bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation on the new design method of heat source for reducing the energy consumption in the shaft antifreeze system
Authors: Bai Yanbin , Yang Lizhong , Zheng Song , Tang Weiwei
Published: March 2021

In order to suppress the heat consumption for shaft antifreeze in coal mines, this study first analyzed the meteorological data required for shaft antifreeze in typical five cities (Harbin, Yulin, Hefei, Guiyang, and Nanning) located in different climate zones in China. The analysis results explain why some shaft heating measures must be taken in severely cold regions. So, in this study, Harbin is taken as the case city for research to show that the traditional heat load design methods have the problem of mismatching between the actual heat load and the designed heat load. Next, the annual temperature change analysis in Harbin reveals that the occurrence frequency of the extremely low temperature in a year is small and its continuation time is short. According to this finding, a new heat load design method is proposed based on the dual heat source usage. In this new method, the main heat source will be designed for flat-peak heat load compensation and the standby heat source will be designed for peak heat load compensation. The main heat source should be selected based on the outdoor calculated temperature for the shaft antifreeze system. The standby heat source should be selected based on the mean value between the average of the year-over-year lowest temperature and the outdoor design temperature for the adit system and on the average of the year-over-year lowest temperature for the vertical/inclined shaft system. The standby heat source accounts for 13% of the total heat load and the main heat source accounts for 87% of the total heat load in the adit system. On the other hand, the standby heat source accounts for 23% of the total heat load and the main heat source accounts for 77% of the total heat load in the vertical/inclined shaft system.
Influence of the calcination temperatures on thermal properties of natural iron ore for heat energy storage
Authors: Ma Huibo , Du Xiaoze , Ma Shiping , Liu Yu , Zhao Pengxiang , Xing Zuoxia , Li Baorang
Published: March 2021

If the iron ore is used as solar heat storage material, it can greatly reduce the cost of thermal storage in concentrating solar power plants due to its lower cost. Therefore, in this paper, we made a foremost investigation on the temperature dependence of the thermal properties of the natural ore. With the help of the X-ray diffraction, scanning electron microscopy and differential scanning calorimeter, thermal properties of the samples were measured and analyzed.
Research on the method of dynamic PDC cutters distribution
Authors: Peng Qi , Zhou Yingcao , Yang Xiongwen , Liu Yu , Cheng Chris
Published: March 2021

PDC bit design, especially the design of the crown and cutters of PDC bit, is a relatively complex analysis process, which involves many factors such as the back-dip angle, cutting depth, cutting force, cutting power and other factors of PDC cutters. At present, the traditional design methods of PDC cutters distribution are mostly based on analysis of rock breaking efficiency of single cutter, which can only reflect the working state of the single cutter under the set parameters, and cannot fully reflect the differences of different positional cutters during the cutting process. In order to solve this problem, this article proposes a dynamic method through target formation lithology characteristics. The working parameters of all the PDC cutters are analyzed in detail basing on equal wear theory and bottom hole covering theory. The working parameters include static parameters (cutting position, back dip angle, cutting depth, effective cutting area.) and dynamic parameters (cutting force, cutting power, cutting torque and cutting energy etc.). The energy required by all the PDC cutters to break rock of per volume during drilling process is taken as the target constraint condition for iterative analysis. This design method can intuitively and effectively analyse the working parameters of cutters which located bit core, nose, shoulder and gauge area, and it provides a good reference for dynamic balance design of PDC bit.
A simulation study on the effect of the dispersion on the process of enhanced oil recovery
Authors: Wang Deqiang , Zhang Xiansong , Zhang Jian , Cheng Linsong
Published: March 2021

Gas injection is a potential proven enhanced oil recovery technique due to the difficulty of injecting water in the low permeability reservoir. In the process of gas flooding, there is mass transfer between fracture-matrix, which is called diffusion due to the fluid velocity difference in matrix and fractures. In the complex fracture network formed by hydraulic fracturing in the low permeability formation, this mass transfer is widely existed. However, it is often neglected in the past studies about optimization design of gas flooding. In this paper, embedded discrete fracture model (EDFM) using vectorization programming is built which is easy to obtain pressure gradient and velocity to characterize dispersion caused by velocity difference between matrix and fracture. And the EDFM is used to simulate the gas flooding for a typical well, which is in good agreement with Eclipse verified the accuracy of the model. Through a series of comparisons, the influences of different fracture network mode, matrix permeability, dispersion and gas injection rate on gas flooding are analyzed and the well performance is comprehensively evaluated considering the fracture network and the dispersion in the gas flooding.
A CFD computational model for high-pressure liquid CO2 decompression
Authors: Xiao Chenghuan , Lu Zhaijun , Yao Shujian , Yan Liguo , Wang Jiaqiang
Published: March 2021

