Immobilized lipase from potential lipolytic microbes for catalyzing biodiesel production using palm oil as feedstock

Biodiesel has been regarded as a biodegradable and non-polluting fuel. Enzymatic transesterification reaction for manufacturing biodiesel from vegetable oils with alcohol is an attractive approach. However, the cost of enzyme remains a barrier for its industrial implementation. The aim of this research was the screening of lipase-producing microorganisms and the studies of potential lipase-mediated biodiesel production using palm oil as substrate. A total of 360 strains of bacteria, yeasts and fungi were isolated and screened from the samples of oil-contaminated soil and waste water. Among all the screened microbes, the potential lipolytic bacterium,  Staphylococcus warneri, unicellular yeast, Candida rugosa and filamentous fungus, Fusarium solani were selected because of their high specific  activities. The lipase-producing conditions were subsequently optimized by using palm oil as an inducer and lipase activities were compared for both hydrolytic and synthetic catalysis. C. rugosa lipase, which exhibited the highest potential for catalyzing the biodiesel production, was further  purified and immobilized on various hydrophobic supports. The catalysis of transesterification between methanol and palm oil by the C. rugosa immobilized lipases revealed that immobilized lipase from C. rugosa on Sepabeads EC-OD was the most promising for further development as a biocatalyst for the application of enzyme-catalyzed biodiesel synthesis.Key words: Screening, lipases, immobilization, biodiesel

Sol-gel synthesis and optical properties of malayaite ceramic colour pigments

Ceramic colour pigments based on the malayaite structure was synthesized by sol-gel with an aim to obtain homogeneous powder systems. The formulation was Ca(Sn1-xCrx)SiO5 where x = 0, 0.02 and 0.05. Thermogravimetric analysis and infrared spectroscopy suggested suitable calcination temperatures to be > 1000°C. Formation of malayaite phase was found to be very difficult; high calcination temperatures up to 1400°C was required which was typical for this particular phase. Nevertheless, small amounts of impurities were still present and were found to be both wollastonite (CaSiO3) and cassiterite (SnO2). The oxidation state of chromium was found to be mainly 4+. The obtained pigment particles were in the range of 1-5 micron with a high degree of agglomeration due to sintering. UV-vis spectra demonstrated broad absorbance peak in the 550-600 nm range which could be attributed to both Cr(III) and Cr(IV). The colour parameters in the CIELab system showed a red tone (more positive a* values whereas b* remained relatively constant) when chromium was doped into the malayaite host. Preliminary interaction testing with a low-fire glaze displayed an even improvement in the a* parameter (getting more red tone). Microscopic studies showed a certain degree of chromium diffusion out of the pigment powders toward the glaze matrix. These results have demonstrated a great potential for this refractory colour pigments to be possibly utilized in other kinds of glazes as well

The Potential of Cellulosic Ethanol Production from Grasses in Thailand

The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85–38.51, 31.13–42.61, and 3.10–5.64, respectively. The samples were initially pretreated with alkaline peroxide followed by enzymatic hydrolysis to investigate the enzymatic saccharification. The total reducing sugars in most grasses ranging from 500–600 mg/g grasses (70–80% yield) were obtained. Subsequently, 11 types of grasses were selected as feedstocks for the ethanol production by simultaneous saccharification and cofermentation (SSCF). The enzymes, cellulase and xylanase, were utilized for hydrolysis and the yeasts, Saccharomyces cerevisiae and Pichia stipitis, were applied for cofermentation at 35°C for 7 days. From the results, the highest yield of ethanol, 1.14 g/L or 0.14 g/g substrate equivalent to 32.72% of the theoretical values was obtained from Sri Lanka ecotype vetiver grass. When the yields of dry matter were included in the calculations, Sri Lanka ecotype vetiver grass gave the yield of ethanol at 1,091.84 L/ha/year, whereas the leaves of dwarf napier grass showed the maximum yield of 2,720.55 L/ha/year (0.98 g/L or 0.12 g/g substrate equivalent to 30.60% of the theoretical values)

Procuring sustainably in social housing: The role of social capital

In order to explore its many complexities, scholars have called for a move beyond, descriptions of sustainable procurement. This study responds by seeking insights into sustainable procurement through the lens of social capital theory. Social capital is conceptualized as comprising cognitive, social and relational elements. Sustainable procurement is seen as a means of pursuing environmental, economic and social goals through the purchasing and supply process. The study, proposes and empirically tests the operational measures of social capital and their relationship with, sustainable procurement activity on a sample of 135 procurement professionals in organizations, providing social housing. The results indicate partial support for the study proposition; structural, social capital, rather than structural, social and relational taken together, is found to be the most robust predictor of sustainable procurement. The results highlight the importance of broadening, collaboration models for sustainable procurement beyond an exclusive focus on dyadic relations. It, also demonstrates that this broader engagement with other stakeholders focused on knowledge creation, as well as knowledge sharing, is a significant contributor to sustainable procurement activity. © 2014 Elsevier Ltd

