19672 research outputs found
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Silver oxide nanoparticles-decorated tantala nanotubes for enhanced antibacterial activity and osseointegration of Ti6Al4V
No full textA long-term antibacterial activity of implants without compromising their biocompatibility is highly desirable to minimize the biomaterial-associated infections. Although tantalum oxide nanotubes (Ta2O5 NTs) are promising coating materials for orthodontics and orthopedics applications, their insufficient antibacterial activity retains vulnerability to post-implantation infections. This study aimed to endow antibacterial characteristics to the Ta2O5 NTs-coated Ti6Al4V substrates by decoration of silver oxide nanoparticles (Ag2O NPs). The well-adherent Ta2O5 NTs were grown via anodization of a pure tantalum (Ta) layer coated by physical vapor deposition (PVD) on the Ti6Al4V substrates. The Ag2O NPs were then decorated on the edges and walls of nanotubes through a secondary PVD under controlled conditions. The silver oxide nanoparticles-decorated tantala nanotubes (Ag2O NPs-decorated Ta2O5 NTs) promoted the formation of bone-like apatite layer and significantly reduced the viability of Escherichia coli (E. coli) cells. The prepared coating also increased the density and spreading of osteoblast cells in comparison to bare substrate. These results suggest that decorating the Ta2O5 NTs with Ag2O nanoparticles could improve antibacterial activity and the osseointegration of Ti6Al4V implants
Generation of dual-wavelength ytterbium-doped fibre laser using a highly nonlinear fibre
No full textThis paper describes the dual-wavelength operation in the 1060 nm region by applying an ytterbium-doped gain medium fiber and a highly nonlinear fiber (HNLF) as the wavelength selective filter. Due to its nonlinear properties and birefringence co-efficient, the HNLF also functions as a stabilizer for dual-wavelength fiber laser operation. Results from the experiment show that the fluctuated power of the system is less than 0.6 dB when continuously run for 20 min, indicating the system's stability. The spacing of the dual-wavelength output is obtained by fine-tuning the polarization controller within the fiber ring laser setup. The spacing ranges between 2.7 nm-21.05 nm
A facile hydrothermal approach for catalytic and optical behavior of tin oxide- graphene (SnO2/G) nanocomposite
No full textA cost-effective, facile hydrothermal approach was made for the synthesis of SnO2/graphene (Gr) nano-composites. XRD diffraction spectra clearly confirmed the presence of tetragonal crystal system of SnO2 which was maintaining its structure in both pure and composite materials' matrix. The stretching and bending vibrations of the functional groups were analyzed using FTIR analysis. FESEM images illustrated the surface morphology and the texture of the synthesized sample. HRTEM images confirmed the deposition of SnO2 nanoparticles over the surface of graphene nano-sheets. Raman Spectroscopic analysis was carried out to confirm the in-plane blending of SnO2 and graphene inside the composite matrix. The photocatalytic performance of the synthesized sample under UV irradiation using methylene blue dye was observed. Incorporation of grapheme into the SnO2 sample had increased the photocatalytic activity compared with the pure SnO2 sample. The electrochemical property of the synthesized sample was evaluated
Development of alternative dispute resolution in the Iranian construction industry
No full textThe purpose of this paper is to investigate and development of Alternative Dispute Resolution (ADR) methods in the Iranian construction industry. ADR methods were developed to acquire suitable solutions. From the research findings, despite the existence of laws for ADR methods, ADR has not been developed in Iran, and the infrastructures are not available for its development. Therefore, the Litigation process remains the main method of resolving disputes. If ADR is developed, it can be effective in resolving disputes in the construction industry and yield positive results. The potential of binding methods of ADR for dispute resolution in the construction industry is about 2.25 times that of non-binding methods. Mixed Method and Concurrent Triangulation Strategy have been used to carry out the investigations. The qualitative data collected for this research was through semi-structured interviews with 30 experts, and the quantitative data was collected through questionnaires with 112 experts
Exoskeleton robot control for synchronous walking assistance in repetitive manual handling works based on dual unscented Kalman filter