A CFD decompression model with considering external flow field is established based on the non-equilibrium phase transition. The results of pressure and decompression wave speed calculated by CFD are compared with the results of “shock tube” test, showing good agreement. On this basis, the effects of external flow field on the transient behaviour of liquid CO2 decompression in the pipe is further investigated. It is found that the external flow field basically has no effect on the variation of pressure and decompression wave speed in the pipe. Moreover, a Mach disk is formed at about 7.35R (R is the radius of rupture opening, 19.05 mm) away from the rupture opening in the process of jet expansion. Although the external flow field has a significant influence on the static pressure at the rupture opening, the mass flow in the case without considering external flow field is larger than that with considering external flow field, and the overall difference between the two cases is within 6%.
Ship Hydrodynamics of Several Typical Scenes During Inland Waterway Transport
Authors: Li Zhuoyue , Du Peng , Ouahsine Abdellatif , Hu Haibao
Published: March 2021

Environmental effects on ship hydrodynamics during inland waterway transport are investigated using both CFD (Computational Fluid Dynamics) and towing tank experiments. Three important scenes, the confinement effect of the waterway, head-on encounter and ship-bridge pier interactions are studied. The testing conditions cover a wide range, including various channel dimensions, water depths, ship draughts and speeds. The ship resistance, wave pattern, Kelvin angle and wave elevations are investigated as functions of these parameters.
Effect of Drip Irrigation with Magnetised Water and Fertiliser on Cotton Nutrient Absorption
Authors: Nie Jing , Wang Nianyi , Wang Kang , Li Yang , Chao Xuewei , Li Jingbin
Published: March 2021

In order to improve the nutrient absorption effect of cotton in the process of simultaneous application of water and fertiliser, this paper studied the effect of injecting magnetised water and fertiliser on cotton nutrient absorption under the production conditions of drip irrigation. In the process of integrated water and fertiliser management of cotton, the study adopted the method of magnetisation treatment—After the water-fertiliser fusion liquid is magnetised by a magnetisation device, it is dripped on the cotton field through the drip irrigation pipe network. In this work, the water and fertiliser magnetisation device was designed, and it was combined with the drip irrigation pipe network as a test device. The nutrient absorption test of the water-fertiliser fusion liquid applied to cotton under different magnetic fields was conducted. The accumulation, absorption and distribution of cotton biomass and N, P and K elements were studied respectively. As a result of the research, we found that the magnetised water and fertiliser treatment can promote cotton nutrient absorption to varying degrees. A method of drip irrigation under a magnetised water and fertiliser film to improve the nutrient absorption effect of cotton was proposed.
Overview of Nitrogen Removal in Constructed Wetland and Its Influencing Factors
Authors: Tang Gang , Shi Yucui , You Shaohong
Published: March 2021

Nitrogen, as a common substance in water pollution, can easily cause eutrophication of water when it is excessive. Constructed wetland, as a water treatment method that combines the common actions of plants, microorganisms, and substrates, has positive significance for the removal of nitrogen. This article reviews the nitrogen removal mechanism of each component in constructed wetlands, and the effects of temperature, carbon-nitrogen ratio, dissolved oxygen, pH, and HRT on denitrification, and proposes existing problems and research directions in constructed wetlands.
The Influence of Cysteine on the Performances of Gelatin Film
Authors: Yu Hong , Wang Bowen , Yu Peng
Published: March 2021

In order to explore the cysteine as a potential plasticizer for gelatin films, the influences of the amount of cysteine, pH and reaction temperature on the functional performances including water absorption, mechanical performances, and chromaticity of gelatin films have been investigated. The results indicated that the amount of cysteine, pH and reaction temperature did not affect the water absorption and chromaticity of the gelatin film. However, the mechanical performances of the gelatin film were influenced greatly by the amount of cysteine and water bath temperature. With the concentration of cysteine ranging from 0 to 0.02%, the tensile strength (TS) of the gelatin film had no significant change but the elongation at break (EB) increased gradually. When the concentration of cysteine ranged from 0.01% to 0.02%, the largest value of the EB of gelatin film was obtained. When the concentration of cysteine was greater than or equal to 0.04%, the TS and EB of the gelatin film decreased significantly. When the reaction temperature was 60 ∼ 90°C, the largest values of the EB and TS of the gelatin film were obtained. The addition of cysteine as a plasticizer can improve the EB of gelatin film, but has no influence on other performances. Therefore, there is a promising application value for cysteine in food preservation packaging film, due to its advantages of biodegradability and wide source.
Investigation of the Salinity Distribution of the Soil along West Main Canal in Ningxia, China
Authors: Wu Juntao , Jing Hefang , Wang Weihong , Guo Xiaoxiao , Guo Xinxia
Published: March 2021