Advancing the sustainable development goals: evidence from leading European banks

The Sustainable Development Goals (SDGs) reflect grand challenges the global community needs to address in order to ensure economic welfare, environmental quality as well as social cohesion and prosperity for future generations. In this respect, the role of the banking sector, among other critical business entities and key stakeholders, is vital. The purpose of our paper is to examine how comprehensively the reported performance of banks aligns with the endorsement of the SDGs. We employ the well-established framework of the Global Reporting Initiative (GRI) performance indicators for a comparative assessment of the nonfinancial performance disclosed in the annual sustainability reports. Focusing on a small sample of leading European banks, we find an overall low contribution to the SDGs. Furthermore, each bank’s contribution remains particularly heterogeneous towards most individual SDG goals. Likewise, bank-specific strategies drive the most extensively addressed SDGs, overlooking any critical importance of certain GRI indicators with multifaceted impact across several SDGs. The study sets forth managerial implications for improving effective reporting of SDG performance. It concludes with emerging opportunities for enhancing disclosure of SDGs contribution and highlights future research perspectives towards industry-wide shared-value appraisal under the scope of these pressing grand challenges

Measuring the Environmental Sustainability Performance of Global Supply Chains: a Multi-Regional Input-Output analysis for Carbon, Sulphur Oxide and Water Footprints

Measuring the performance of what an environmentally sustainable supply chain has become a challenge despite the convergence of the underlining principles of sustainable supply chain management. This challenge is exacerbated by the fact that supply chains are inherently dynamic and complex and also because multiple measures can be used to characterize performances. By identifying some of the critical issues in the literature regarding performance measurements, this paper contributes to the existing body of literature by adopting an environmental performance measurement approach for economic sectors (primary, secondary and tertiary sectors). It uses economic sectors and evaluates them on a sectoral level in specific countries as well as part of the Global Value Chain based on the established multi-regional input-output (MRIO) modelling framework. The MRIO model has been used to calculate direct and indirect (that is supply chain or upstream) environmental effects such as CO2, SO2, biodiversity, water consumption and pollution to name just a few of the applications. In this paper we use MRIO to calculate emissions and resource consumption intensities and footprints, direct and indirect impacts, and net emission flows between countries. These are exemplified by using carbon emissions, sulphur oxide emissions and water use in two highly polluting industries; Electricity production and Chemical industry in 33 countries, including the EU-27, Brazil, India and China, the USA, Canada and Japan from 1995 to 2009. Some of the results highlights include: On average, direct carbon emissions in the electricity sector across all 27 member states of the EU was estimated to be 1368 million tonnes and indirect carbon emissions to be 470.7 million tonnes per year representing 25.6% of the EU-27 total carbon emissions related to this sector. It was also observed that from 2004, sulphur oxide emissions intensities in electricity production in India and China have remained relatively constant at about 62.8 gSOx/$and 84.4 gSOx/$ although being higher than in other countries. In terms of water use, the high water use intensity in China (1040.27 litres/$) and India (961.63 litres/$), which are among the highest in the sector in the electricity sector is exacerbated by both countries being ranked as High Water Stress Risk countries. The paper also highlights many merits of the MRIO including: a 15-year time series study (which provides a measurement of environmental performance of key industries and an opportunity to assess technical and technological change during the investigated time period), a supply chain approach that provides a consistent methodological framework and accounts for all upstream supply chain environmental impacts throughout entire global supply chains. The paper also discusses the implications of the study to environmental sustainability performance measurement in terms of the level of analysis from a value chain hierarchy perspective, methodological issues, performance indicators, environmental exchanges and policy relevance

Optimization of microwave response in barium nickel and zinc tantalate perovskites

