessed using various parameters, including pH, chemical oxygen demand (COD), total suspended solids (TSS), and turbidity. The result revealed that the treatment of laundry wastewater with ceramic composite beads adsorbent successfully achieved over 50 % reduction in zinc concentration. These findings showed that the ceramic composite bead exhibited an efficiency for metal removal from the laundry wastewater for safe disposal.
Embodied carbon consideration for maintenance & repair appraisal in heritage building: a review
Authors: Mahmad M S , Suratkon A , Ismail S
Published: June 2024

Reducing carbon emissions is critical to mitigating climate change, and the building sector is one of the largest contributors to carbon emissions, accounting for around 39%. Recent evidence has shown that accounting for embodied carbon in life cycle assessment (LCA) could help reduce carbon emissions during the maintenance and repair phase. This paper narratively examines the literature review of embodied carbon considerations in the life cycle assessment (LCA) of historic buildings during the maintenance and repair phase. The search for all previously published articles was conducted in various databases using specific keywords identified as relevant to this study. The results of the database search were summarized and synthesized after review to ensure that the research questions could be met. The results show that considering embodied carbon in the LCA is essential when selecting the maintenance or repair approach taking environmental aspects into account. In addition, this study also highlights the importance of maintenance durability on the amount of embodied carbon consumed during the maintenance and repair phase. Furthermore, the lack of policy and legislation on carbon consideration in heritage conservation is seen as a major challenge in this area. This finding also suggests that there is a lack of interest in this area among policymakers, so this area needs to be studied in depth to address this issue. The study recommends developing a procedure that incorporates embodied carbon consideration into the existing decision-making process for preserving historic buildings. The procedure is intended to help select the best maintenance and repair approach that not only preserves the value of the structure but also results in the lowest possible carbon consumption during the maintenance and repair phase. The developed procedure should be tested and evaluated in a heritage conservation project to convince policy makers that life cycle carbon calculations should be included in the regulations.
Reviewing the benefits to promote sustainable retirement villages in Malaysia
Authors: Julaihi F A , Amat Rais S L , Ejau R L , Husin N I
Published: June 2024

Retirement Village is a care retirement community that supports independent living among older adults and is tailored to meet the diverse needs of these older residents. Malaysia is fast approaching becoming an aging country; it is estimated that by 2050, the country’s population aged above 65 will be more than 15 percent, and thus, the demands for older people’ homes are predicted to be on a tremendous rise. Notwithstanding those various studies started gaining traction among researchers, it is still considered a relatively new idea in Malaysia. Along these lines, this paper aims to look at the benefits of social, economic, and environmental aspects of promoting retirement villages in Malaysia through an extensive and intensive literature review. The findings of the study indicate that there are various benefits of a retirement village in terms of the economic value; it is affordable and has lower cost, whereas the social aspect it encourages social interaction which helps to improve health conditions and from the environmental aspect it enhances the quality of life of these older adults. Hence, this study revealed that a retirement village made affordable with a high-quality environment that enhances the residents’ well-being is an ideal living concept that can influence the attitude and willingness of older adults to move into a retirement village.
Analysis of Damage to Residential Buildings Due to Ground Movement Resulting from Man-Made Excavation in Soil Swelling Potential Zone
Authors: Agung P A M , Mustaffa A A , Djamal A , Hasan M F R , Zainorabidin A , Susilo A , Suryo E A
Published: June 2024

Sometimes, an activity of open excavation for the basement area of a new infrastructure does not pay attention to the environmental, geological, and geotechnical aspects. The excavation performed on the soil with swelling potential will involve problems during construction implementation. The wrong standard operational procedures will result in environmental damage, including buildings around the construction site. One case occurs in Cikarang, West Java, and is a subject of this study. This research aims to use geotechnical and geosurvey methods to determine the causes of damage in residential areas due to the construction of basement areas in new hotels. The results study found the reduction of a factor of safety (FS) before the excavation process was between 1.20 to 1.40, and after the excavation existed at 0.70 to 0.80. From the field observation, data studied from field and laboratory geotechnical data, and some analysis using the geotechnical software, the damage was caused by the ground movement during the excavation process in the soil with swelling potential. Intensive analysis shows that the deformation due to ground movement reached 3.0 - 9.0 mm using the geotechnical method, close to the actual measurement using the geosurveying method. The final condition is unstable, and some effort is required to recondition.
Green roof thermal performance of small-scale prototype using IES-VE simulation in tropical climatic condition
Authors: Md Yacob M N , Kasmin H , Rahmat S N , Tukimat N N A , Ahmad Nazri M A
Published: June 2024