As one of the main irrigation canals in Ningxia, West Main Canal plays a very important role in the irrigation of the land nearby the canal, such as farms, meadows, and tree farms. Because of the long-term use of the Yellow River water for irrigation, the soil salinization in this area become more serious. In this paper, the problem of soil salinization along the West Main Canal in Ningxia is taken as the research object. 82 sample points in the studied area are chosen and a total number of 164 soil samples are measured for the eight main salt ions and pH value. Correlation analysis and principal component analysis are employed to study the distribution of the soil salinity ions and pH value. In addition, two dimensional interpolation is applied to obtain the spatial distribution of the total saltiness. It can be found that Cl−, SO42−, Ca2+, Na+ and HCO3
− are the main salt ions and the main soluble salts are NaCl, KCl, CaSO4, Na2SO4 and CaCl2 in the soil of the studied area. The spatial distribution of the total soil salt is mainly in the patterns of north high and south low, far high and near low, up high and down low.
Experimental Study on Flow Characteristics in a Compound Open Channel with Flexible Vegetation
Authors: Guo Xiaoxiao , Jing Hefang , Wang Weihong , Wu Juntao , Zhang Qiaoling
Published: March 2021

In order to study the effect of flexible vegetation for the flow in open channels with flood plains, a series of experiments were carried out in a laboratory flume with a two-stage floodplain. Four cases, i.e., dense parallel arrangement, normal parallel arrangement, sparse parallel arrangement and no vegetation condition, were designed with fixed water depth and discharge. By using three dimensional (3D) laser Doppler velocimeter (LDV) and other instruments, under the condition of the four cases,3D flow velocities, water level and turbulence intensity were measured, The experimental results show that, compared with the non-vegetation situation, the arrangement of grasses on the floodplain will increase the water surface gradient, hydraulic gradient and turbulence intensity to a certain extent.
Risk Assessment of Water Pollution in Urban Rivers of Northwest China
Authors: Liu Yinge , Zhou Huanhuan , Zheng Runhe , Bao Jiangchuan , Yang Yuxin
Published: March 2021

As the main carrier of regional residential sewage, industrial wastewater and surface runoff emissions, urban rivers are most vulnerable to pollution and destruction. Taking the Dongsha River in the city of Baoji in Northwest China as an example, four river pollutants were monitored, and the improved Nemero index and factor information model were established to for risk assessment of river water pollution. While compared with other methods, the method is verified, and it is believed that this method is a good tool to evaluate the water pollution of urban rivers. Moreover, the source load mechanism of urban river pollution is discussed. Evaluation results show that for TP, risk of upstream is highest, and for COD and NH3N, risks of the middle are highest, while for PH, risk of downstream is highest. Overall, COD and ammonia nitrogen are a major pollutant in urban rivers, which pollutants originate from industry and agricultural wastewater discharge. The domestic sewage, solid waste and agricultural wastewater overflows also play an important role in the change of river water quality. These studies provide the basis for urban environmental planning and pollution control.
Analysis of Horizontal Displacement Monitoring Data of Shimenzi Arch Dam after “12.8” Earthquake
Authors: Li Yinan , Zhang Tingting , DuanMu Lingzi
Published: March 2021

Concrete arch dam is a high-order statically indeterminate structure with strong seismic capability and high safety. The Shimenzi Arch Dam (110m high) located in Manas County, Xinjiang Province was affected by the "2016.12.8 Earthquake" (magnitude 6.2) in Hutubi County and the dam body was deformed to some extent after the earthquake. In order to study the effect of “12.8 earthquake” on the stability of Shimenzi arch dam, the author analyzes and studies the radial displacement, tangential displacement, and deflection distribution of the Shimenzi arch dam basing on the horizontal displacement monitoring data of Shimenzi Arch Dam before and after the earthquake. By drawing the process lines related to displacement, water level, temperature related process line, the deflection distribution, statistical characteristic value of dam deformation before and after the earthquake, and analyzing the deformation trend after earthquake, the author thoroughly discussed the impact of the displacement and deformation caused by the earthquake on the operation safety of the dam, meanwhile evaluated the seismic performance of the arch dam.
Pushover Analysis of 10-Floors Reinforced Concrete Building (Case study: Mahkota Majolelo Sati Bautique Hotel)
Authors: Masrilayanti  , Kurniawan R , Budi A L , Sourkan S H
Published: March 2021

Analysis of nonlinear pushover (push load) is one component of performance based design that can be used as a means of determining the capacity of a structure. The analysis is carried out by giving a static lateral load pattern to the structure whose value is increased gradually until a displacement target is reached or until the structure collapses. The purpose of this study is to determine the performance level of the building structure of the MahkotaMajolelo Sati Bautique Hotel according to the ATC-40 document. The capacity curve can estimate the basic shear force and maximum deformation that occurs in the structure. The results of the pushover analysis can show the pattern of collapse and the scheme of the occurrence of plastic hinges in the structure when given loading. By looking at the scheme of the occurrence of plastic hinges, then it can be seen the critical parts of the structure of the Majolelo Sati Bautique Hotel Mahkota Building. Pushover analysis is carried out by referring to the new regulations in effect in Indonesia, namely SNI 1726-2019, SNI 1727-2013 and SNI 2847-2019. The performance point is obtained by using the FEMA 440 Equivalent Linearization method, which is a simplification of the capacity spectrum method. The determination of the performance level of the structure follows the ATC-40 document.
Behaviour of Cold-formed Steel Back-to-Back Channel Built-Up Sections under Bending
Authors: Fitrah R A , Melinda A P
Published: March 2021