No full textProlong walking is a notable risk factor for work-related lower-limb disorders (WRLLD) in industries such as agriculture, construction, service profession, healthcare and retail works. It is one of the common causes of lower limb fatigue or muscular exhaustion leading to poor balance and fall. Exoskeleton technology is seen as a modern strategy to assist worker’s in these professions to minimize or eliminate the risk of WRLLDs. Exoskeleton has potentials to benefit workers in prolong walking (amongst others) by augmenting their strength, increasing their endurance, and minimizing high muscular activation, resulting in overall work efficiency and productivity. Controlling exoskeleton to achieve this purpose for able-bodied personnel without impeding their natural movement is, however, challenging. In this study, we propose a control strategy that integrates a Dual Unscented Kalman Filter (DUKF) for trajectory generation/prediction of the spatio-temporal features of human walking (i.e. joint position, and velocity, and acceleration) and an impedance cum supervisory controller to enable the exoskeleton to follow this trajectory to synchronize with the human walking. Experiment is conducted with four subjects carrying a load and walking at their normal speed- a typical scenario in industries. EMG signals taken at two muscles: Right Vastus Intermedius (on the thigh) and Right Gastrocnemius (on the calf) indicated reduction in muscular activation during the experiment. The results also show the ability of the control system to predict spatio-temporal features of the pilots’ walking and to enable the exoskeleton to move in concert with the pilot
Do Shariah-compliant Companies Engage Lesser Earnings Management Behaviour?
No full textResearch aims: This study aims to understand how reputation, financial distress and financial performance influence Shariah-compliant companies into engaging earnings management behaviour. The financial data of 69 FTSE Bursa Malaysia 100 Index companies, dating 2010 to 2014 (five years), were analysed. Design/Methodology/Approach: This study uses the Modified Jones model (Jones, 1991; Dechow, Sloan, & Sweeney, 1996), Roychowdhury’s model (2006) to examine earnings management behaviour of Shariah-compliant companies. Research findings: The results of this study suggest that company’s reputation, financial distress and financial performance are factors that can influence company’s earnings management behaviour and that Shariah values are ineffective in deterring the management from earnings management behaviour. Theoretical contribution/Originality: The findings of this study contribute to the literature by showing that Shariah values may not be beneficial in shaping good business management and reporting practices. Practitioner/Policy implications: The alarming results drawn from this study is a reason for policy setters and relevant accounting bodies to give more emphasis on developing better accounting and reporting policies. Research limitation: This study is limited to non-financial sectors due to measurement limitations
Highly sensitive selectively coated photonic crystal fiber-based plasmonic sensor
No full textHighly sensitive and miniaturized sensors are highly desirable for real-time analyte/sample detection. In this Letter, we propose a highly sensitive plasmonic sensing scheme with the miniaturized photonic crystal fiber (PCF) attributes. A large cavity is introduced in the first ring of the PCFs for the efficient field excitation of the surface plasmon polariton mode and proficient infiltration of the sensing elements. Due to the irregular air-hole diameter in the first ring, the cavity exhibits the birefringence behavior which enhances the sensing performance. The novel plasmonic material gold has been used considering the chemical stability in an aqueous environment. The guiding properties and the effects of the sensing performance with different parameters have been investigated by the finite element method, and the proposed PCFs have been fabricated using the stack-and-draw fiber drawing method. The proposed sensor performance was investigated based on the wavelength and amplitude sensing techniques and shows the maximum sensitivities of 11,000 nm/RIU and 1;420 RIU−1, respectively. It also shows the maximum sensor resolutions of 9.1 × 10−6 and 7 × 10−6 RIU for the wavelength and amplitude sensing schemes, respectively, and the maximum figure of merits of 407. Furthermore, the proposed sensor is able to detect the analyte refractive indices in the range of 1.33–1.42; as a result, it will find the possible applications in the medical diagnostics, biomolecules, organic chemical, and chemical analyte detection
