520 research outputs found

    Stabilisation and solidification of contaminated soil using cement and sugarcane bagasse ash (SCBA)

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    Soil that is contaminated with heavy metals has become a major issue worldwide. However, proper remediation techniques such as stabilisation/solidification (S/S) method can be employed and is capable of controlling these heavy metals. Conventionally, the common S/S method used cement as binder on remediating the contaminated soil particularly heavy metals. This research is to investigate the effect of physical and leachability of contaminated soil in S/S method when Sugarcane Bagasse Ash (SCBA) is added to remedy contaminated soil. Landfill contaminated soil was used to test the effectiveness of those binder. Cement was added at a proportion of 5%, 10%, 15% and 20% in sample weights without SCBA while in another sample; the cement was replaced by SCBA at a proportion of 2.5%, 5%, 7.5% and 10%. All samples are to be allowed to harden and cured at room temperature for 7, 14 and 28 days. The effectiveness of the treatment was assessing by conducting physical testing such as Unconfined Compression Strength, Water Absorption and Permeability test. In addition, leaching tests were performed to identify the leachate behavior of heavy metals during treatment. Three leaching tests were conducted and they were the Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP) and Dynamic Leaching Test (DLT). Through the physical testing, samples containing 10% OPC mixed with 10% SCBA were found to improve the compressive strength, reduced the water absorption and water permeability measuring 1550 MPa, 17.94% and 4.41 x 10 -10 m/s respectively. In the same way, through the statistical analysis, the R-squared for UCS with respect to mixed design is high at 98%. However, the value for both water absorption and permeability recorded to be marginally low, compared to the value for strength at 89% and 88% respectively. Through the TCLP and SPLP test, results indicated that when SCBA added to OPC content in soil samples, less heavy metal been leached out from the S/S sample. In average, the satisfying result was shown by samples containing 10% OPC + 10% SCBA where reduction of heavy metals in final leachate is more than 90% for As, Cd, Cr, Pb and Zn. Through the Dynamic Leaching Test, sample containing 10% OPC +10% SCBA showed the satisfactory leachability index (Lx) at 9.17, 9.17, 8.81, 8.17 and 6.97 for As, Cd, Cr, Pb and Zn respectively. This indicates that the use of cement and SCBA as a binder was successful in remediating the contaminated soils through the S/S method

    Deposition and comparative wear study of thin film coatings

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    As a part of a group project a magnetron deposition system was designed, constructed and commissioned for producing thin film coatings. Deposition of molybdenum nitride films has been carried out using reactive magnetron sputtering for characterization. The films were characterized in terms of their thickness, hardness and adhesion. The films were reasonably hard but poorly adherent to the steel flats. A wear test rig designed, constructed and commissioned by another research student to carry out impact wear tests was adapted for adhesive wear tests. Progressive wear tests have been done on titanium carbide (5% titanium) coated, titanium nitride coated and uncoated specimens of four substrate materials. The substrate materials are: i) D2 tool steel, ii) D3 tool steel, iii) Vanadis 4 and iv) Vanadis 10. Titanium carbide coatings proved to have good wear resistance but titanium nitride coatings did not. Different coatings imparted different wear resistance to the substrate. The substrate materials have a profound effect on the wear resistance of the coated surfaces

    Authentic assessment: An instructional tool to enhance students learning

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    This paper underscores the process of using authentic assessment as a learning tool in a school the context of Pakistan. Data was collected through classroom observations, conducting interviews, analyzing relevant documents and maintaining person reflective diary. Findings indicate desirable changes in the perception as well as practices of teachers and students. Replacement of traditional paper-pencil test with authentic assessment resulted in active participation of teachers and students in teaching and learning process. Study finding also reveal considerable improvement in high order skills of the students. They were actively engaged in planning, collecting information and disseminating it to the community. Use of rubric for assessment was found to be very effective in determining a pathway for both the teachers and the students to look for and get to the desirable results

    Corporate social responsibility disclosures and earnings quality: Are they a reflection of managers’ opportunistic behavior?

