188 research outputs found
Penerapan Interactive Multimedia untuk Perangkat Ajar Persiapan Toefl Berbahasa Indonesia
One of added values to compete in work and business is mastering English\u27s Language. To support the needs of an online teaching tool that can be accessed anywhere and is easy to use, an online teaching tool that uses Indonesian is made with an attractive multimedia display so that users do not feel bored and can monitor the development of the value achieved. The material presented is based on the structure tested in TOEFL. The method used in designing these applications is the waterfall method, ranging from data collection through questionnaires and comparative analysis of similar applications and then proceed with the design and development of applications and user satisfaction evaluation. It is expected that these applications can help in improving the English language proficiency as measured by TOEFL score achieved
Identifying The Potential Sources of Chemical Elements in Drainage and Rivers Using Google Earth Imageries and Posteriori Knowledge
This study attempts to identify the potential sources of the chemical elements in the river and drainage water using in-situ water quality sampling and public domain satellite data. Monitoring the physico-chemical level of urban streams and rivers is important to secure sufficient water resources, an indicator to the ecological degradation in urban areas and an indicator of environmental pollution. Nonetheless, identifying the potential sources of chemical pollutants by field observation is constrained by hard labor activities, time, and cost. Having satellite imagery that provides land use activity information would be useful in determining the chemical sources. Therefore, the objective of this paper is to utilize the publicly accessible Google satellite images in identifying the potential sources of the chemical elements' presence in the water that is physically sampled and measured over the selected urban rivers and drainage of Johor Bahru. Three chemical elements were identified, ammonia (NH3), nitrate (NO3-), and phosphate (PO43-). The identification of the chemical sources is conducted based on the interpretation of the satellite-derived information together with the posteriori knowledge, experience, and inputs in an environmental chemistry perspective. The findings revealed that the proportion of land used did not always have a significant impact on the chemical content of the waterways. For ammonia, areas with significant hotspots (aquaculture, wet market) are more significant, although the size of the area is not dominant. The nitrate content, on the other hand, showed quite a distinct pattern linked to oil palm, intensive farming, and industrial or commercial areas. There was no distinct land use pattern associated with phosphate level. However, locations with high residential areas were likely to have high phosphate content in their respective waterways or drainage to the onsite investigations with minimal labor works, cost effective, and time efficient
Production of Biocellulosic Ethanol from Wheat Straw
Wheat straw is an abundant lignocellulosic feedstock in many parts of the world, and has been selected for producing ethanol in an economically feasible manner. It contains a mixture of sugars (hexoses and pentoses).Two-stage acid hydrolysis was carried out with concentrates of perchloric acid, using wheat straw. The hydrolysate was concentrated by vacuum evaporation to increase the concentration of fermentable sugars, and was detoxified by over-liming to decrease the concentration of fermentation inhibitors. After two-stage acid hydrolysis, the sugars and the inhibitors were measured. The ethanol yields obtained from by converting hexoses and pentoses in the hydrolysate with the co-culture of Saccharomyces cerevisiae and Pichia stipites were higher than the ethanol yields produced with a monoculture of S. cerevisiae. Various conditions for hysdrolysis and fermentation were investigated. The ethanol concentration was 11.42 g/l in 42 h of incubation, with a yield of 0.475 g/g, productivity of 0.272 gl ·h, and fermentation efficiency of 92.955 %, using a co-culture of Saccharomyces cerevisiae and Pichia stipite
Identifying The Potential Sources of Chemical Elements in Drainage and Rivers Using Google Earth Imageries and Posteriori Knowledge
This study attempts to identify the potential sources of the chemical elements in the river and drainage water using in-situ water quality sampling and public domain satellite data. Monitoring the physico-chemical level of urban streams and rivers is important to secure sufficient water resources, an indicator to the ecological degradation in urban areas and an indicator of environmental pollution. Nonetheless, identifying the potential sources of chemical pollutants by field observation is constrained by hard labor activities, time, and cost. Having satellite imagery that provides land use activity information would be useful in determining the chemical sources. Therefore, the objective of this paper is to utilize the publicly accessible Google satellite images in identifying the potential sources of the chemical elements' presence in the water that is physically sampled and measured over the selected urban rivers and drainage of Johor Bahru. Three chemical elements were identified, ammonia (NH3), nitrate (NO3-), and phosphate (PO43-). The identification of the chemical sources is conducted based on the interpretation of the satellite-derived information together with the posteriori knowledge, experience, and inputs in an environmental chemistry perspective. The findings revealed that the proportion of land used did not always have a significant impact on the chemical content of the waterways. For ammonia, areas with significant hotspots (aquaculture, wet market) are more significant, although the size of the area is not dominant. The nitrate content, on the other hand, showed quite a distinct pattern linked to oil palm, intensive farming, and industrial or commercial areas. There was no distinct land use pattern associated with phosphate level. However, locations with high residential areas were likely to have high phosphate content in their respective waterways or drainage to the onsite investigations with minimal labor works, cost effective, and time efficient
Statistical Approach to the Cellulose Nanocrystal Tribological Behavior on the Piston Liner Contact Using Full Factorial Design (FFD)