Educational intervention on delirium assessment using confusion assessment method-ICU (CAM-ICU) in a general intensive care unit
No full textAims and Objectives: To assess intensive care unit nurses’ knowledge of intensive care unit delirium and delirium assessment before and after an educational intervention. In addition, nurses’ perception on the usefulness of a delirium assessment tool and barriers against delirium assessment were assessed as secondary objectives. Background: Early identification of delirium in intensive care units is crucial for patient care. Hence, nurses require adequate knowledge to enable appropriate evaluation of delirium using standardised practice and assessment tools. Design: This study, performed in Malaysia, used a single-group pretest–posttest study design to assess the effect of educational interventions and hands-on practices on nurses’ knowledge of intensive care unit delirium and delirium assessment. Methods: Sixty-one nurses participated in educational intervention sessions, including classroom learning, demonstrations and hands-on practices on the Confusion Assessment Method-Intensive Care Unit. Data were collected using self-administered questionnaires for the pre- and postintervention assessments. Analysis to determine the effect of the educational intervention consisted of the repeated-measures analysis of covariance. Results: There were significant differences in the knowledge scores pre- and postintervention, after controlling for demographic characteristics. The two most common perceived barriers to the adoption of the intensive care unit delirium assessment tool were “physicians did not use nurses’ delirium assessment in decision-making” and “difficult to interpret delirium in intubated patients”. Conclusions: Educational intervention and hands-on practices increased nurses’ knowledge of delirium assessment. Teaching and interprofessional involvements are essential for a successful implementation of intensive care unit delirium assessment practice. Relevance to Clinical Practice: This study supports existing evidences, indicating that education and training could increase nurses’ knowledge of delirium and delirium assessment. Improving nurses’ knowledge could potentially lead to better delirium management practice and improve ICU patient care. Thus, continuous efforts to improve and sustain nurses’ knowledge become relevant in ICU settings
Analysis of surface cracks in round bars using dual boundary element method
No full textA closed-form solution for stress intensity factors (SIFs) of a semi-elliptical surface crack in round bars subjected to torsional loading using the dual boundary element method are presented in this paper. The SIFs of surface cracks having different crack aspect ratios and inclination angles were calculated using the numerical software BEASY. In general, the results revealed that the Mode III SIF was strongly affected by both the crack size and crack shape whereas that crack aspect ratio had the greatest influence on the SIFs regardless of the fracture modes
Effect of microwave sintering on the properties of copper oxide doped Y-TZP ceramics
No full textThe effect of various amounts of copper oxide (CuO) up to 1 wt% on the densification behaviour and mechanical properties of 3 mol% yttria-tetragonal zirconia polycrystal (Y-TZP) were studied by using microwave (MW) sintering method. The MW sintering was performed at temperatures between 1100 °C and 1400 °C, with a heating rate of 30 °C/min. and holding time of 5 min. The beneficial effect of MW in enhancing densification was also compared for the undoped and 0.2 wt% CuO-doped Y-TZP when subjected to conventional sintering (CS) method. The results showed that significant enhancement in the relative density and Vickers hardness were observed for the undoped Y-TZP when MW-sintered between 1100 °C and 1250 °C. It was revealed that the 0.2 wt% CuO-doped Y-TZP and MW sintered at 1250–1300 °C could attain ≥ 99.8% of theoretical density, Vickers hardness of about 14.4 GPa, fracture toughness of 7.8 MPam1/2 and exhibited fine equiaxed tetragonal grain size of below 0.25 µm. In contrast, the addition of 1 wt% CuO was detrimental and the samples exhibited about 50% monoclinic phase upon sintering coupled with poor bulk density and mechanical properties. The study also revealed that the addition of 0.2 wt% CuO and subjected to conventional sintering produced similar densification as that obtained for microwave sintering, thus indicating that the dopant played a more significant role than the sintering method