The influence of carbonization temperature on the development of carbon membrane with superior CO2/CH4 separation performance Pengaruh suhu karbonisasi kepada pembangunan membran karbon dengan kesan pemisahan gas CO2/CH4 yang cemerlang

In this study, P84-based carbon tubular membranes were fabricated and characterized in terms of their structural morphology and gas permeation properties, by using Scanning Electron Microscopy (SEM) and pure gas permeation system, respectively. The polymer tubular membranes were then carbonized under nitrogen atmosphere at different carbonization temperatures of 600, 700, 800 and 900 °C, with heating rate of 3°C/min and thermal soak time of 30 minutes. The manipulation of carbonization temperatures was required to see if it could enhance the permeation properties as desired. Pure gas permeation tests were performed using CO2 and CH4 gases. The CO2/CH4 selectivity was found increasing as the carbonization temperature was increased from 600 to 800 °C. The carbon membrane carbonized at 800°C showed the most promising result for CO2/CH4 selectivity, rendering 69.48 and CO2 permeance of 206.1 GPU

Performance of sustainable alkali activated mortars containing solid waste ceramic powder

As the cement industry contributed to increasing the global carbon dioxide emissions, researchers looked for other sustainable alternatives. Among them, one of the alternatives is alkali activated mortar containing no cement at all. Alkali-activated mortar is manufactured using industrial and agricultural wastes like ceramics, palm-oil fuel ash (POFA), granulated blast furnace slag (GBFS), fly ash (FA), metakaolin (MK), etc. Compared with Ordinary Portland Cement (OPC), alkali-activated is considered as a highly environmental product based mortar. The alkali activated mortar feasibility production using ceramic waste binder was evaluated in this study. The effect of replacing GBFS binder by ceramic powder (by varying percentage) upon its fresh-state properties, like workability, setting time, density and hardened properties such as compressive, tensile and flexural strengths of alkali-activated mortar was concurrently examined. The impact of curing regime on strength development of ceramic-GBFS based alkali activated was evaluated as well. Results revealed that with increased ceramic to GBFS content, the workability and setting time of mortar improved whereas the density decreased. On the other hand, when ceramic was replaced by up to 50 % of GBFS, it showed higher strengths as compared to OPC mortar. It is concluded that alkali activated mortar incorporating 100 percent wastes could be used in the construction industry with the almost negligible amount of environmental problems

Effect of binder to fine aggregate content on performance of sustainable alkali activated mortars incorporating solid waste materials

This article investigated the effects of binder to aggregate ratio on the properties of granulated blast furnace slag (GBFS) alkali activated mortar incorporated with fly ash (FA), waste ceramic (CP) and bottle glass wastes (GP). Five types of alkali-activated mortars were prepared with a different binder to fine aggregate ratio (B:A) 0.30, 1.0, 1.5, 2.0 and 2.5. Sodium hydroxide (NH) with 6 molar concentrations added to sodium silicate (NS) and used as alkali activator solution, alkaline liquid to binder ratio (S:B) was kept 0.25 for all mixtures. Alkali-activated samples cured at ambient temperature (27 °C) and relative humidity (75 %). The results indicated that 1.0 (B:A) ratio was achieved the optimum results flow and bending stress, increasing binder to fine aggregate content effect negatively on workability and strength properties of alkali-activated mortars. The results also presented the porosity of alkali-activated samples has been influenced by increase binder content to fine aggregate from 1.0 to 2.5

Performance comparison of PI and PI-fuzzy controller for grid-connected fuel cell inverter system

This paper presents the modeling, simulation, and performance evaluation of a hybrid proton exchange membrane fuel cell (PEMFC) with an energy storage system utilized in a grid-connected distributed generation (DG) system. To control the fuel cell/battery grid-side voltage source inverter (VSI), the conventional voltage-mode and currentmode control schemes with improved proportional-integral (PI)-fuzzy controller for both inner current and outer voltage control loops have been developed. The proposed PI-fuzzy controller has the advantage of fuzzy control while maintaining the simplicity and robustness of the PI controller. The space-vector pulse width modulation technique has been applied to the VSI control to generate a sinusoidal waveform. A comparison has been made between the PI-fuzzy controller and the PI controller in the VSI in terms of the generated total harmonic distortion (THD). The results showed that by applying PI-Fuzzy controller, the voltage and current THD are reduced to 0.40 % and 3.77 %, respectively compared to 0.43 % voltage THD and 14.08 % current THD using the conventional PI controller