Cold-formed steel (CFS) structures have been widely constructed as main elements in light structures. In terms of increasing capacity, the built-up sections of cold-formed steel are used regarding larger span structure. In this study, nine cold-formed steel with back-to-back built-up section specimens with various thicknesses were experimentally investigated under three points bending scheme to obtain their capacity and failure type. Each specimen was assembled by using self-drilling screws in web of two built-up channels. Experimental results show that three various web thicknesses (1.3 mm, 1.5 mm, and 2.00 mm) in cold-formed steel of built-up section give the different moment capacity up to 22%. Then, failure types in all specimens are similar where local buckling is generated in compression flange around loading area and lateral-torsional buckling occurred along span. It is found that web thicknesses in back-to-back section have contribution to increase the stiffness and torsional rigidity. However, there is phenomenon when the load capacity decreased, the back-to-back sections act non-composite. Then, the failure apparently observed on that section is one-side twisting and web crippling in mid-span.
Performance Analysis of Diversity Selection Combining on Radio Frequency for Image Transmission
Authors: Baharuddin  , Luthfi A , Andre H , Muharam M , Angraini R
Published: March 2021

This paper describes a simulation of the image transmission system with diversity selection combining (DSC) method on radio frequency. DSC is used to obtain multiple data streams corresponding to the transmitted image at the receiver in order to combat errors during image transmission on wireless channels. These individual image data streams are combined to form a composite image with higher perceptual quality. When DSC is used, it is expected that it can affect the number of errors, so that the signal transmitted to the wireless channels becomes more robust against interference caused by transmission channels. By using DSC technique, it can increase the quality of image transmission at the receiver. The result of the experiment which was carried out to test bit error rate (BER) and peak signal to noise ratio (PSNR) on Lena image with rate 0.8 bpp by using DSC on radio frequency in Rayleigh fading channel showed that there was a decrease in BER at the average of 0.0152 or 3.39%, while for PSNR there was an increase at the average of 1.6737 dB or 6.73%when comparing to the system without DSC.
Performance Analysis of Trellis Coded Modulation and Diversity Combining on Wireless Channel
Authors: Baharuddin  , Andre H , Muharam M , Luthfi A , Angraini R
Published: March 2021

The use of trellis coded modulation (TCM) and diversity maximal ratio combining (MRC) are applied in this research in order to overcome the impairment of information signals caused by fading and noise. TCM is chosen due to its ability to correct error without increasing the transmit power and channel bandwidth. MRC is used to obtain multiple data streams corresponding to the transmitted image at the receiver. The testing of the system is carried out by calculating peak signal to noise ratio (PSNR) and bit error rate (BER). The result of this simulation shows that the use of TCM and MRC in the image transmission system improves significantly compare to the system which only use TCM without MRC.
Application of Life Cycle Assessment (LCA) On Green Tea Product (Case Study in the X Company)
Authors: Mila G , Primasari B , Aziz R
Published: March 2021

This study analyzes the environmental impact of 1 ton green tea 50 gr canned in x company using the Life Cycle Assessment (LCA) method. A cradle to gate approach was used to scope the study, from plantations to packaging. SimaPro version 9 software is used as a tool for assessing LCA. The evaluation step refers to ISO 14044 of 2006, which determines the objectives and scope, inventory analysis, impact, and interpretation. The method used to assess the environmental impacts is the CML-IA Baseline. The classification results of the dominant and significant impact characterization on the environment are global warming with 475.557,7 kg CO2 eq. Drying process II, drying process I, PLN electricity, and transportation contribute to the environmental impact. The recommendation for technical improvement based on the sensitivity analysis results is using PLN electricity with renewable energy, namely micro hydro (PLTMH). The combination of wood biomass with other biomass is rice husks, then changing the truck fuel from diesel to fuel that is morm e environmentally friendly Pertamina Dex.
Spatial Variation of Electrical Conductivity, Total Suspended Solids, and Total Dissolved Solids in the Batang Arau River, West Sumatera, Indonesia
Authors: Helard D , Indah S , Wilandari M
Published: March 2021

