This study discusses the mechanical properties of concrete using annealed wire fiber which includes compressive strength, splitting tensile strength and flexural strength. The composition of the fiber used is 0.75% of...
This study discusses the mechanical properties of concrete using annealed wire fiber which includes compressive strength, splitting tensile strength and flexural strength. The composition of the fiber used is 0.75% of the volume of concrete with a diameter of 0.8 mm fiber and the length of the fiber varied 36 mm, 48 mm and 60 mm or aspect ratio L/d of 45, 60 and 75. Test specimens used in this study are cylinders measuring 100 mm x 200 mm as many as 24 pieces and beam measuring 100 mm x 100 mm x 400 mm as many as 12 pieces. The test was performed after 28 days of concrete with the UTM tool using ASTM C-39, C-496 and C-78 standard for compressive strength test, splitting tensile strength test and flexural strength test. The result of this research shows that there is an increase of mechanical properties of concrete for compressive strength of 3.75% to 33.56%, a tensile strength of 3.35% to 32.62% and flexural strength of 9.94% to 42.14%. For maximum compressive strength for 48 mm fiber length while tensile strength and maximum flexural strength for 60 mm fiber length.
Probing of a question between two methodologies of the multiplicative model of Time Series and Fuzzy Relation is challenging to answer, without exploring each of both theories. This paper aims to discern any discrepan...
Probing of a question between two methodologies of the multiplicative model of Time Series and Fuzzy Relation is challenging to answer, without exploring each of both theories. This paper aims to discern any discrepancies or similarities in them, since each has detailed items that could lead to practical advantages to proceed on forecasting or decision making. Pseudo coding is a chance to explore theories and to surface those practical advantages. The finding states that the multiplicative model of time series factually has components that could have dependencies one to another, and the fuzzy relations help to map each point along their processes to determine how much dependency contained in the system that could conclude of a decision making.
This paper presents the determination of tensile, flexural, and acoustical properties of short oil palm frond (OPF) fibre reinforced polyester composites and issues that have to be controlled in order to improve those...
This paper presents the determination of tensile, flexural, and acoustical properties of short oil palm frond (OPF) fibre reinforced polyester composites and issues that have to be controlled in order to improve those properties. Three composite samples were fabricated using fibre content of 5%, 10% and 15% (by mass fraction) each. The tensile strength and elastic modulus of the composites were determined by tensile test conforming to the ASTM D638 standard and the flexural strength was measured by the three-point bending test method in accordance to ASTM D790 standard whereas the acoustical properties were determined by transfer function method conforming to the ISO 10534-2 standard. It is showed that the OPF-polyester composites possess greater tensile strength and flexural strength at lower fibre content while the elastic modulus registered increment with higher fibre loadings. Reduction in tensile and flexural strengths at higher fibre content is caused by poor stress transfer mechanism as the combined effect of inadequate fibre/matrix interface adhesion and stress concentration spots. Fibre agglomeration, which causes hindrance to the polyester macromolecule chain mobility, is accounted for the increment in stiffness properties as the amount of fibre is increased. From the measurement of the acoustical properties shows that the sound absorption coefficient is a function of incidence frequency. The normal incidence sound absorption coefficients for different frequencies tend to increase with increasing frequency operation. There is an excellent agreement between the absorption coefficient and the input frequency.
Nickel oxide (NiO)-based supercapacitor electrodes have attracted great attention due to the ultra-high theoretical specific capacitance. NiO, as a typical pseudocapacitive, is considered to be the most promising cand...
Nickel oxide (NiO)-based supercapacitor electrodes have attracted great attention due to the ultra-high theoretical specific capacitance. NiO, as a typical pseudocapacitive, is considered to be the most promising candidate as an electrode material for supercapacitors. Herein, the NiO nanostructures directly grown on the Ni foam have been successfully designed and synthesized via the hydrothermal method. The optimal Ni foam/NiO electrode exhibits a high specific capacity of 93.2 C/g at a current density of 5 mV/s. The enhanced electrochemical performance of Ni foam/NiO electrodes is due to the unique morphological architecture which facilitates open access and promotes electrolyte ion/electron transport.
Biomass is an organic substance widely available in nature as a fresh or a waste material considered renewable energy that aligns with the zero-carbon scheme to reduce the dependency on fossil fuels. However, after co...
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Biomass is an organic substance widely available in nature as a fresh or a waste material considered renewable energy that aligns with the zero-carbon scheme to reduce the dependency on fossil fuels. However, after conversion, biomass's physical or chemical properties highly affect biofuel characteristics. A variety of instruments can be used to figure out biofuel reactivity. Considering commonly adopted instruments, thermogravimetric analysis (TGA) is a simple, fast, and efficient way to determine biofuel properties and reactivity. The TGA method has the capability to analyze the biofuel properties (proximate analysis: moisture, volatile matter, fixed carbon, and ash) and combustion features of biomass (such as ignition, reactivity, etc). Most importantly, the TG curvatures (TGA and DTG) reveal the behavior of the biofuel during the thermodegradation process. As a consequence, the quality and quantity analyses on the biofuel properties and reactivity can be investigated comprehensively. Moreover, some TGA integration with artificial intelligence (AI) has been studied to better understand biofuel management and technology for future development. The outcome for the TGA-AI integration may obtain an excellent result with the fit quality value R 2 >95 %. This study aims to comprehensively review relevant research using TGA to analyze the lignocellulosic biofuel properties and reactivity. Moreover, the discussion in this study is extended to perspective, challenges, and future work.
