Synthesis of Sorbitol Fatty Acid Ester through Esterification of Sorbitol and Azelaic Acid Catalysed by Germanium (IV) Oxide

Conventionally, polyurethane (PU) is produced using polyol polyester derived from non-renewable petroleum feedstock. In addition to the restricted resources of petroleum feedstock, inefficient disposal of the non-biodegradable petroleum-based PU waste through landfill and incineration has caused environmental problem. [1]. As an alternative for the current resource, bio-based polyol polyester such as sorbitol fatty acid ester is introduced. Commonly, homogeneous acid catalyst such as sulfuric acid is used in esterification process for the synthesis of polyol polyester [2, 3]. In this study, sorbitol (SL) and azelaic acid (AA) derived from renewable resources were used in the esterification reaction to produce bio-based polyol polyester. Germanium (IV) oxide, a heterogeneous acid catalyst was chosen to eliminate the use of homogeneous acid catalyst that renders corrosiveness, difficulty in the downstream separation and catalyst reuse [4, 5]. The effects of important operating parameters include reaction temperature (160˚C to 220˚C), molar ratio of SL/AA (1:1 to 4:1) and catalyst loading (1 to 4 vol%) were investigated. The reaction was carried out in a batch reactor and the products were analyzed for its acid value through titration and concentration sorbitol and its anhydrides through gas chromatography (GC)

Quantum Teleportation from a Propagating Photon to a Solid-State Spin Qubit

The realization of a quantum interface between a propagating photon used for transmission of quantum information, and a stationary qubit used for storage and manipulation, has long been an outstanding goal in quantum information science. A method for implementing such an interface between dissimilar qubits is quantum teleportation, which has attracted considerable interest not only as a versatile quantum-state-transfer method but also as a quantum computational primitive. Here, we experimentally demonstrate transfer of quantum information carried by a photonic qubit to a quantum dot spin qubit using quantum teleportation. In our experiment, a single photon in a superposition state of two colors -- a photonic qubit is generated using selective resonant excitation of a neutral quantum dot. We achieve an unprecedented degree of indistinguishability of single photons from different quantum dots by using local electric and magnetic field control. To teleport a photonic qubit, we generate an entangled spin-photon state in a second quantum dot located 5 meters away from the first and interfere the photons from the two dots in a Hong-Ou-Mandel set-up. A coincidence detection at the output of the interferometer heralds successful teleportation, which we verify by measuring the resulting spin state after its coherence time is prolonged by an optical spin-echo pulse sequence. The demonstration of successful inter-conversion of photonic and semiconductor spin qubits constitute a major step towards the realization of on-chip quantum networks based on semiconductor nano-structures.Comment: 12 pages, 3 figures, Comments welcom

Influence of Promoter Type on Bimetallic Co-Ni/Al 2O3 Catalyst for Steam Reforming of Glycerol

Biodiesel is produced from a variety of renewable sources including waste cooking oil. However, its production has led to a glut of glycerol (a by-product, in the amount of 1 mol of glycerol for every three of fatty acid methyl esters). Glycerol presently has low-level and limited use in pharmaceuticals production. The present work deals with steam reforming of glycerol over a bimetallic Co-Ni/Al2O3 catalyst system promoted by 2.5wt% alkaline earth oxides (AEO) and lanthanide oxides (LO). The addition of metal oxide from these two groups reportedly minimizes carbon deposition with possible improvement in product selectivity and syngas production rate. Our objective was to provide a systematic correlation between physicochemical properties of the promoted catalyst and reaction metrics

The relationship between the cranial base and jaw base in a Chinese population

published_or_final_versio

Organisational transformation through CRM implementation: a descriptive case study

CRM is becoming critical to organisations worldwide as global competition increases and technological innovations in communication continue to emerge. In this descriptive case study, we have investigated a utility provider &ndash; with a geographical monopoly, who has successfully implemented a complaint management system, as part of their CRM process transformation. We have applied the teleological process theory (Ven de Ven and Poole 1995) to describe the organisational change, based on our empirical research.<br /

Analytical and experimental study of stratification and liquid-ullage coupling, 1 June 1964 - 31 May 1965

Closed-form solution for stratification of subcooled fluids in containers subjected to heating, and for liquid-ullage vapor couplin

High yield of isosorbide production from sorbitol dehydration catalysed by amberlyst 36

Isosorbide (ISB), one of the important polyols, can be produced through the sequential intramolecular dehydration of sorbitol derived from abundance renewable biomass resource. The advantages of its rigid structure has granted the ISB a wide application in the polymer industries. Acidic catalyst in liquid phase was conventionally used in the dehydration process. This homogeneous catalysed reaction gave low ISB yield and required additional downstream processes to separate catalyst. The present study employed solid acidic ion exchange resin, Amberlyst 36 in the sorbitol dehydration at a mild condition. The effect of important operating parameters such as stirring speed, catalyst loading, temperature and reaction time was investigated. The increase of catalyst loading from 5 wt% to 7 wt% did not significantly affect the ISB yield. A higher temperature increased the reaction rate whereas a prolonged reaction time (4h) increased the conversion of sorbitol and yield of ISB to the maximum. Both sorbitol conversion and ISB yield of >99% were recorded after a 4-hr reaction at the reaction temperature of 150°C, catalyst loading of 5wt% and stirring speed of 300rpm. The reaction kinetics was evaluated under a mass transfer resistances free condition at the reaction temperature ranged from 100°C to 150°C