This study aims are toanalyze the spatial variation of electrical conductivity (EC) values, total suspended solids (TSS), and total dissolved solids (TDS) concentrations along the Batang Arau River. Water samples were collected from eight stations along the river at biweekly intervalsbetween March and May 2014. The results indicate an increasing trend in the value of three parameters from upstream to downstream, reflecting the effect of natural and anthropogenic activities along the river. The EC values were in the range of 173-5,097 μS/cm and had exceeded the water quality standard established by World Health Organisation (WHO) at the downstream. The TSS and TDS concentrations were in the range of 76-2,078 mg/L and 124-3,560 mg/L, respectively. The TSS concentrations at all stations had exceeded the river quality standard of class II established by Governor Regulation of West Sumatera, while the TDS concentrations had exceeded only at the downstream area. Significant spatial variation of the EC and TDS concentrations was observed between the upstream-midstream and the downstream but was not obtained along the river for the TSS concentrations. It indicates that the anthropogenic activities along the river affected the variability of EC and TDS, but not for TSS. Based on these results, reducing the number of sampling points into three stations could be performed for the EC and TDS, while TSS monitoring at only one station could be applied.
Study on solid waste generation in Lake Toba area
Authors: Suryati I , Khair H , Siregar R L , Sibagariang H , Utami R
Published: March 2021

Girsang Sipangan Bolon and Merek do not have basic data for solid waste management design. This research aimed to analyze the generation, composition of domestic and non-domestic waste. Sampling methods are determined based on SNI 19-3962-1994. The average amount of waste generation in units of volume for the area divider factor and the number of inhabitants for Girsang Sipangan Bolon and Merek are 92,771 and 87,227 m3/day, respectively. This study found the composition of domestic waste in Girsang Sipangan Bolon consists of 65% organic waste; 7% paper; 17% plastic; textiles 6%; rubber 0%; wood 0%; glass 2%; 0% metal and 3% other waste. The composition of non-domestic waste consists of 61% organic waste; 12% paper; 15% plastic; textile 1%; rubber / leather 0%; wood 1%; glass 0%; metal 1% and other waste 9%. In Merek, the composition of domestic waste consists of 69% organic waste; paper 14%; 8% plastic; textile 1%; rubber / leather 0%; wood 0%; glass 2%; 0% metal and 6% other waste. The composition of non-domestic waste consists of 55% organic waste; paper 14%; plastics 21%; textile 0%; rubber / leather 0%; wood 1%; glass 3%; 0% metal and 6% other waste.
Quality improvement of pillow product using Quality Function Deployment (QFD) methods at PT. XYZ
Authors: Ginting R , Ishak A , Primsa I T , Malik A F
Published: March 2021

PT XYZ is a company engaged in the manufacturing of bedding goods. One of the products from this company that will be the object of research is the pillow. The number of disability pillow products that occurred during 2018 amounted to 21.69%, which could cause a decrease in company productivity and the shift of consumers of these companies to competing companies. The method used to improve the quality of pillow products is Quality Function Deployment. In QFD Phase I, consumer desires are translated into technical characteristics. The results of QFD Phase I, show that the highest priority technical characteristics are machine capacity with a difficulty level of 4, importance of 20% and estimated cost of 19%. Determination of product critical parts using QFD Phase II. The results of QFD Phase II show the highest priority of critical parts based on the level of difficulty, degree of importance and estimated cost is durability of 20%, measurement accuracy of 15% and fabric dimensions of 15%.
Sustainable plastic waste management strategy: Optimization of plastic manufacturing plant waste (gas and product transition)
Authors: Khair F , Matsana J
Published: March 2021

Production waste management has become the key to a sustainable manufacturing operation strategy. This study aims to analyse the waste gas and production waste from the polymerization process, especially the residual exhaust gas from the degassing unit and the final product from the product transition process that does not meet the requirements. Research using qualitative and quantitative methods. The analysis is done by calculating the amount of gas removed from the sweeping or degassing process and calculating the material balance of the production process to analyse the process loss. The results show that the largest contributor to the waste gas is from the degassing process and the pellets from the transition products. In addition, an optimization process is needed to recover exhaust gas with a recovery system and perform a trimming process or a mixing process to reduce the transition product to become prime product.
Assessment of Rotational Accelerometer Mountings for Rotational Frequency Response Function Measurement
Authors: M W I I W I , Rani M N A , Rosli M I M , Yunus M A , Febrina Rina , Shah Mohamad Azam Shah Aziz
Published: March 2021

Kistler Kshear 8840 piezoelectric rotational accelerometer is designed with an M5 bolt type of mounting and a 5mm diameter of through or pre-tapped hole is required in a structure under test. However, the mounting is not applicable for some cases, and other types of mounting need to be used. This work investigates the applicability and accuracy of five different configurations of mounting for Kistler Ksher 8840 piezoelectric rotational accelerometer for the measurement of the rotational FRFs of a steel plate. The mounting configurations consist of 3D printed PLA and ABS mounting, bee’s wax, steel, and bolt mounting. The rotational FRF of the steel plate was measured by using impact testing method. The applicability and accuracy of the mountings were evaluated by comparing the measured FRFs with the finite element (FE) FRFs counterparts. The comparisons of the results revealed that using the bee’s wax mounting had produced the most accurate and least noisy FRF. It was also found that using the 3D printed PLA mounting had contributed to the highest contamination of noise and several spurious peaks in the measured FRFs. These findings provide useful information for selecting the appropriate types and designs of mounting for the Kistler 8840 rotational accelerometer.
Experimental Studies of Application Passive Momentum Exchange Impact Damper (PMEID) on UAV’S Landing Gear
Authors: Darmawan  , Son Lovely , Bur Mulyadi , Nurmansyah
Published: March 2021