Asynchronous Brain Computer Interfaces (BCI) al-low system activation at free will. This scenario would be desirable for potential users such as patients with motor disabilities, however, there are still several limit...
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ISBN:
(数字)9781728185262
ISBN:
(纸本)9781728185279
Asynchronous Brain Computer Interfaces (BCI) al-low system activation at free will. This scenario would be desirable for potential users such as patients with motor disabilities, however, there are still several limitations such as long calibration times and overall performance. Different approaches to improve these systems explore diverse linear electroencephalography (EEG) features in order to describe cognitive states. Alternatively, the present study proposes the use of recurrence quantification analysis (RQA), which provides indices about the dynamical behaviour of non-linear systems. We evaluated the accuracy of continuous detection of mental calculation and idle state using RQA features from EEG recordings. Among the different classification methods that were tested, random forest (RF) classifier resulted in the best performance. From 35 selected RQA features, 12 healthy subjects achieved mean accuracy of 0.924 ±0.048, whereas with 150 selected features mean accuracy was 0.977 ±0.020. These results suggest that RQA features are adequate for continuous task episode detection in asynchronous BCI. However, a restriction in the number of these features, conceived for improving computational costs and time, does impact detection performance.
Acute lung injury (ALI) is a life-threatening condition with limited treatment options. The pathogenesis of ALI involves macrophage-mediated disruption and subsequent repair of the alveolar barriers, which ultimately ...
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Assessment of water pollution is a critical study because it can affect humans directly. Likewise, river water is widely used for various daily needs. It is important to group rivers according to their classes so that...
Assessment of water pollution is a critical study because it can affect humans directly. Likewise, river water is widely used for various daily needs. It is important to group rivers according to their classes so that further analysis and action can be carried out. This article discusses the clustering of rivers in several areas in the southeast part of Central Java Province consisting of 14 sampling stations based on several water quality parameters. The pollutant parameters include TSS, electrical conductivity, pH, BOD, COD, and DO. The method used is Hierarchical clustering in which the object grouping begins with grouping two objects with the closest distance being combined into one cluster, and then continues until one cluster is formed consisting of all objects. The results show that five clusters are the ideal choice. Except for electrical conductivity, the parameters observed are dominantly the difference between clusters. Through the formation of river clusters based on their water quality, the characteristics of each cluster and cluster members with high similarity can be identified.
Fresh water is needed in industrial activities. For these needs sea water is usually used as raw material if the plant is near the sea and far from the river. SWD (sea water desalination) is used to process sea water ...
Fresh water is needed in industrial activities. For these needs sea water is usually used as raw material if the plant is near the sea and far from the river. SWD (sea water desalination) is used to process sea water to fresh water, that is by reducing levels of salinity or reducing levels of total dissolved solid (TDS). There are two technologies in SWD, namely thermal distillation and reverse osmosis (RO) membrane technology. Residual SWD process or also called blowdown water has high salinity levels can be converted into electrical energy through SGP (salinity gradient power). There are two technologies to capture energy from salinity differences, namely PRO (Pressure Retarded Osmosis) and RED (Reverse Electrodialysis). PRO and RED are renewable energy technology, there are no emision, no moving part, abundant availability in nature and can be recycled. In this article, an analysis for SWD of oil refinery is carried out. From the analysis results it is known that the plant uses thermal distillation technology, requires power as 64.25 MW and 3,403 m3/h seawater to produce 242 m3/h freshwater. With SGP, the potential recovery of power gained is 0.786 MW. This recovery potential is still too small when compared to energy requirements of SWD with thermal distillation technology, but if it use RO technology that only requires 3.6-5.7 kWh/m3 or 0.87 - 1.40 MW to produce 242 m3/h, a significant impack to saving energy will be obtained.
The purpose of this study was to examine the relationship between vehicle distance (gap) formed by the vehicle volume. For this reason, in this study, there were 16 (sixteen) roads that were used as objects of researc...
The purpose of this study was to examine the relationship between vehicle distance (gap) formed by the vehicle volume. For this reason, in this study, there were 16 (sixteen) roads that were used as objects of research. To get the values from the gap variable, the VISSIM software is used in the data processing. In the use of this software calibration and validation are done by trial and error to produce simulation results that can replicate the actual traffic conditions. The results of this study indicate that statistically from the coefficient of determination and F test conducted concluded that there is a significant relationship between vehicle volume and gap.
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