The primary goal of this research is to investigate the effect of tribo-test parameters on the coefficient of friction (COF) and wear rate of the cylinder liner and piston ring pair. The tribological studies are carried out utilizing a full factorial design (FFD) experimental scheme. Sliding speed, temperature, volume concentration, and applied force were all evaluated as important parameters that determine tribological qualities. The effects of various variables and their interactions on the dependent variables were investigated. The ANOVA analysis demonstrates that the applied load could be the most influential factor affecting the minimum amount of the friction coefficient. The minimum quantity of wear rate indicates that as the sliding speed increases, the wear rate decreases
The effect of pre-damaged level on repair damaged columns by using steel straps tensioning technique
To date, repair of damaged columns has become increasingly more significant. The failure of columns structure contributes to the serious consequences in structural stability. Most of the existing repairing techniques are based on lateral passive confining pressu re. However, this passive-type of confinement is ineffective in restoring the performance of damaged concrete columns. In this regards, active confinement was selected in this study to repair damaged concrete columns which can actively confine concrete in this study. Ste el strapping tensioning technique (SSTT) allows pre-tensioning low-cost recycled steel straps around the damaged column was chosen herein to represent active confinement. A total of 12 columns were prepared and loaded axially to certain degree of their respective ultim ate strength. Hence, a pre-damage level of the columns was developed. Then, the damaged columns repaired by using mortar and confined with SSTT. Finally, the repaired columns were then tested under monotonic uniaxial load. The structural performances of the confined repaired columns were compared with those of the repaired columns without confinement. It is expected that as the concrete compressive strength increases, the effectiveness in restoring the load carrying capacity of the damaged column becomes more significant
Effect of pre-tensioned level on axial stress-strain behaviour of confined concrete: A review
External passive confinement has been used as strengthening scheme to rehabilitate existing reinforced concrete buildings. Passive confinement requires a certain lateral dilation of concrete prior to the activation of the confining effect. Applying pre -tensioned force to the confining material can eliminate the needs of such lateral dilation. This paper presents a review on previous studies conduct ed about pretensioned level in confined concrete. A short discussion is done based on the effect of pre -tensioned level to the three regions of stressstrain curve. It was found that pre-tensioned level affects the stress-strain behaviour of confined concrete. Pre-tensioned level that is too high decreases the strain capacity of the confined concrete. This review suggests that there exists an optimum pre-tensioned level for each confining material
Prediction and Optimization of Thermophysical Properties of Hybrid Cellulose Nanocrystal-Copper (II) Oxide Nanolubricant for Tribology Application
Response surface methodology (RSM) was used in conjunction with the miscellaneous design model to identify prediction models for the thermophysical properties of a hybrid cellulose nanocrystal-copper (II) oxide nanolubricant. Minitab 18 statistical analysis software and Response Surface Methodology (RSM) based on Central Composite Design (CCD) were utilised to generate an empirical mathematical model investigating the effect of concentration and temperature. Analysis of variance (ANOVA) is used to validate the significance of the developed empirical mathematical model. Thirteen experiments were conducted to obtain second-order polynomial equations for the desired specific heat capacity, thermal conductivity, and dynamic viscosity, outputs. The predicted values were found to be in reasonable agreement following the investigational finding. In addition, the models could predict more than 80% of the nanolubricant output variations, indicating that the model is accurate. In the optimization plot, the predicted optimal values for dynamic viscosity, thermal conductivity, and specific heat capacity are 2.3631, 0.1463, and 1.6311, respectively. The relevant parameters are 90 °C and 0.1 for temperature and concentration, respectively. The plotted composite is 0.6531. The findings of the percentage of absolute error (POAE) reveal that the model may precisely predict the optimum experimental parameters
The alpha 7 nicotinic receptor agonist PHA-543613 hydrochloride inhibits <i>Porphyromonas gingivalis</i>-induced expression of interleukin-8 by oral keratinocytes
Objective:
The alpha 7 nicotinic receptor (α7nAChR) is expressed by oral keratinocytes. α7nAChR activation mediates anti-inflammatory responses. The objective of this study was to determine if α7nAChR activation inhibited pathogen-induced interleukin-8 (IL-8) expression by oral keratinocytes.<p></p>
Materials and methods:
Periodontal tissue expression of α7nAChR was determined by real-time PCR. OKF6/TERT-2 oral keratinocytes were exposed to <i>Porphyromonas gingivalis</i> in the presence and absence of a α7nAChR agonist (PHA-543613 hydrochloride) alone or after pre-exposure to a specific α7nAChR antagonist (α-bungarotoxin). Interleukin-8 (IL-8) expression was measured by ELISA and real-time PCR. Phosphorylation of the NF-κB p65 subunit was determined using an NF-κB p65 profiler assay and STAT-3 activation by STAT-3 in-cell ELISA. The release of ACh from oral keratinocytes in response to <i>P. gingivalis</i> lipopolysaccharide was determined using a GeneBLAzer M3 CHO-K1-blacell reporter assay.<p></p>
Results:
Expression of α7nAChR mRNA was elevated in diseased periodontal tissue. PHA-543613 hydrochloride inhibited <i>P. Gingivalis</i>-induced expression of IL-8 at the transcriptional level. This effect was abolished when cells were pre-exposed to a specific α7nAChR antagonist, α-bungarotoxin. PHA-543613 hydrochloride downregulated NF-κB signalling through reduced phosphorylation of the NF-κB p65-subunit. In addition, PHA-543613 hydrochloride promoted STAT-3 signalling by maintenance of phosphorylation. Furthermore, oral keratinocytes upregulated ACh release in response to <i>P. Gingivalis</i> lipopolysaccharide.<p></p>
Conclusion:
These data suggest that α7nAChR plays a role in regulating the innate immune responses of oral keratinocytes.<p></p>
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