A further step toward H2 in automobile : development of an efficient bi-functional catalyst for single stage water gas shift

The suitability of polymer electrolyte fuel (PEM) cells for stationary and vehicular\ud applications initiated research in all areas of fuel processor (i.e. reformer, water-gas-shift,\ud preferential oxidation of CO (PROX)) catalysts for hydrogen generation. Water gas shift\ud (WGS) reaction is an essential part of these processors because of its role in CO\ud purification, which poisons the Pt electrodes of PEM, and its role in generating additional\ud hydrogen. The WGS reaction is well established in conventional large steady-state\ud operations, such as ammonia plants, but it has found new purpose and challenges to fit\ud the requirements for energy power generation through fuel cell. More active catalysts are\ud necessary as large volumes of shift reactors are usually required which would be\ud responsible for about 50% of the volume of the whole fuel processor. Therefore,\ud replacing the conventionally two stages WGS, i.e. the high temperature shift and the low\ud temperature shift, with a single stage WGS shift seems to be promising for reducing the\ud total volume of fuel processor. In this dissertation, a development of active, selective,\ud and stable single stage water-gas-shift (WGS) catalyst for H2 production for fuel cell\ud applications has been investigated. Such efficient catalysts could be used in a H2 selective\ud catalytic membrane reactor in order to overcome thermodynamic limitations when\ud temperature is chosen relatively high for improving reaction rate

Purification, Characterization and Molecular Studies of Fructose-6-Phosphate Phosphoketolase (F6PPK) from Bifidobacteria

Fructose-6-phosphate phosphoketolase (F6PPK; EC 4.1.2.22) is the key enzyme in the fructose-6-phosphate shunt pathway of glucose metabolism which is apparently restricted to bifidobacteria. Despite the biological importance of this bacterial group and the heterogeneity of the enzyme from different species, F6PPK in itself has not been characterized in detail with respect to size, subunit number, steady kinetics and N-terminal sequence. F6PPK was extracted and characterized for the first time from Bifidobacterium asteroides (isolated from the intestine of honeybees; ATTC 25909). The enzyme was purified to homogeneity using acetone fractionation at 40-70% saturation followed by fast protein liquid chromatography (FPLC) on Mono-Q anion exchange and Superose 12 gel filtration columns. The intact enzyme has a relative molecular mass of 110 ± 5 kDa as estimated by gel filtration chromatography (Sephadex G-200), and a single band was obtained on nondenaturingP AGE. It was then shown to be that of F6PPK following elution from preparative polyacrylamid gel. Sodium dodecyl sulphate (SDS)-PAGE under nonreducing conditions revealed the presence of a single polypeptide of 110 ± 2 kDa. SDS-PAGE of F6PPK reacted with 2-mecaptoethanol revealed the presence of two polypeptides of 59 ± 1 and 53 ± 0.5 kDa, indicating a dimeric structure (α₁ β₁) with disulfide-linked subunits. The NH2-terminal amino acid of the a. chain was found to be methionine. The enzyme was stable at pH 4.5-8.0 with an optimum activity at pH 6.0. The enzyme was stable below 42°C and the optimum temperature was 30°C. The apparent Km value of the enzyme for fructose-6-phosphate was 14.1 mM. The purified enzyme has no apparent requirement for thiamine pyrophosphate as cofactors. The enzyme was inactivated by Hg2+ and recovered after addition of dithiothretol, indicating that sulfhydryl group was probably involved in the enzyme activity. The features of B. asteroides F6PPK showed marked differences from those previously reported from animal and human strains. F6PPK from Bifidobacterium longum (probiotic grade; BB536) was also purified to electrophoretic homogeneity using the same purification steps above. The purified enzyme had a molecular mass of about 300 kDa as determined by gel filtration on Superose 12. F6PPK migrated as a single electrophoretic band in nondenaturing polyacrylamide gel electrophoresis (PAGE). It is probably a tetramer containing two different subunits with molecular masses of about 93 ± 1 kDa and 59 ± 0.5 kDa, as determined by SDS-PAGE. The N-terminal amino acid sequences of the subunits were determined, and no significant similarity was found between the deduced amino acid sequences and those in the databases of EMBL and SWISSPORT, indicating that we may be reporting for the first time the partial sequence of F6PPK from two type strains of Bifidobacterium species. However, the Mr 59000 subunit of B. asteroides F6PPK showed a significant similarity (70%) with the corresponding subunit from B. longum species. Oligonucleotide probes which were designed based on the deduced N-terminal amino acids sequences were unable to detect the presence of F6PPK gene using dot blot and Southern blot of the total genomic DNA from different species of bifidobacteria and other bacterial strains. In addition, the genomic library of B. asteroides was constructed in BamHI-digested pUCI9 by using about 2 to 6-kb DNA fragments obtained by partial digestion of the total genomic DNA with BamHI. The transformed cells efficiency of E. coli XLI- blue carrying plasmids with genomic inserts was 1.1 x 104 cfu mrl, and this library may be a useful tool for fishing the gene encoding for F6PPK

Kesan pelaburan langsung asing terhadap pertumbuhan ekonomi: perbandingan antara negara berpendapatan tinggi dengan sederhana menggunakan pendekatan kointegrasi asimetri

