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Two sets of formulations based on three copolymer and three terpolymer systems involving tributyltin methacrylate(BTMA),methyl methacrylate(MMA) and acrylonitrile (AN…
Two sets of formulations based on three copolymer and three terpolymer systems involving tributyltin methacrylate(BTMA),methyl methacrylate(MMA) and acrylonitrile (AN) with variable tin contents of 7, 15 and 22% were prepared. There is only one varient in each formulation of the six prepared, that is the type of organotin polymer whether it is a copolymer or terpolymer of a definite tin content 7 or 15 or 22%. The binder mixture is a blend consisting of the organotin polymer, a vinyl copolymer and its external plasticizer and little amount of rosin. A moderate and fixed amount of cuprous oxide was introduced into all formulations as a supplementary toxin with organotin polymer. Leaching rates of micro amounts of copper and tin were determined. Panel exposure test in the sea was performed at Port Said. Best antifouling efficiency was obtained from formultions containing organotin copolymer or terpolymer of 22% tin content and that containing organotin copolymer of 15% tin.
The effect of pigment filler and extender on the antifouling efficiency of six compositions containing organotin polymer is studied. The binder mixture is a blend…
The effect of pigment filler and extender on the antifouling efficiency of six compositions containing organotin polymer is studied. The binder mixture is a blend containing a copolymer of tri‐n‐butyltin methacrylate and methylmeth acrylate (OTP) with 22% tin content, a vinyl copolymer with its external plasticizer and little amount of rosin. Cuprous oxide was added as a supplementary toxin with the OTP. Leaching rates of microamounts of copper and tin were determined for a period of nearly one year applying standard techniques. Painted plates were immersed in Suez Canal waters at Port‐Said for more than 36 months. Comparison between different fillers and extenders on the antifouling behaviour of painted surfaces is shown. Compositions containing cellite and china clay exhibited the maximum antifouling performance.
To organotin polymer systems were prepared based on the reaction of tri‐n‐butyltin methacrylate with methyl methacrylate ad acrylonitrile. Tin content of the polymers was…
To organotin polymer systems were prepared based on the reaction of tri‐n‐butyltin methacrylate with methyl methacrylate ad acrylonitrile. Tin content of the polymers was about 22% and the physical properties of the organotin polymer films were investigated. The anti‐fouling potential of the prepared polymers was investigated as unpigmented and pigmented coatings at Alexandria and Port‐Said. Compositions containing vinyl copolymer as a co‐resin as well as cuprous oxide as a supporting toxin showed good antifouling performance for more than three years.
Three copolymer and three terpolymer systems involving tributyltin methacrylate, methyl methacrylate and acrylonitrile were prepared with variable tin content of 7, 15 and…
Three copolymer and three terpolymer systems involving tributyltin methacrylate, methyl methacrylate and acrylonitrile were prepared with variable tin content of 7, 15 and 22%. The structure of the organotin polymers was investigated by the elemental analysis of tin and nitrogen and by infrared spectroscopy. Long‐term leaching rate determinations of tin from the organotin polymer films were studied and were in the range of 0.033–0.045 ?g Sn/cm2/day. The antifouling performance of the prepared polymer varnishes was tested at Ismailia and at Alexandria. Tributyltin methacrylate‐methyl methacrylate copolymer with tin content of 22% exhibited the highest antifouling potential for more than 18 months.
An organotin copolymer with tin content of 22% was prepared by the reaction of methyl methacrylate and tri‐n‐butyltin methacrylate. The prepared copolymer was incorporated…
An organotin copolymer with tin content of 22% was prepared by the reaction of methyl methacrylate and tri‐n‐butyltin methacrylate. The prepared copolymer was incorporated into a paint formulation containing cuprous oxide as an external toxin. Laboratory evaluation of the formulation showed that the average value of the leaching rate of Cu was 7 µg/cm2/day, while the leaching rate of tin was found to be in the range of 0.033 µg/cm2/day. The antifouling performance of the prepared formulation was tested as painted areas on the hull of a trading ship. After about one year's running period through the Mediterranean and Red Sea harbours the tested areas showed good antifouling efficiency compared with the commercial antifouling paint.
