Studies on influence of hydrogen and carbon monoxide concentration on reduction progression behavior of molybdenum oxide catalyst

Temperature programmed reduction (TPR) analysis was applied to investigate the chemical reduction progression behavior of molybdenum oxide (MoO₃) catalyst. The composition and morphology of the reduced phases were characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM). The reduction progression of MoO₃ catalyst was attained with different reductant types and concentration (10% H₂/N₂, 10% and 20% CO/N₂ (%, v/v)). Two different modes of reduction process were applied. The first approach of reduction involved non-isothermal mode reduction up to 700 °C, while the second approach of reduction involved the isothermal mode reduction for 60 min at 700 °C. Hydrogen temperature programmed reduction (H₂-TPR) results showed the reduction progression of three-stage reduction of MoO₃ (Mo⁶⁺ → Mo⁵⁺ → Mo⁴⁺ → Mo⁰) with Mo⁵⁺ and Mo⁴⁺. XRD analysis confirmed the formation of Mo₄O₁₁ phase as an intermediate phase followed by MoO₂ phase. After 60 min of isothermal reduction, peaks of metallic molybdenum (Mo) appeared. Whereas, FESEM analysis showed porous crater-like structure on the surface cracks of MoO₂ layer which led to the growth of Mo phase. Meanwhile, the reduction of MoO₃ catalyst in 10% carbon monoxide (CO) showed the formation of unstable intermediate phase of Mo₉O₂₆ at the early stage of reduction. Furthermore, by increasing 20% CO led to the carburization of MoO₂ phase, resulted in the formation of Mo₂C rather than the formation of metallic Mo, as confirmed by XPS analysis. Therefore, the presented study shows that hydrogen gave better reducibility due to smaller molecular size, which contributed to high diffusion rate and achieved deeper penetration into the MoO₃ catalyst compared to carbon monoxide reductant. Hence, the reduction of MoO₃ in carbon monoxide atmosphere promoted the formation of Mo₂C which was in agreement with the thermodynamic assessment.     

An Empirical Study of Factors Affecting e-Commerce Adoption among Small- and Medium-Sized Enterprises in a Developing Country: Evidence from Malaysia

The purpose of this paper is to empirically examine determinants of e-commerce adoption among Malaysian small- and medium-sized enterprises (SMEs). This study tested eight hypotheses on determinants affecting e-commerce adoption with empirical data from several survey instruments: an online questionnaire-based survey, mailed survey and questionnaire collected in-person from a sample of 307 SMEs in Malaysia. The findings show that e-commerce adoption within Malaysian SMEs is affected by perceived relative advantage, perceived compatibility, managers/owner's knowledge and expertise, management characteristics and external change agents. This study contributes to enhancing the understanding of the determinants of adopting e-commerce in SMEs and provides some interesting perspective from Malaysia. Those parties interested in promoting their business online may find these results helpful in guiding their efforts.     

SCCN: A Time-Effective Hierarchical Interconnection Network for Network-On-Chip

Mobile Networks and Applications - The needed time to send and receive a message among two nodes in an interconnection network has a fundamental role in determining the performance of this network....     

Enrichment of Omega-3 Fatty Acids of Refined Hoki Oil

Enrichment of the omega-3 (n-3) fatty acids of refined hoki oil (RHO) intact triglycerides (TG) and via free fatty acids (FFA), was carried out in the present study using established methods of dry fractionation (DF), low temperature solvent crystallization (LTSC) and urea complexation (UC) and positional distribution of fatty acids in the intact TG was determined by Nuclear Magnetic Resonance (NMR) analysis. Results showed that n-3 fatty acids were enriched in liquid fractions of all methods except DF, where the highest concentration was obtained via the UC method (83.00 %). The FFA form of the oil produced a higher concentration (40.81 %) of n-3 fatty acids via the LTSC method compared to the TG form (31.50 %). The percentages of the total saturated fatty acid (SFA) in the liquid fractions in all methods were lower, ranging from 1.60 % (UC) to 21.44 % (DF) compared to the RHO parent oil (24.05 %). The percentages of total monounsaturated fatty acids (MUFA) in the liquid fractions were similar to the solid fractions except for the UC method where total MUFA was six times higher in the solid fraction. In LTSC-FFA and UC methods, the enrichment factor for EPA was lower, ranging from 1.61 (LTSC-FFA) to 2.83 (UC), than DHA which ranged from 1.64 (LTSC-FFA) to 3.88 (UC). EPA was preferentially located at the sn-1,3 position and DHA was significantly located at the sn-2 position which is the favoured location for intestinal digestion.     

Visual interface for searching and browsing children’s WebOPAC

This study focuses on the visual interface design of WebOPAC, which assists children in carrying out searching and browsing activities for bibliographical information in a library database. The existing interface of WebOPAC, called Ilmu, is investigated in this study; the interface is efficient in retrieving information from the database; however, its poor graphic design causes major usability problems. The graphic design of Ilmu is important in helping children to understand and visualise concepts of searching and browsing. Therefore, the interface must be constructed in such a way that can meet the needs of children aged 7–11 years. In this study, an analysis has been carried out on children’s requirements for the graphic design through participatory design activities using two approaches: cooperative inquiry and sketching of ideas. The cooperative Inquiry approach involved 40 children, while sketching children’s ideas involved 20 children as respondents. A total of 14 requirement specifications were generated and categorised into four areas—use of space, information organisation, function and use of colours; these would serve as a basis in designing a new WebOPAC interface. Synthesis of these requirements has shown that they are best supported through the implementation of visual interface display techniques. Chi-squared (χ ²) test was used to test the responses of children towards the usability of the new interface; the results showed a high level of acceptance by the children, recording a rate of 83.98 %.     