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    Purpose – This paper aims to explore the relationship between corporate social responsibility (CSR) disclosures and earnings quality proxied by earnings accruals. Specifically, we examine whether CSR disclosures are context-specific, that is, whether companies dominated by powerful stakeholders are obliged to behave in a responsible manner to constrain earnings management, thereby reporting higher-quality earnings to investors. Design/methodology/approach – This paper explores the relationship between CSR disclosures and earnings quality proxied by earnings accruals. Specifically, we examine whether CSR disclosures are context-specific, that is, whether companies dominated by powerful stakeholders are obliged to behave in a responsible manner to constrain earnings management, thereby reporting higher-quality earnings to investors. Findings – Results show that managers in an emerging economy manage earnings when they provide more CSR disclosures. Such earnings management is achieved through income increasing discretionary accruals. Furthermore, companies from export-oriented industries dominated by powerful stakeholders (international buyers) disclosing more CSR activities, provide transparent financial reports through constraining earnings management. Originality/value – The findings of this study are significant for both investors and policymakers. Investors should not take for granted that firms engage in CSR activities, behave ethically and provide transparent financial reports. As we document that firms might manipulate earnings through discretionary accruals and provide less transparent financial reports to shareholders, the credibility of firms’ CSR policies should be assessed with caution. Policies directing at promoting socially responsible practices instead of motivating the desired behaviour, may provide managers with additional incentives to utilise CSR for opportunistic behaviour. Thus, policymakers need to be cautious about this opportunistic behaviour and enhance monitoring to enforce social compliance. Possibly, some guidelines can be introduced to confirm that CSR disclosures are based on actual practice and not just a “green wash” statement to deceive stakeholders

    Printed Wide Slot Ultra-Wideband Antenna

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    Recent Trends in Printed Ultra-Wideband (UWB) Antennas

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    Prioritizing the effective factors for customers attraction: A case study of Sepah Bank

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    During the past few years, privatization has recently changed banking industry and there has been an increase competition in this industry. New banks try to present better services to absorb customers and traditional banks attempt to improve their services to retain their existing customers. In such environment and with limited amount of resources, there is a necessity to prioritize different influencing factors on the quality of the services. The proposed study of this paper presents a multi criteria decision making method along with Kano method to prioritize the most influencing factors of service quality. The proposed study of this paper is implemented for one of the oldest banks in Iran called Sepah. We have gathered different factors influencing customer satisfaction for all Sepah banks located in Semnan, Iran and using, analytical hierarchy process we provide a detailed ranking

    Adaptive routing in packet-switched networks using agents updating methods

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    This paper investigates a non-trivial, multi-objective and multi-constraint routing optimisation problem for dynamic packet-switched networks. The research adopts the application of the ant colony optimisation process into routing and congestion control in telecommunication networks. This paper suggests the use of epochal updating in conjunction with modified incremental updating to update the routing table in each switching node. The resulting new approach is called the For/Backward approach. Three updating methods (Forward, Backword, For/Backword) are simulated over a packet-switched network, representing Malaysian Backbone Network, using different combinations of traffic and geographical traffic patterns. The simulation results show a clear improvement on network performance (less average packet delay and greater throughput) using the For/Backward approach compared to the Forward and Backward methods. Furthermore, the behavior of the Forward and Backward methods is studied for inconsistency of behavior

    Diagnosis of genetic defects by chromosomal analysis

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    Of 901 karyotypes performed over a period of 4 years, genetic anomalies were detected in 162 cases. Down’s syndrome (trisomy 21) was the most common (168.8%) genetic disorder followed by Turner’s syndrome, Philadelphia chromosome, Klinefelter\u27s syndrome, Edward’s syndrome (trisomy 18) and Patau’s syn­drome (trisomy 13). All the three trisomies were detected very early in life. Mean age at the time of diagnosis for Turner’s syndrome was 13.3 years, allowing a timely hormone replacement therapy to improve secondary sexual characters. Patients with Klinefelter\u27s syndrome were diagnosed late (mean age 23.6 years), which greatly reduced their chances of an effective therapy to improve the clinical and social outcome (JPMA 45:295,1995)

    Development and validation of a reversed-phase column liquid chromatographic method for simultaneous determination of two novel gliptins in their binary mixtures with Metformin

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    A new, simple, accurate, and precise liquid chromatographic method has been developed and validated for the determination of two novel dipeptidylpeptidase-4 (DPP-4) inhibitors; namely vildagliptin (VLG) and saxagliptin HCl (SXG) simultaneously in their binary mixtures with metformin HCl (MET). Chromatographic separation was achieved on an Inertsil® CN-3 column (250 mm x 4.6 mm, 5 µm). Isocratic elution using a mobile phase of potassium dihydrogen phosphate buffer pH (4.6) - acetonitrile (15:85, v:v) at a flow rate of 1 mL/min with UV detection at 208 nm was performed. The liquid chromatographic method was used for the simultaneous determination of either VLG, SXG and MET in the range of 5-200, 0.5-20 and 50-2000 μg/mL, respectively. The methods developed were satisfactorily applied to the analysis of the pharmaceutical formulations and proved to be specific and accurate for the quality control of the cited drugs in pharmaceutical dosage forms
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