Details the preparation of emulsion copolymerization of styrene (St)‐vinylacetate (VAc) with different molar ratio 33:67(A1), 50:50(A2) and 67:33(A3) using redox initiator…
Details the preparation of emulsion copolymerization of styrene (St)‐vinylacetate (VAc) with different molar ratio 33:67(A1), 50:50(A2) and 67:33(A3) using redox initiator system (k2S208/NaHS03) and investigates their film forming. Finds that the drying film characterization took on a brittle property which is attributed to the nature of styrene polymers. Explains that molar ratio 67:33 from butyl acrylate (BuA‐VAc) and vinyl acetate (B1, B2 and B3) in the presence of pluronic F87 was chosen as the coemulsifier as it gives good transparent and elastic film properties but has a tacky character owing to the nature of butyl acrylate polymer. Shows that styrene‐butylacrylate (St‐BuA) 67:33 molar ratio(C) has high conversion and a solid content of 51 per cent, and its film forming gives a transparent sheet that dries within 45 minutes. Notes that incorporation of these latices into interior and exterior coatings gives good characterization (hardness, ductility, adhesion and washability of 4,042 cycles) compared with the standard specifications for evaluation of latex paint.
The current status of nanotechnology research and development in Jordan is analyzed. In recent years, Jordanian institutions demonstrated considerable interest in the…
The current status of nanotechnology research and development in Jordan is analyzed. In recent years, Jordanian institutions demonstrated considerable interest in the development and production of nanotechnology. Here the purpose of this paper is to provide detailed information about the status of nanotechnology in Jordan in terms of several factors that influence selectivity in nanotechnology and the number of published peer-reviewed research articles.
Several factors that influence selectivity in nanotechnology and the number of published peer-reviewed research articles were analyzed. A detailed analysis of the collected data reveals that the number of publications, citations, and patents is highly dependent on the amount of research fund.
The development in nanotechnology is associated with presence and accessibility of sensitive laboratory equipment. The nanotechnology research output in Jordan is still lower than it should be due to the lack of necessary laboratory infrastructure. This is due to the insufficient funds allocated to scientific research, the restrictive access to available instruments and the bureaucracy of some governmental departments. Compared to some developed countries, Jordan is noticeably behind in developing a nanotechnology system of research and industry. It will take time as well as technical and financial resources in order to achieve an advanced level in the field of nanotechnology in Jordan. Nevertheless, many Jordanian researchers are doing their best and are producing some good research articles.
The many applications to the same approach.
Time and publications’ resources.
First comprehensive review ever. A base for researchers and decision makers.
This study aims to propose a model of entrepreneurial microcredit support that could address the problem of entrepreneurial support provided by microfinance institutions…
This study aims to propose a model of entrepreneurial microcredit support that could address the problem of entrepreneurial support provided by microfinance institutions. This objective is justified by the need to produce scientific knowledge that could be of use to practitioners and political decision-makers who formulate and implement strategies of social inclusion and poverty reduction.
The study adopts a socio-constructivist research perspective. Social constructivism is a theoretical approach that posits that all social reality is constructed. In other words, individuals construct their knowledge of reality relative to their social setting. This justifies the use of the focus group to supplement and validate the data gathered in an individual interview. The socio-constructivist perspective allows us to better understand and develop knowledge based on the meaning that interviewees attribute to their experience. This perspective also justifies the choice of qualitative data collection method. The data were collected during semi-structured interviews.
Entrepreneurial microcredit support is distinguished from classic entrepreneurial support because it places the individual at the center of the process by emphasizing soft skills in the development of the entrepreneurial spirit. This approach engenders an efficient support process that comprises three main steps: determination of entrepreneurial potential, empowerment and reinforcement of autonomy and acquisition of managerial skills. The efficiency stems from the fact that the time factor is not a constraint in the entrepreneurial microcredit support process and from the relationship of proximity and trust between the credit agent and the micro-entrepreneur.
To the best of authors’ knowledge, this is the first paper to deal with the entrepreneurial microcredit support, which is completely different from the classical entrepreneurial support because of the uniqueness of microfinance and micro-entrepreneurs. The model clearly reveals that the support for the development of the skills required to successfully run a microenterprise is provided based on a socio-constructivist approach in which the micro-entrepreneur is the main actor in the construction of “mobilized knowledge” required to nurture promoters’ entrepreneurial spirit. Consideration of soft skills in a socio-constructivist perspective is, therefore, indispensable for entrepreneurial development.
In the increasingly competitive global economy, survival of an industry depends on catering to customer needs by quickly producing quality products and providing quality…
In the increasingly competitive global economy, survival of an industry depends on catering to customer needs by quickly producing quality products and providing quality service at an affordable price. In production, or in service, ergonomic considerations have manifested themselves in two distinct, yet related, domains. Focuses on the humans who contribute to product manufacture/service. It is frequently advocated that since humans are unreliable and less consistent, compared to machines, they are primarily responsible for lowering product and service quality. Ergonomic considerations, which, ironically, can improve human performance, are paid lip service during manufacturing system design. Compounding the problem is the current inability of most ergonomists to make ergonomic recommendations that do not run counter to the productivity and quality goals of system designers. Addresses these two issues by illustrating, through four case studies, the relationship between quality and variables that affect human performance.