Unmanned aircraft or UAV (Unmanned Aerial Vehicle) is a future technology that continues to be developing. This research examines the structural vibration acceleration response of the aircraft’s nose landing gear. The landing gear is the part of the aircraft that receives the most significant shock load during landing. This is due to the magnitude of the maximum acceleration of the landing gear vibration when experiencing shock loads. This phenomenon causes the landing gear damaged due to excessive vibration. Therefore, uncontrolled shock loads can damage the landing gear structure and even pierce its frame structure. A momentum transfer method was applied to the landing gear design to reduce the maximum acceleration amplitude of vibration due to experiencing shock loads during landing. The research experiment was carried out using the principle of passive momentum transfer; the test was carried out by dropping the landing gear at a certain height. When the landing gear experiences a shock load, kinetic energy and momentum will be transferred to the PMEID system so that the landing gear remains in a stable condition. The experiment gives an output in the form of the vibration acceleration amplitude of the landing gear measured by the accelerometer sensor on the landing gear’s main mass. The vibration response will then be sent to the voltage amplifier and forwarded to the digital signal processing and displayed on a computer monitor. The test results prove the application of the momentum transfer method in the landing gear design can reduce the maximum amplitude of vibration acceleration when landing.
Evaluation of controlled low strength materials containing red brick construction waste based on mechanical experiments and BP neural network
Authors: Wang J G , Zhang J X
Published: March 2021

In this study, two kinds of controlled low-strength materials (common and rapid-hardening) were designed and prepared by using red brick construction waste fines. Fourteen mixture specimens were prepared with the control parameters of binder to construction waste fine aggregate ratio (α), accelerator to binder ratio (β), and water to solid ratio (γ). The flowability of fresh mixtures, compressive strength of hardened materials were studied. Test results show that it is applicable to use the red brick construction waste fine aggregate to prepare controlled low-strength materials. Increasing α and γ can increase the flowability, however with different the influence mechanisms, where γ has a more significant effect. The 2 hour-strength of rapid-hardening CLSM (controlled low strength material) based on sprayed concrete accelerator can be up to 0.41∼0.79MPa, which meet the needs of emergency backfill engineering. Using on the BP neural network, the long-term strength prediction model of CLSM is established, which can help the civil engineers in the material mix-design.
Using Crumb of Tires in Hot Asphalt Mixture as a Part of Aggregate
Authors: Mohammed Al-Hasani , Yang Qun , Al-Bukhaiti Khalil
Published: March 2021

Scrap tires are a major part of the global solid waste management problem. In recent years, the problem of waste tires has become very acute that there is an urgent need to find an optimal and efficient way to use scrap tires in asphalt mixtures. The previous studies showed that the utilization of crumb of tires has more effect on asphalt mixture performance, which is represented increasing in the Marshall Stability and increasing crumb of tires causes increasing in Marshall Flow and increasing in air voids content additionally more than original mixes. This paper used crumb of tires in asphalt mixture as a part of aggregate. Three sizes of the grade of crumb tires were used in asphalt mixture No. 4 (4.75 mm), No. 8 (2.36) mm and No. 50 (300µmm). Three percentages of asphalt binder (4, 5 and 6) by weight with three percentages of crumb tires (2, 4 and 8) % by weight also were used with aggregates for preparing asphalt mixture specimens. Asphalt mixture specimens were conducted according to Marshall Methods. Thirty-six specimens were equipped for evaluating Marshall Properties (Marshall Stability and flow, air voids percentage, bulk density, maximum bulk density, and Marshall Stiffness). Indirect Tensile Strength test (ITS) has been applied to obtain the cracking resistance of asphalt mixture using twenty-four specimens, which contains crumb tires. The results showed that the applying of the crumb tires has a significant performance of asphalt mixture by increasing the Marshall stability, flow, air voids, and decreasing bulk density and indirect tensile strength compared to the original mixtures.
The Effectiveness and Efficiency of Implementing Fast Set Concrete in Reparation and Reinstatement of Concrete Pavements
Authors: Tean Teoh Sze
Published: March 2021