A comparative study to determine the shock absorption ability of two popular mouth guards available on the South African market

It is expected that most mouth guards will provide some level of protection to teeth. In this study a device was developed to measure the relative impact absorption of two different mouth guards (Proform, Type III vacuum-formed and Max, Type IV pressure laminate). Seven of each of the two types of mouth guards were made and each batch was exposed to between six and 10 impact trials.DHE

Impact of foreign aid and foreign direct investment on economic growth: evidence from Sub-Saharan African countries

The purpose of this study is to examine the impact of foreign aid and FDI on economic growth of Sub-Saharan African countries. The generalized method of moments is applied on 41 countries covering the period of 1998 to 2010. The results suggest that while foreign aid has negative effect on growth, the impact of FDI is positive but statistically insignificant. Furthermore, we found evidence that foreign aid from different bilateral donors may have different effects on economic growth

Designing an Arabic Handwritten Segmentation System

The greatest difficulty facing the recognition of Arabic handwritten words is segmentation, because Arabic handwriting is cursive with complex multi-form styles. Hence, intensive research efforts are needed to reach an effective Arabic handwriting segmentation system. This paper presents a system which uses morphological features of the Arabic characters for segmentation. The proposed system segments non-overlapped (horizontally connected -e.g. "حسن") as well as overlapped (vertically connected - e.g. "نجد") characters. The result is not very good one. However, it arrives at good directives for more research. As the writing was freely without any restrictions, both over-segmentation and under-segmentation problems affect the system.

Effect of Psychological Empowerment and Transformational Leadership on Organizational Commitment

According to recent literature that relates to organizational leadership, transformational leadership consists of three important elements: idealized influence, individual consideration and intellectual stimulation. Extant studies in this area highlighted that the ability of the leaders in implementing these transformational processes (to execute organizational functions) may have a significant impact on individual outcome especially organizational commitment. Although this relationship has been studied, the mediating role of transformational leadership has taken a less prominent role in organizational leadership model. Recent studies on organizational leadership have emphasized that transformational leadership has three important characteristics: idealized influence, individual consideration and intellectual stimulation. The purpose of this paper is to examine the influence of empowerment in the relationship between transformational leadership and organizational commitment; by using 77 USAble questionnaires gathered from employees who worked at a foreign manufacturing company in Free Trade Zone, Malaysia. Results of SmartPLS path model analysis confirm that empowerment does act as an important mediating variable in the relationship between transformational leadership and organizational commitment in the organizational sample. In the succeeding sections, discussion, implications and conclusion are elaborated

Supplier-contractor partnering impact on construction performance: A study on Malaysian construction industry

The construction sector plays an important role in the national economy through strengthening and enabling other sectors.Construction provides basic amenities and infrastructures that support social development.Despite its important contribution, the industry is still saddled with serious problems such as poor quality, low productivity, poor image, economic volatility, bureaucratic delays, and cost overruns.With an eye to overcoming these problems, this paper proposed a study on supplier-contractor partnering and its impact on construction performance

Porous amphiphilic biogel from facile chemo-biosynthetic route

Grafting of medium-chain-length poly-3-hydroxyalkanoates (mcl- -PHA) with glycerol 1,3-diglycerolate diacrylate (GDD) in acetone was performed using benzoyl peroxide as the initiator. A detailed mechanism scheme provides significant improvement to previous literature. Radical-mediated grafting generated –carbon inter-linking of mcl-PHA and GDD, resulting in a macromolecular structure with gel properties. The thermal properties of the copolymer for different graft yields were investigated as a function of initiator concentration, GDD monomer concentration, incubation period and temperature. The water absorption and porosity of the gel were significantly improved relative to neat mcl-PHA