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Copyright of Canadian Journal of Chemical Engineering is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Chemical Engineering is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Chemical Engineering is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Chemical Engineering is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Although bone tissue possesses the capacity for regenerative growth, the bone repair process is impaired in many clinical and pathological situations. For example massive bone loss caused by trauma and tumor resection as well as deformities require reconstructive surgery. In this context, there was a critical need to develop implant technologies to promote bone healing. Cortical and cancellous bone grafts are the materials of choice for bone filling or reconstruction, but their clinical use involves some difficulties. Septic complications, viral transmission and unavailability of native bone have therefore led to the development of synthetic bone substitutes. Allograft bone, or tissue harvested from a cadaver, while more readily available, may carry with it the risk of disease transmission and is also difficult to shape [1–3]. A significant additional limitation of allograft bone is the delayed remodeling by the host. In the case of very large defects, the allograft may remain in the implant site throughout the patient''s life, creating an area more prone to fracture or infection. The development of calcium phosphate ceramics and other related biomaterials for bone graft involved a better control of the process of biomaterials resorption and bone substitution. Synthetic bone graft materials available as alternatives to autogeneous bone for repair, substitution or augmentation, in particular synthetic biomaterials include, special glass ceramics described as bioactive glasses; calcium phosphates (calcium hydroxyapatite, HA; tricalcium phosphate, TCP; and biphasic calcium phosphate, BCP). These materials differ in composition and physical properties from each other and from bone; and must be take in consideration for more efficient bone ingrowth at the expense of the biomaterials and to adapt to new development of dedicated biomaterials. In the last decade synthetic calcium phosphate materials, principally calcium hydroxyapatite (HA) ceramics, was commercially used. However the concept of bioactivity (release of ions of biological interest) well described for glass c\ramic was not particularly take in account for HA and other related biomaterials(ACP Amorphous Calcium Phosphate, CdA Calcium Phosphate deficient Apatite). HA until recently was considered to be non able to be resorbed. Calcium phosphate biomaterials differ in their solubility or extent of dissolution: ACP> >α-TCP> >β-TCP>CdA> >ACP. These ceramics are osteoconductive (act as a support for new bone formation requiring the presence of porosity) and able to be resorbed (degradable through chemical and cellular processes). They are also biocompatible (do not induce adverse local tissue reaction, immunogenicity or systematically toxicity); and more recently, some papers report osteoinductive properties associated to the chemical nature (biphasic Ca P) and the microstruture. Past decade, these bioceramics have been marketed and approved for use in humans as bone substitutes. Various presentations are currently used in orthopaedic and maxillo-facial surgery such as wedges, blocks or granules. Owing to their bone substitution properties, CaP ceramics have naturally been considered as a potential matrix for tissue engineering and the development of a bioactive drug delivery system (DDS) in bone sites. The paper presents the current knowledge on Calcium phosphate bioceramics, Bone tissue engineering and Calcium Phosphate Drug Delivery. [Copyright &y& Elsevier]

Abstract: Extraction of silver by gels of sodium polyacrylic-polyacrylate acid. Application: elimination of chloride anions. The extraction of silver from diluted aqueous solutions by gels of sodium polyacrylic–polyacrylate acid was studied. The study of pH variations shows that the extraction is done by cation–cation exchange process. The highest loading of the gel by silver is obtained at R(moles of Ag+ fixed by the gel/moles of –COO(H, Na))=0.75. The silver gel loaded allows the recovery of ions chlorides from the aqueous solutions. To cite this article: E.H. Rifi et al., C. R. Chimie 8 (2005) . [Copyright &y& Elsevier]

The department of chemistry at the School of Engineering and Architecture of Fribourg has defined, after its integration into the University of Applied Sciences of Western Switzerland (HES-SO) two branches of development namely Computational and Industrial Chemistry (CIC) and Applied Chemistry (AC, regrouping analytical, organic and physical chemistry). Both of them fit well into the strategy of the HES-SO and respond to the requirements defined by the federal law on the Universities of Applied Sciences. In this article the development strategies for both branches are outlined and the human resources as well as the technical infrastructure required to implement these strategies are described.

Simulation tools and models are becoming more and more important in the fields of process development and design, process parameter optimization or in the evaluation of process interaction and their dynamic simulation. Not only can they be instrumental in creating cost transparency and ultimately reducing costs or shortening time to market, but they are also able to significantly accelerate progress in process development or lead to the identification of optimization potentials. The three lectures demonstrated the step-by-step use of a mass, energy and cost flow model, showed the application of simulation tools with varying level of detail at different stages of process design and further discussed the possibilities of using dynamic simulation within chemical production.

The Swiss chemical and pharmaceutical industry contributes about 5% to the gross domestic product of Switzerland. This is significantly above the levels seen in other European economies or in the USA. This industry employs about 68000 people in Switzerland and approximately 1350 'Chemiker FH', graduates of the Universities of Applied Science. About half of all employed 'Chemiker FH' graduates serve the industry in managerial positions while the other half play a vital role as technical or scientific specialists.The current evolution at universities throughout Europe towards Bachelor and Master degrees is an important process. 'Chemiker FH' graduates must be allowed equal opportunities in this respect while continuing to cultivate their competitive advantage to 'stay different' (gleichwertig aber andersartig). Well-educated and motivated staff will hereby continue to significantly contribute to a strong backbone of the chemical/pharmaceutical industry in Switzerland.

Production and modern research have already contributed towards development in many complex chemistry process. Our industry is still experiencing increased performance and technology demands. The speakers presented lectures on the latest developments in fractional layer crystallization, high-performance distillation, phosgene processes, front-end engineering, UV and electron beam crosslinking, and enantioselective chromatographic separations.

The chemical and biotechnological process industry is confronted with a time and capital consuming industrial reality in a more competitive environment. The need for leaner development and design of processes is increasing. Today and in the future, computer simulation is and will become an even more important tool for the development of new chemical or biotechnological processes and for the design of new plants. The objective of this one-day meeting was to review significant applications and technologies in this field. With the presentation of selected cases, we aimed to give a deeper insight in the working methods which should be used to get faster results and reduce development time and costs. The session should encourage a better understanding of the application of special software in industrial practice. Abstracts by the authors are given.

Various methods of bleaching in common use have been studied. Three types of aged paper (rag, chemical and mechanical woodpulp) were washed, deacidified, bleached, deacidified again and artificially aged. The physico-chemical effects of bleaching were measured by the degree of overbleaching, yellowing and loss of mechanical resistance as well as by analysis by electron microprobe and gel permeation chromatography. Seven methods were finally retained and their application is described in detail. [ABSTRACT FROM AUTHOR]