The aim of this research is to determine the average compressive strength of fast set concrete with different formulations and their viabilities to be adopted for reparation and reinstatement works in concrete pavements especially when time is critical consideration. Fosroc’s Patchroc Rapid Setting Patch (RSP) cement was used as one of the components of the concrete. Conventionally, the recommended thickness for fast set concrete is only up to 75mm. With the technical supports from Fosroc (UK), we made a breakthrough by manipulating the design mix ratio and allow the fast set concrete remains its optimum performance with thickness up to 400mm. For the testing methodology, ten batches of concrete cube samples were produced, and each batch consists of ten numbers of samples. We are working on different mix design to determine the design with highest strength. All samples are tested in laboratory to ascertain their compressive strengths at 3 hours, 4 hours, 5 hours, 6 hours, 1 day, 3 days, 7 days, 28 days, 60 days and 90 days. Findings and analysis from several successful fast set concrete projects in Singapore Changi Airport were carried out and the data will be presented in this paper as well. Based on the most recent results, we are able to produce fast set concrete that achieve initial compressive strength more than 40MPa at 3 hours and the strength is increasing gradually with time. The projects using fast set concrete in aircraft pavement reparation and reinstatement were effective and efficient with minimum disturbance to the aircraft operation. From these results, we can conclude that fast set concrete could bring remarkable benefits and contributions to reparation and reinstatement works on operational area. This is because fast set concrete able to gain high early strength and the time for closure can be reduced drastically.
Effect of Polymer and Warm mix Modification on Asphalt Mixture Properties
Authors: Singh Bhupendra , Saboo Nikhil , Kumar Praveen
Published: March 2021

Among various kinds of asphalt binder modification methods, polymer modification and warm mix modification are two of the most popular ones. While polymer modification improves the lower and higher temperature performances of the asphalt mixture, warm mix modification reduces the mixing and compaction temperatures. So, the present study examines the effect of warm mix and polymer modification on the Marshall properties and moisture susceptibility of the asphalt mixes. In order to take advantage of both these popular modification methods, warm mix polymer modified bitumen (WMPMB) was prepared by mixing polymer and warm mix modifier in the conventional binder. The effect of the combined modification (warm mix and polymer) was studied with the help of experiments on the asphalt binders and mixtures. Based on the results it is concluded that using both the modifiers together we can avail the benefits of both the modification methods.
Blending of RAPM samples with virgin binder: a study using FTIR Spectroscopy
Authors: Bora Bhaswati , Das Animesh
Published: March 2021

In the bitumen recycling process, aged binder from reclaimed asphalt pavement material (RAPM) and virgin binder (which is added externally) get blended. The extent of blending depends on several factors. In this study, RAPM sample is kept in a pool of virgin binder and the extent of blending is studied (by taking samples from the blended binder) with the variation of temperature and RAPM size. Subsequently, the extent of blending is studied for two different RAPM samples of different ageing levels. Appropriate level of temperature and adequate mixing (by stirring) is maintained so as to create a favourable condition for blending between the aged and virgin binder to occur. After the test, the blended binder is retrieved and its chemical composition is analysed using FTIR spectroscopy, and the results are compared.
Innovative bitumen technology to reduce impact on air quality
Authors: Guwe V , Read J , Taylor R , Vasudevan J , Hanumanthgari R
Published: March 2021

With increasing environmental awareness, air quality is a topic of intense discussion and focus with many environment authorities/agencies setting targets aiming to improve air quality. Reducing the impact on air quality from road construction and maintenance activities plays a part in a holistic approach to improving air quality, particularly in the urban environment. This paper describes an innovative bitumen technology which can help reduce the impact on local air quality from bitumen and asphalt mixtures during asphalt manufacture and pavement installation. It presents laboratory experiments designed to replicate the end-to-end aspects of the bitumen supply chain; starting from refineries and storage depots to paving at road construction sites. The laboratory results have shown substantial reductions in a range of air quality indicators, such as SOx, NOx, particulate emissions, volatile organic content emission as well as in other potential nuisances such as H2S and odour. Full scale field evaluations carried out in major cities have reflected the results obtained in the laboratory and show a reduction in the emission of specific gases and particulates at various points of the asphalt preparation and pavement laying process. This bitumen technology plays a role as part of the holistic solution in improving air quality in the urban environment.
Non-Destructive Assessment of The Quality of Asphalt Laboratory Samples
Authors: Zargar M , Bullen F
Published: March 2021

In addition to instrumentation accuracy and test repeatability, the correlation of asphalt test data is very dependent on targeted “known” properties of asphalt samples or cores, such as air voids. In the case of air voids, sample preparation targets the desired sample attribute, however an assessment of the true air voids and their distribution within asphalt samples remains a challenge. Current assessment is usually via visual inspection and measuring the total air voids within the sample. However, such an approach fails to evaluate important factors such as air voids distribution and aggregate structure. In the case of testing regimes that are localised on test samples, the true air voids at the test location is essential for proper data correlation. In this study, an Ultrasonic Wave Transmission (UWT) technique was developed and applied as a non-destructive test to better assess the true localised air void properties of asphalt samples. The data correlation outcomes significantly changed the performance rankings of asphalt mixes and indicated that the UWT technique has excellent potential as a supplementary tool for evaluating asphalt laboratory samples.
Establishing stress boundaries for various loading and pavement configuration
Authors: Malhas Yazeed , Muniandy Ratnasamy , Hassim Salihudin , Jakarni Fauzan Mohd
Published: March 2021

