3D scaffolds coated with nanofibers displaying bactericidal activity for bone tissue applications

Bone-limited capacity to fully repair large defects requires the development of new implants. In this context, new approaches have been used to promote bone regeneration and also to avoid the side effects associated with the therapeutics currently used in the clinic. Herein, 3D tricalcium phosphate/alginic acid scaffolds were produced and then coated with an electrospun mesh loaded with two different antibacterial agents, silver nanoparticles, and salicylic acid. The obtained results showed that the produced scaffolds have suitable mechanical properties, swelling, biodegradation, biomineralization activity, enhanced cellular adhesion/proliferation and bactericidal activity, and features essential for bone regeneration.     

Overall Energy Requisite and Quality Feature of Industrial Paddy Drying

Energy consumption and rice quality are the main concerns of millers and must be assessed to ascertain suitable industrial drying strategy. In this article, industrial paddy drying methods as usually practiced in the BERNAS paddy drying complexes of Malaysia have been evaluated. The analysis showed that the specific electrical and thermal energy consumption varied between 16.19 kWh to 22.07 kWh and 787.22 MJ to 1015.32 MJ, respectively, in single-stage paddy drying (SSPD) using an inclined bed dryer (IBD) to dry each tonne of freshly harvested paddy with average moisture content of 23.35 ± 0.86% wb. On the other hand, the energy consumptions for two-stage paddy drying (TSPD) with a fluidized bed dryer (FBD) followed by IBD were 21.37 kWh/t to 30.69 kWh/t and 666.81 MJ/t to 1083.42 MJ/t, respectively. SSPD at 35–39°C and TSPD using FBD at 120°C as the first stage, followed by IBD as the second stage at lower temperature of 35–39°C yielded 2–3.6% higher head rice yield than paddy-dried by a single stage with IBD using comparatively higher temperature of 40–44°C. Therefore, IBD is recommended to be operated using a temperature of 35–39°C both in single-stage drying and second-stage drying of paddy after fluidized bed drying to obtain quality rice.     

Toward software quality enhancement by Customer Knowledge Management in software companies

Customer Knowledge Management (CKM) plays an important role in the production of high quality software products. As CKM in Enterprise Software (ES) development is still immature, this raises questions on how CKM enablers can be used to help ES development companies improve their software quality. In this study, Human, Organizational and Technological CKM enablers were identified from the literature. The weights of these factors were determined by experts from the ES development companies. Based on the most important factors, a theoretical model was developed. The proposed model was evaluated by distributing a survey questionnaire to decision-makers in ES development companies. The results showed that “Customer Involvement” together with “Trust” were the most influential factors, followed by “CRM Technology Infrastructure” and “Cross-Functional Cooperation”. In addition, there was no impact from “Organizational Training”, “Customer Knowledge Map”, and “CKM Strategy Development”. The results also revealed that the impact of CKM on software quality is significant. The proposed model in this study can be used as a guideline for the successful application of CKM in ES development companies to improve the software quality.     

Scalable and efficient key management for Mobile WiMAX networks

Efficiency and security are two critical but often conflicting issues in Multicast and Broadcast Service of IEEE 802.16e technology. Hence, it is vital to ensure an optimal scenario where neither security concerns, nor operational efficiency of the network is compromised. This paper proposes a new key management scheme called Scalable and Efficient Key Management Protocol, which uses a binary tree structure together with a B‐tree of order 2 structure. It focuses on improving key management performance of the existing techniques in terms of efficiency and scalability, without a loss in security. Scalable and Efficient Key Management Protocol dynamically establishes subgroups based on the current number of Mobile Stations in a WiMAX Base Station's coverage area. This will optimize the communications, computational and storage costs of the network. In addition, the scheme guarantees strong network scalability. Both analytical and simulation approaches have been carried out, and the results showed that the proposed scheme exhibits superior performance in terms of efficiency and scalability compared with existing schemes. Copyright © 2012 John Wiley & Sons, Ltd.     