Recent developments in the organization goals conformance using ontology

Organizational goals serve as the most important achievement target in every organization. Even though some researchers have developed the concept of the organization goals, but structuring the organization goals model is always questionable by the way it is being used. In this paper, we propose ontology to develop a unified model for the organization goals structure. We review the recent literature on the organization modelling and ontology development as an effort to evaluate the organization goals using a metrics for the achievement of the organization goals. We suggest that the metrics is important to identify the relevant organization data in relation to the organization goals conformance. In order to achieve this purpose, we investigate various associated concepts and organize the literature based on the organization goals, organization ontology and metrics model. We observe our proposed models are important for domain experts and entrepreneurs to evaluate the relevant organization data and to assist them in decision making. In summary, the contribution of this survey may serve as a first step in understanding the evaluation of the organization data for the achievement of the organization goals.     

Potential of chitosan coating in delaying the postharvest anthracnose (Colletotrichum gloeosporioides Penz.) of Eksotika II papaya

The in vitro and in vivo fungicidal activity of chitosan was studied against Colletotrichum gloeosporioides, the causal agent of anthracnose in papaya fruits. Chitosan at 1.5% and 2.0% concentrations showed a fungistatic effect with 90–100% inhibition (significant at P ≤ 0.05) of the fungal mycelial growth. Changes in the conidial morphology were also observed with the higher chitosan concentrations after 7‐ h incubation. In vivo studies showed that 1.5% and 2.0% chitosan coatings on papaya not only controlled the fruit decay but also delayed the onset of disease symptoms by 3–4 weeks during 5 weeks storage at 12 ± 1 °C and slowed down the subsequent disease development. However, when leaving the fruits to ripen at ambient temperature (28 ± 2 °C), 2.0% chitosan was less effective than 1.5% in controlling the disease development. Chitosan coatings also delayed the ripening process by maintaining the firmness levels, soluble solids concentration and titratable acidity values during and after storage.     

Physical and chemical behaviour of tungsten oxide in the presence of nickel additive under hydrogen and carbon monoxide atmospheres

The physical and chemical behaviour of bulk tungsten oxide (WO₃) and Ni doped tungsten oxide (15% Ni/WO₃) were examined by performing a temperature-programmed reduction (TPR) technique. The chemical composition, morphology, and surface composition of both samples before and after reduced were analysed by X-ray diffraction (XRD), scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS) analysis. The XRD pattern of calcined Ni doped tungsten oxide powder comprised of WO₃ and nickel tungstate (NiWO₄) phases. The reduction behaviour was investigated by a non-isothermal reduction up to 900 °C achieved under (10 and 20% v/v) hydrogen in nitrogen (H₂ in N₂) and (20 and 40% v/v) carbon monoxide in nitrogen (CO in N₂) atmospheres. The H₂-TPR were indicated the reduction of bulk WO₃ and 15% NiWO₃ proceed in three steps (WO₃ → WO₂ → WO₂ + W) and (WO₃ → WO₂ → W + Ni₄W) respectively under 20% H₂. Whereas, the reduction of 15% WO₃ under 40% CO involves of two following stages: (i) low temperature (<800 °C) transformation of WO₃ → WO_2.72 → WO₂ and, (ii) high temperature (>800 °C) transformation of WO₂ → W → WC. Furthermore, NiWO₄ alloy phase was transformed according to the sequence NiWO₄ → Ni + WO_2.72 → Ni + WO₂ → Ni + W → Ni₄W + W at temperature >700 °C and >800 °C in H₂ and CO atmospheres, respectively. It can be concluded that the reduction behaviour of WO₃ is matched with the thermodynamic data. In addition, the reduction under H₂ is more favourable and have better reducibility compared to the CO gas. It is due to the small molecule size and molecule mass of H₂ that encourages the diffusion of H₂ molecule into the internal surface of the catalyst compared to CO. Moreover, Ni additive had improved the WO₃ reducibility and enhancing the CO adsorption and promotes the formation of tungsten carbide (WC) by carburisation reaction. Besides, the formation of Ni during the reduction of 15% Ni/WO₃ under CO reductant catalysed the Boudouard reaction to occur, which disproportionated the carbon monoxide to carbon dioxide and carbon (CO → CO₂ + C).     

Spectrofluorometric and Molecular Docking Studies on the Binding of Curcumenol and Curcumenone to Human Serum Albumin

Curcumenol and curcumenone are two major constituents of the plants of medicinally important genus of Curcuma, and often govern the pharmacological effect of these plant extracts. These two compounds, isolated from C. zedoaria rhizomes were studied for their binding to human serum albumin (HSA) using the fluorescence quench titration method. Molecular docking was also performed to get a more detailed insight into their interaction with HSA at the binding site. Additions of these sesquiterpenes to HSA produced significant fluorescence quenching and blue shifts in the emission spectra of HSA. Analysis of the fluorescence data pointed toward moderate binding affinity between the ligands and HSA, with curcumenone showing a relatively higher binding constant (2.46 × 10⁵ M⁻¹) in comparison to curcumenol (1.97 × 10⁴ M⁻¹). Cluster analyses revealed that site I is the preferred binding site for both molecules with a minimum binding energy of −6.77 kcal·mol⁻¹. However, binding of these two molecules to site II cannot be ruled out as the binding energies were found to be −5.72 and −5.74 kcal·mol⁻¹ for curcumenol and curcumenone, respectively. The interactions of both ligands with HSA involved hydrophobic interactions as well as hydrogen bonding.