Walaupun peranan pelaburan langsung asing (FDI) terhadap pertumbuhan ekonomi telah banyak dibahaskan, namun begitu penyelidikan perbandingan antara negara berpendapatan tinggi dengan sederhana berdasarkan pendekatan kointegrasi asimetri adalah terhad. Oleh itu, kertas ini mengkaji kesan pelaburan langsung asing terhadap pertumbuhan ekonomi dengan membandingkan antara negara berpendapatan tinggi dengan sederhana menggunakan data siri masa dari tahun 1970 sehingga 2014. Kertas kerja ini menggunakan prosedur Johansen (1988) untuk kointegrasi simetri, manakala ujian kointegrasi ambang yang dicadangkan oleh Enders dan Siklos (2001) digunakan untuk kointegrasi asimetri. Hasil kajian mendapati keputusan asimetri menunjukkan negara-negara maju seperti Jepun dan Korea mempunyai pekali penyelarasan jangka panjang yang bersifat asimetri dan sisihan negatif bertindak lebih cepat apabila terdapat sisihan jangka panjang. Berbeza pula dapatan dengan negara sedang membangun seperti Malaysia dan Indonesia di mana pelarasan keseimbangan jangka panjang adalah bersifat simetri. Hal ini menunjukkan bahawa pekali pelarasan adalah sama tidak kira jika kesilapan keseimbangan positif atau negatif. Secara keseluruhan, keputusan kajian menunjukkan semua negara mempunyai hubungan jangka panjang antara FDI dan pertumbuhan ekonomi. Oleh itu, keputusan ini penting bagi penggubal dasar untuk memahami hubungan antara pelaburan langsung asing dengan pertumbuhan ekonomi, terutamanya berkaitan dengan kesan asimetri. Pembuat dasar perlu mengambil perhatian dengan sebarang kejutan yang akan berlaku kepada ekonomi

Treatment of Emulsified Oil in Produced Water from Oil wells by Adsorption on to Corn-Cob as Sorbent

In this work , a fixed –bed system has been used to study the performance of corn-cob as low cost adsorbent for Treatment of dispersed oil droplets in oil-well product water in this system . In effect of initial oil content (600-1500 ppm), volumetric flow rate (2-5L/min), Bed height (25-35cm) and particle size (1.05-1.6mm) were studied. The results show that removal oil efficiency reaches high percent with decreasing of initial oil concentration, volumetric flow rate particle size and increasing of bed height

Evaluation of 2008 Traffic Safety Policies in Jordan

The problem of traffic accidents is a major problem in the Hashemite Kingdom of Jordan and represents a serious safety and economic challenge for the state. Traffic accidents are considered the second leading cause of death. This paper evaluated the impacts of the traffic policies undertaken in 2008 on traffic accidents and fatalities, including the intensification of police enforcement and implementation of traffic law with stiff penalty levels. To accomplish this objective, accidents’ data of 1990 through 2009 were obtained from Jordan Traffic Institute and other related sources. Results of analysis revealed that Jordan has experienced huge human and economic losses as well as social and emotional negative impacts. Furthermore, the safety policy measures undertaken in 2008, including the intensification of police enforcement and the increase of penalties for excessive speed had an overall positive influence in reducing accidents and fatalities. However, the application of 2007 traffic policy with stiffer penalties was the most effective measure. Finally, it is highly recommended to reapply 2007 traffic law with stiffer penalties since it contributed in reducing accidents and fatalities more than 2008 traffic law. In addition, it is recommended to apply all the needed safety polices to reduce the traffic accidents phenomenon in Jordan

Protein profiling during mesocarp development in oil palm fruit

This study was aimed at investigating the overall protein profiles of oil palm fruit during the mesocarp tissue development by means of isoelectric focusing (IEF) and two-dimensional gel electrophoresis (2-DE). Total protein was extracted from different stages of fruit development (namely, 5, 12, 15, 17, and 20 weeks after anthesis [WAA]) from Elaeis guineensis Jacq. Teñera and E. oleifera (17 WAA). The IEF separation was carried out on pH values ranging from 4.0-8.0. Changes in the patterns of protein after IEF were observed during mesocarp development and between the two species. The analysis of oil palm mesocarp gave rise to a protein map, comprising approximately 150 spots that were detectable by silver staining following high resolution 2-DE, with a pH range of 4.5-8.0 and a mass range of 8-100 kDa. Meanwhile, twenty five spots of protein showing variations in their intensity during the development of the mesocarp, with their pI ranging from 4.5-7.8 and Mr 20-85 kDa, were analyzed. Continuous but non-uniform disappearance of some proteins and formation of new proteins were observed at the early stages of mesocarp development and during certain periods of oil synthesis and fruit ripening. The results of this study indicate that developing mesocarp revealed significant changes in the protein profiles during fruit development. However, further studies are still required to identify the proteins that are differentially expressed during fruit development

A Self-Learning MAC Protocol for Energy Harvesting and Spectrum Access in Cognitive Radio Sensor Networks

The fusion of Wireless Sensor Networks (WSNs) and Cognitive Radio Networks (CRNs) into Cognitive Radio Sensor Networks (CRSNs) is quite an attractive proposal, because it allows a distributed set of low-powered sensor nodes to opportunistically access spectrum bands that are underutilized by their licensed owners (called primary users (PUs)). In addition, when the PUs are actively transmitting in their own bands, sensor nodes can switch to energy harvesting mode to obtain their energy needs (for free), to achieve almost perpetual life. In this work, we present a novel and fully distributed MAC protocol, called S-LEARN, that allows sensor nodes in a CRSN to entwine their RF energy harvesting and data transmission activities, while intelligently addressing the issue of disproportionate difference between the high power necessary for the node to transmit data packets and the small amount of power it can harvest wirelessly from the environment. The presented MAC protocol can improve both the network throughput and total harvested energy, while being robust to changes in the network configuration. Moreover, S-LEARN can keep the cost of the system low, and it avoids the pitfalls from which centralized systems suffer