This study investigates the thermal performance of green roof systems in a tropical climate, focusing on the small-scale building prototypes. Batu Pahat, Malaysia is experiencing the increasing temperatures due to climate change. Green roofs are considered as a potential solution, but their effectiveness depends on various factors such as building orientation, solar shading, and thermal resistance (R-value). Therefore, modeling and simulation are crucial for understanding green roof thermal behaviour. This study employs the Integrated Environmental Simulation Virtual Environment (IES-VE) software for analysis. Three identical small-scale buildings were constructed, one with Portulaca Grandiflora (PGR) plants, another with Alternanthera Paronychioides (ATN) plants, and a control roof with no vegetation. The R-values from the on-site green roofs were measured at 0.8899 m²K/W for PGR and 1.1477 m²K/W for ATN, while the control roof had an R-value of 0.1 m²K/W. Green roofs with higher R-values demonstrated a substantial reduction in indoor temperatures, making them a valuable solution for improving thermal comfort in tropical climates. This study underscores the importance of green roofs in mitigating rising temperatures in tropical climates. Simulation using IES-VE approved that green roofs can potentially reduce indoor temperatures, demonstrating their suitability for tropical regions. These findings have significant implications for sustainable building design and urban planning in hot and humid climates.
Analytical study on effect of groundwater table and rainfall infiltration on the stability and performance of Muar Trial Embankment by using PLAXIS 2D
Authors: Sim M L , Ling F N L , Zaihasra A T
Published: June 2024

Stability and performance of embankment is crucial throughout its service life especially when subjected to various environment factors namely rainfall and fluctuation of groundwater table. The environmental factors are normally site dependent and vary from time to time. Thus, it is critical to assess the stability and performance of embankment when subjected to environmental factors. The geometry and soil profile of well documented Muar Trial embankment was utilized as base model with the aim to determine the effect of water table and rainfall infiltration on its stability. The impact of these factors on embankment stability is investigated numerically via Plaxis 2D. The findings highlight the importance of considering fully coupled flow-deformation analysis in PLAXIS 2D when simulating rainfall infiltration on the embankment slope. Stability of simulated slopes was determined via strength reduction technique which is known as one of the FEM methods to determine slope stability. The findings showed that the short-term safety factor of slope is slightly increased with 0.4 by taking into consideration possibility of water table raise due to poor drainage. However, simulated 1-day rainfall event didn’t significantly affect the stability of embankment slope. Future work should explore consolidation process after drawdown of water table and incorporating long-term rainfall data to validate the practical assessment of embankment stability in engineering scenarios.
Measurement uncertainty evaluation in soil liquid limit testing
Authors: Lua K L , Lim A J M S , Sim S Y
Published: June 2024

Measurement uncertainty provides an indication of the quality of test result and very often also adopted in laboratory proficiency testing activities. Soil mechanical properties testing for example plastic and liquid limits conventionally do not provide uncertainty figure; however due to laboratory accreditation requirement, laboratory is required to provide it in the test report for some specific purposes for example Proficiency testing and quality validation. Conventional approach to derive measurement uncertainty is too difficult or mathematically unable to justify for the figure derived because liquid limit is not obtained experimentally instead it is estimated through linear regression method. Thus, it becomes a problem to report accurate and reliable measurement uncertainty figure in the test report. This research focuses into estimating the water content of liquid limit with relative uncertainty approach through estimation from the regression curve. It suggested the technique for estimation of water content and dry weight resulting in uncertainty component different treatment from conventional approach. Error of regression, a Type A component becomes one of the key components dominating the final answer. This study suggests the control of quality and improvement of measurement uncertainty evaluation through curve fitting observing the value of R2. should not be less than 0.95. This uncertainty figure can be used in proficiency testing and inter-laboratory comparison purpose.
The study of cement sand brick containing kenaf fine particles as sand replacement materials
Authors: Ayop S S , Umar Radzi U A R
Published: June 2024