Complex perovskites, such as BaZn1/3Ta2/3O 3 (BZT), are currently used in mobile phone base stations. To increase the system efficiency, these materials are required to possess low dielectric losses or high quality factors (Q). Q\u27s have been reported to be associated with the degree of cation order, which can be induced through extended high-temperature processing. ZnO volatilization often complicates the resultant crystal chemistry and the relationship of the structure to Q. BaNi1/3Ta2/3O3 (BNT) and Ni-doped BaZn 1/3Ta2/3O3 (BNZT) were employed in this study. The ordering kinetics in BNT powders and pellets was studied by annealing treatments at various temperatures and times. The effect of non-stoichiometry and processing atmosphere on the ordering, sintering and dielectric properties was investigated. This study resulted in a better understanding of correlations among different order variables. The lattice distortion (c/a) has been shown to be more influenced by the ordered domain size (D) than by the degree of order (S). The domain growth was also found to be anisotropic; the domain size along [100] or D 100 is always larger than that along [001] (D 001). In addition, the uncovering of an ordered domain size gradient in dense pellets provides an explanation to the inferior Q values commonly encountered in large, commercial pucks. Different types of non-stoichiometry and processing atmosphere were demonstrated to influence the order stability, sinterability and microwave response. Large improvement in as-sintered Q (∼ 10,000 to ∼ 12,000) was observed in the samples located along BNZT-(Ni0.13Zn0.87)Ta 2O6, BNZT-BaTa2O6, BNZT-Ta2O 5 and BNZT-Ba8(Ni0.13Zn0.87)Ta 6O24 pseudo-binaries. The highest Q ∼ 14,000 was obtained in a BNZT-Ba8(Ni0.13Zn0.87 )Ta6O24 sample sintered at 1500°C for 24 hours. These high-Q, fully-ordered samples were always accompanied by large lattice distortion and extensive domain growth. In addition, sintering temperatures could be lowered by ∼ 75°C (to 1375°C, 12 hours for BaO-deficient BNZT) when processing in a ZnO vapor-rich atmosphere, and its resultant Q could be further improved up to ∼ 12,000 by post-sintering annealing at 1350°C. These findings enable further improvement in the microwave response in the existing dielectric perovskite materials. A large reduction in the annealing time to reach a high-Q state can be achieved through controlled manipulations of the stoichiometry. The lowering in the sintering temperature and time, by alterations in the sintering atmosphere, minimizes complications of ZnO volatilization commonly encountered in BZT-based ceramics

Optimization of microwave response in barium nickel and zinc tantalate perovskites

Complex perovskites, such as BaZn1/3Ta2/3O 3 (BZT), are currently used in mobile phone base stations. To increase the system efficiency, these materials are required to possess low dielectric losses or high quality factors (Q). Q\u27s have been reported to be associated with the degree of cation order, which can be induced through extended high-temperature processing. ZnO volatilization often complicates the resultant crystal chemistry and the relationship of the structure to Q. BaNi1/3Ta2/3O3 (BNT) and Ni-doped BaZn 1/3Ta2/3O3 (BNZT) were employed in this study. The ordering kinetics in BNT powders and pellets was studied by annealing treatments at various temperatures and times. The effect of non-stoichiometry and processing atmosphere on the ordering, sintering and dielectric properties was investigated. This study resulted in a better understanding of correlations among different order variables. The lattice distortion (c/a) has been shown to be more influenced by the ordered domain size (D) than by the degree of order (S). The domain growth was also found to be anisotropic; the domain size along [100] or D 100 is always larger than that along [001] (D 001). In addition, the uncovering of an ordered domain size gradient in dense pellets provides an explanation to the inferior Q values commonly encountered in large, commercial pucks. Different types of non-stoichiometry and processing atmosphere were demonstrated to influence the order stability, sinterability and microwave response. Large improvement in as-sintered Q (∼ 10,000 to ∼ 12,000) was observed in the samples located along BNZT-(Ni0.13Zn0.87)Ta 2O6, BNZT-BaTa2O6, BNZT-Ta2O 5 and BNZT-Ba8(Ni0.13Zn0.87)Ta 6O24 pseudo-binaries. The highest Q ∼ 14,000 was obtained in a BNZT-Ba8(Ni0.13Zn0.87 )Ta6O24 sample sintered at 1500°C for 24 hours. These high-Q, fully-ordered samples were always accompanied by large lattice distortion and extensive domain growth. In addition, sintering temperatures could be lowered by ∼ 75°C (to 1375°C, 12 hours for BaO-deficient BNZT) when processing in a ZnO vapor-rich atmosphere, and its resultant Q could be further improved up to ∼ 12,000 by post-sintering annealing at 1350°C. These findings enable further improvement in the microwave response in the existing dielectric perovskite materials. A large reduction in the annealing time to reach a high-Q state can be achieved through controlled manipulations of the stoichiometry. The lowering in the sintering temperature and time, by alterations in the sintering atmosphere, minimizes complications of ZnO volatilization commonly encountered in BZT-based ceramics

Review of intellectual capital research on measuring and reporting

"October 2004"Cover title.Online copy: 1445-3037.Bibliography: p. 16-20.Also available online at http://www.mgsm.edu.auiii, 31 leave

Intellectual capital reporting: comparison of various frameworks

"October 2004"Cover title.Online copy: 1445-3037.Bibliography: p. 16-20.Also available online at http://www.mgsm.edu.auiii, 19 leave