This article is aimed to understand the relationship between stress and pavement components and finding the boundaries of the vertical and lateral stress distribution. It is carried out on four-layer pavement structure to understand the load distribution behavior through different type of materials in each layer with different resilience modulus values and different thickness. This analysis supports us to improve the pavement design accuracy and realistic, which will reduce the road maintenance cost and increase the pavement service life. Several simplifying assumptions regarding tire load applied location has been used. Therefore, 25,000 different vertical stress values in form of 125 different set of data (difference loading and pavement configuration) under five different loading conditions were analyzed using the KENPAVE software (using mechanistic empirical design method). Conclusions from the data and plot analysis show that pavement layer load distribution is affected unevenly as the effect of thickness is greater than the impact of the strength of the layer. Moreover, the results showed that there is a theoretical boundary for load distribution in the lateral direction at the bottom of the surface layer between (8 in - 14.5 in), bottom of base layer (10 in - 19.5 in) and bottom of sub-surface layer (12 in - 22 in). The stress distribution might be used as an indicator for engineers to determine the pavement behavior under an applied load.
Improve Recycled Concrete Aggregate properties in Order to Use It in Paving Application as Aggregate
Authors: Safa Eldeen Gailan Ismat , Jakarni Fauzan Mohd , Al-Attar Alyaa A. , Muniandy Ratnasamy , Hassim Salihudin
Published: March 2021

The amount of crushed cement concrete continues to increase daily as a result of the demolition of old structures, thereby increasing pollution. To cope with the pressure imposed by the rise in environmental awareness and the stringent disposal regulations set by environmental protection agencies, effective measures for handling and disposing of crushed concrete must be implemented. Instead of simply disposing of crushed concrete, alternative efforts should be considered to utilize it as a recyclable material. The objective of this study was to improve recycled concrete aggregate (RCA) to be able to using it in paving application. Three types of treatments applied to improve RCA properties. In this study three types of treatment were used to improve RCA properties. Theses treatment are soak RCA in HCL acid for 24 hours, grind RCA in Los Angeles Abrasion machine, re-grind RCA particle in jaw crush machine. In order to evaluate each treatment the aggregate properties are determined. All properties were determined for RCA passing and retained sieve size of 5 mm and 1.18 mm respectively. The calculated properties are bulk specific gravity of aggregate, absorption value, abrasion value of aggregate and angularity number of RCA. The most important conclusions are Soaking RCA in HCL acid has side effect on the specific gravity of aggregate, Putting RCA in Los Angeles Abrasion machine make RCA particles more rounded. Finally, crush RCA in jaw crusher machine for second is best way to improve RCA properties.
Toward the generation of deployable distributed IoT system on the cloud
Authors: Hassan Habeeb Ahmed , Qasha Rawaa Putros
Published: March 2021

The Internet of Things contains a number of smart devices and tools that collect and communicate sensing data, with different processing services. The diversity of IoT devices and tools in terms of the resources and the required software raises DevOp challenges for the provisioning of IoT applications. In addition, the IoT system requires a number of heterogeneous computations on the devices which form altogether with the diversity of the IoT devices new issues and challenges for the deployment of the distributed IoT applications. In this paper, we propose a new approach to generate a deployable model for the distributed IoT systems that is based on simplified, user-friendly declarative description of the smart devices’ communication, configuration, installation and computation with the IoT system parts. Our approach uses the Ansible-based YAML description for modelling and implementing the deployable IoT system on different infrastructures. The aim of this work is to minimize the efforts required to deploy the distributed IoT applications on various infrastructures including the Cloud by utilizing a simple description of the application and system components of the IoT application and environment. We motivate our work with real use case scenarios including a number of sensors, Raspberry Pi, local machine and AWS Cloud instances to show its feasibility and validity. Finally, an evaluation of our proposed approach is presented by conducting a number of experiments.
Fish dryer with heat condensor refrigerator using solar energy
Authors: Songli Yulianus , Pasau Kristiana , Kassa Agustina , Rantererung Corvis L
Published: March 2021

The fish dryer used is an innovation that utilizes the exhaust heat of the Refrigerator condensor using solar energy. The fish cooling system has an evaporator component with very low pressure and temperature so that it can absorb heat or cool the fish, while the refrigerator condensor functions to dissipate heat. The potential for condensor exhaust heat reaches a very good temperature as a source of heat energy for fish drying for fishermen. The test method is carried out on the dryer using the exhaust heat of a solar-powered refrigerator condensor as a heater in the fish drying rack space. The material in the form of dried fish is split beforehand so that the fish meat can easily release water content and dry quickly. This research was conducted by measuring the exhaust heat temperature of the Refrigerator condensor pipe which is placed in the fish drying rack space and decreasing the mass and water content of the fish. The results of this study produce a new method of utilizing the Refrigerator condensor exhaust heat that has not yet been available. The facts in the field show that the refrigerator condenser exhaust heat is very potential and effective to be used to dry fish. Drying takes place under controlled temperature, the exhaust heat from the condenser can reach 65.3 °C and dry fish reaches a moisture content of 10.50%.