Besides concrete, bricks are the most fundamental building materials used in the construction of buildings, such as a partition walls. For cement-sand bricks, the used of sand as a main ingredient had triggered a big concern to the environment impact, a shortage of sand resources and the rise in the cost of the material. To address this problem, many researchers have been exploring the use of kenaf fiber as an alternative, renewable resource for fine aggregate in construction. This study is focused on the cement sand brick that containing kenaf fine particles. Due to its unique properties and availability, kenaf has gained much attention among researchers. The main objective of this study was to determine the optimum amount of kenaf fine particles as sand replacement in cement sand brick. Seventy-two brick of 215 mm x 102.5 mm x 65 mm has been produced. In this investigation, a brick with a cement sand ratio of 1:3 and a water-cement ratio of 0.4 with and without superplasticizer, and 0.5 has been tested. The replacement of kenaf fine particles was ranging from 10% to 30% by volume. The cement sand brick was tested to investigate mechanical parameters such as density, compressive strength, and water absorption capabilities of the brick. The results shows that 20% kenaf replacement gave an acceptable condition in term of strength and density.
Stabilization of peat using sugarcane bagasse ash (SCBA) and cement as a stabilizer
Authors: Bakhir M A , Abu Talib M K , Madun A , Md Dan M F , Pakir F , Md Yusof Z
Published: June 2024

One of the main land types in Malaysia is peat, which has relatively soft soil with a high organic content, poor shear strength, and high compressibility. Therefore, in its natural state, peat is deemed unsuitable for supporting a construction site. Cement is one of the techniques used to stabilize peat. However, because so much cement is used, this process is not environmentally beneficial. at this work, the stabilization of peat was achieved by using Sugarcane Bagasse Ash (SCBA) at a ratio of 5% to 20% in lieu of Ordinary Portland Cement (OPC). To determine the strength of the soil and the differences in microstructure between treated and untreated soil, laboratory experiments on the physical, chemical, and mechanical properties have been carried out. Through testing unconfined compressive strength (UCS), the optimal mix of replacement SCBA with OPC, consisting of 15 PCBA, demonstrated enhanced strength. The microstructure of a sample of 100 PC with 15 PCBA that is hollow is reduced and becomes denser as a result of the filler material SCBA’s reaction, as shown by a scanning electron microscope (SEM). The test Energy Dispersive X-Ray (EDX) with the lowered of carbon and calcium rise value shows the pozzolanic reaction. It may, indirectly, strengthen peat following stabilization.
The performance of steel fibre reinforced concrete with waste glass as partial replacement of fine aggregate
Authors: Yusuf A M , Ali N
Published: June 2024

This paper discusses the performance of steel fibre reinforced concrete with part of substitution of sand with waste glass in concrete mix. Glass consists mainly of silica, which is a natural raw substance like sand. Glass is completely recyclable, and it can be recycled indefinitely without losing any of its quality or purity. Waste glass powder was utilized as a partial replacement of fine aggregate with 0%, 10%, 20 and 30% by the volume in C30 grade of concrete and addition of 0.5 % steel fibre by volume fractions of hooked end steel fibre and 0.5 water cement ratio. All samples were evaluated following 28 days curing period. The aim of this study is to investigate the workability of concrete, to determine the compressive and tensile strength of concrete and to identify the optimum percentage of steel fibre reinforced and waste glass. From the experimental results, it was found that the study achieved a maximum compressive strength of 32.9 N/mm² at 30% replacement of fine aggregate with waste glass, slightly surpassing normal concrete. Additionally, the highest tensile strength of 3.9 N/mm² was achieved at 20% replacement, surpassing normal concrete. The optimum percentages determined were 20% for fine glass replacement and 0.5% for steel fiber addition. It can be concluded that scenario of waste glass concrete approach could be perceived as a sustainable and environmentally friendly product in the near future.
Fatigue of notched steel hollow sections under sinusoidal cyclic loading
Authors: Jaini Z M , Sugiura K , Sato A , Jamaluddin N , Badrul Azman M F N , Abdul Kudus S
Published: June 2024