Tocopherols of oil palm leaf1

Tocopherols of oil palm leaves were determined by high perfor-mance liquid chomatography. Each tocopherol was identified by a combination of gas chromatography-mass spectrometry and thin layer chromatography. The extracts of the leaves contained α- tocopherol (11,229-14,805 μg/g) and β-tocopherol (30-44 μg/g). Tocopherol composition and content of the leaves was compared to those of oil palm fruits. Presented at the JOCS meeting, Tokyo, November 1982.     

Relationship between the identity formation process and career development.

Proposed on the basis of a review of the ego identity and career development literatures that variability in career exploration and occupational commitment might be related to characteristic differences in the manner by which individuals explore and commit to their ego identity in late adolescence. To test propositions about the relations between career development and identity formation, measures of ego identity status, exploratory activity, and occupational commitment were administered to 99 college students. A canonical analysis was conducted, which yielded two significant canonical roots. The 1st root, which accounted for 35% of the variance between canonical composites, indicated that occupational commitment is inversely related to the moratorium status. The 2nd root, which accounted for 11% of the variance, suggested that career exploration is positively associated with the moratorium and identity-achieved statuses and inversely related to the diffusion status. The results are related to future directions in theory, research, and practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of an edge crack in a semi-infinite composite with a long reinforced phase

For the purpose of clarifying the micro fracture of continuous fiber unidirectionally reinforced composite materials, the problem of an edge crack perpendicular to a long reinforced phase is considered on the basis of the plane strain theory of elasticity. The stress intensity factor at the tip of the crack, and the stresses on the interface between the matrix and the reinforced phase and in the reinforced phase are discussed. In the analysis, the method of continuous distributions of dislocations is used. Then, a singular integral equation is derived and is solved by the technique developed by Erdogan and Gupta. From the numerical results it was concluded that:

1. The stress intensity factor decreases monotonically as the crack tip approaches the reinforced phase. That is, the presence of the reinforced phase can result in crack arrest.
2. When the crack tip exists near the reinforced phase, the normal stress on the interface between the matrix and the reinforced phase has a maximum at the intersection of the extension of the edge crack and the reinforced phase, while the shear stress on the interface and the normal stress in the reinforced phase take, respectively, maxima at symmetric points with respect to the crack surface in the immediate vicinity of the intersection.
3. The maximum values of the stresses on the interface and in the reinforced phase increase monotonically as the crack tip approaches the reinforced phase.

     

Flow and sediment yield simulations for Bukit Merah Reservoir catchment, Malaysia: a case study

Bukit Merah Reservoir is the main potable and irrigation water source for Kerian District, Perak State, Malaysia. For the past two decades, the reservoir has experienced water stress. Land-use activities have been identified as the contributor of the sedimentation. The Soil and Water Assessment Tool (SWAT) was used to simulate and quantify the impacts of land-use change in the reservoir watershed. The SWAT was calibrated and two scenarios were constructed representing projected land use in the year 2015 and hypothetical land use to represent extensive land-use change in the catchment area. The simulation results based on 17 years of rainfall records indicate that average water quantity will not be significantly affected but the ground water storage will decrease and suspended sediment will increase. Ground water decrease and sediment yield increase will exacerbate the Bukit Merah Reservoir operation problem.     

Spatial optimization of photovoltaic-based hydrogen-electricity supply chain through an integrated geographical information system and mathematical modeling approach

Clean Technologies and Environmental Policy - Hydrogen is a potential energy carrier for renewable energy as it has a clean emission when consumed. To implement hydrogen energy system in...     

A Novel Energy Efficient Key Distribution Scheme for Mobile WiMAX Networks

Wireless Personal Communications - In Mobile WiMAX, a Base Station (BS) delivers security keys to Mobile Stations (MSs) through a key distribution scheme to guarantee security and access control....