This paper presents the numerical modelling of the fatigue of notched steel hollow sections under sinusoidal cyclic loading. Steel hollow sections are commonly used as structural components, particularly for beams, columns, girders, trusses and bracing. The biggest concern is flaws or minor cuts that create notches in the steel hollow sections. The presence of a notch could degrade the strength properties and consequently lead to severe disadvantages in fatigue life. The fatigue assessment was carried out using the finite element program WELSIM. SHS50×50×3.0 was selected for the three-dimensional model. The sinusoidal cyclic loading was applied with a minimum force of 1.665 kN and a maximum force ranging from 5.550 kN to 16.65 kN. Variables such as notch depth and amplitude ratio were simulated to acquire the stress range and the number of cycles. The results showed that the stress range for unnotched specimens is 46.258 MPa to 164.93 MPa; for notched specimens, it is 52.273 MPa to 189.89 MPa. It was found that the presence of a notch leads to an increase in the stress range and a decrease in the number of cycles. The unnotched specimens can withstand the number of cycles from 1.83×106 to infinity. Meanwhile, the number of cycles for notched specimens ranges from 1.20×106 to 8.36×107. At each amplitude ratio, except for A = 0.10, the number of cycles is insignificant.
Crack Width Behaviour of High-Performance Fiber Reinforced Concrete Slabs Affected by Steel Fiber Composition
Authors: Krisnamurti
Published: June 2024

When a bending failure occurs, the crack width formula of a reinforced concrete element usually requires a parameter of relative crack depth (ξ) or a span-to-depth ratio (L/h). Using High-Performance Fiber-Reinforced Concrete (HPFRC) increase material performance so the element thickness can be cut down and the relative crack depth can be raised. The research aims to investigate the HPFRC slab’s crack width, which is affected by a variation of steel fiber composition as a pure bending element based on the linear elastic fracture mechanics. The HPFRC materials use Portland pozzolana cement, sand, gravel, silica fume, water, superplasticizer, and the composition of steel fiber of 0,4%, 0,6%, 0,8%, and 1,0% based on the prediction weight of HPFRC slabs. The research generates the stress intensity factor and the crack width equation as a function of the relative crack depth of the HPFRC slab less than 0,90. The comparison between the crack width analysis on the HPFRC slab and the flexural test result on the HPFRC slab shows well conformity.
On normalizers of maximal tori in classical Lie groups
Authors: Gerasimov A. , Lebedev D. , Oblezin S.
Published: June 2024

In general, the normalizer

N
G

(

H
G

)

N_G(H_G)

of a maximal torus

H
G

H_G

in a semisimple complex Lie group

G
G

does not admit a presentation as a semidirect product of

H
G

H_G

and the corresponding Weyl group

W
G

W_G

. Meanwhile, such splitting exists for classical groups corresponding to the root systems

A
ℓ

A_\ell

,

B
ℓ

B_\ell

,

D
ℓ

D_\ell

. For the remaining classical groups corresponding to the root systems

C
ℓ

C_\ell

, there still exists an embedding of the Tits extension

W
G
T

W^T_G

of

W
G

W_G

into the normalizer

N
G

(

H
G

)

N_G(H_G)

. Here an explicit unified construction is proposed for the lifts of the Weyl groups into normalizers of maximal tori for general linear and orthogonal Lie groups via embedding into the general linear groups. For the symplectic group

S
p

2
ℓ

\mathrm {Sp}_{2\ell }

, an explanation of the impossibility of embedding

W

S
p

2
ℓ

W_{\mathrm {Sp}_{2\ell }}

into the normalizer

N

S
p

2
ℓ

(

H

S
p

2
ℓ

)

N_{\mathrm {Sp}_{2\ell }}(H_{\mathrm {Sp}_{2\ell }})

is suggested. Also, explicit formulas are computed for the adjoint action of the lifts of the Weyl groups on

g

=

L
i
e

(
G
)

\mathfrak {g}=\mathrm {Lie}(G)

. Finally, examples of Weyl groups lifts are given for the groups closely associated with classical Lie groups.
Bernoulli numbers in embedding constants for Sobolev spaces with diverse boundary conditions
Authors: Sheipak I.
Published: June 2024

The Sobolev spaces

W
2
n

[
0
;
1
]

W^n_2[0;1]

are treated with five different boundary conditions (periodic, antiperiodic, of even and odd orders, and of even-odd order). Sharp estimates for the derivatives of order

k
=
0
,
1
,
…
,
n
−
1

k=0,1,\dots , n-1

are obtained, sharp constants for the embedding of

W
2
n

[
0
;
1
]

W^n_2[0;1]

into

W
∞
k

[
0
;
1
]

W^k_\infty [0;1]

are found, it is shown that they are rationally expressed in terms of Bernoulli numbers and, therefore, are rational. The exact embedding constants can also be expressed in terms of the Riemann

ζ
\zeta

-function. The reproducing kernels of these spaces are calculated.