Machining is a mechanical process where excess material from a work is removed to produce a product. At the moment different ferrous, non-ferrous materials and industrial blue wax have been used for prototype models. ...Machining is a mechanical process where excess material from a work is removed to produce a product. At the moment different ferrous, non-ferrous materials and industrial blue wax have been used for prototype models. However such materials is very expensive. Hence an attempt is made to substitute these materials by the palm oil based bio-wax produced in Malaysia. In this research, the authors will analyze and investigate whether there is a possibility to use the palm oil based bio-wax material to substitute with the petroleum based industrial-wax. Experimental analyses are carried out to investigate the capability and the strength of the palm oil based bio-wax material. The matrix blends were prepared of fatty acids from oleo-chemicals, palm oil wax, natural ash fibre and low linear density polyethylene （LLDPE） by stirring and melt-mixing. Sample b!ends are machined with lathe machining process. The sample blends showed there was no built edge formation and good smooth surface production.展开更多
Adsorption processes have received special attention for contaminants removal thanks to their capability to gen- erate effluents with high quality as well as their simple design. In the current work, the agro-waste re...Adsorption processes have received special attention for contaminants removal thanks to their capability to gen- erate effluents with high quality as well as their simple design. In the current work, the agro-waste residue avo- cado peel is proposed to be used as alternative to conventional activated carbons whose use is sometimes restricted to high costs, upgraded by their exhausting after long term operations. The carbonization procedure was optimized and analyzed through factorial design and response surface methodology by evaluating temper- ature （400-900 ℃） and time （30-90 min） effects： optimal conditions were found at 900℃ and 65 min, gener- ating an adsorbent with 87.52 m2.g 1 of BET surface area, a mesopore volume of 74% and a zero point charge at 8.6. The feasibility of the carbonaceous material was proved for the removal of a variety of dyes by investigating substrate （10-50 mg.L 1） and solid （0.5-20 g.L-1） concentration effects and statistical significance： complete removal of Naphthol Blue Black and Reactive Black 5 was reached under optimal conditions （10 mg.L 1 and 20g.L 1 of dye and solid, respectively）, while Basic Blue 41 was eliminated by using 13.4 g. L- 1 of the adsorbent. Overall, dyes removal by adsorption on carbonized avocado peel is presented as a promising technology due to the low cost and easy availability of the precursor, as well as the straightforward generation, the satisfactory char- acteristics and the proved adsorption capacity of the adsorbent.展开更多
This paper is aimed at verifying utilization possibilities of alkaline modified coal fly ash as cement replacement in the concrete. The influence of alkaline activated coal fly ash originating from Slovakian power pla...This paper is aimed at verifying utilization possibilities of alkaline modified coal fly ash as cement replacement in the concrete. The influence of alkaline activated coal fly ash originating from Slovakian power plant in Novsky （Si/Al = 3,1） as a partial cement replacement in concrete on compressive strength of hardened composites after 28 and 90 days was investigated. Alkaline activation of coal fly ash was realized in an autoclave at 130 ℃ and pressure of 160 kPa during 5 hours and in a reactor under normal conditions （equal temperature during 36 hours） at solid/liquid ratio of 0.5. Coal fly ash/cement mixtures were prepared with 25 % cement replacement by starting and modified coal fly ash and given in forms. Compressive strengths of composites after 28 and 90 days of hardening were compared to referential composite without coal fly ash and evaluated according to the standard of STN EN 450 by the value of relative strength KR （compressive strength of coal fly ash/cement composite to compressive strength of comparative concrete）. The final compressive strengths of hardened composites based on alkaline activated coal fly ash reached values in the range of 6 up to 50 MPa. In the set of experimental composites based on alkaline activated coal fly ashes, the highest value of relative strength after 28- and 90- days of hardening reached composite with cement replacement by coal fly ash zeolitized in autoclave （105% of compressive strength of referential sample）, what is connected with formation of zeolitic phases on surface of coal fly ash particles. The achieved results confirm that alkaline activation of coal fly ash in an autoclave under observed conditions can be successfully used as a partial cement replacement in concrete of C20/25 and C25/30 in accordance with requirements of standards （STN EN 450 and STN EN 206）.展开更多
The adoption of grammatical modifier for im- plants or other kinds of biomaterials eventually absorbed by the body has been a long-standing confusing issue, and there are diverse terms in the large fields of research,...The adoption of grammatical modifier for im- plants or other kinds of biomaterials eventually absorbed by the body has been a long-standing confusing issue, and there are diverse terms in the large fields of research, which not only causes the difficulties when searching on the Internet, but also blurs the meaning and boundaries for researchers. Prior unification attempts at laws/standards set the basis for such research fields towards researching, labeling, marketing and instructions for use. Considering this, the typical gram- matical modifiers ＂biodegradable＂, ＂resorbable＂ ＂absorbable＂, along with their noun forms used in the decades of scien- tific research have been reviewed and explained, interdiscipli- nary in chemistry, ecology, materials science, biology, micro- biology, medicine, and based on usage customs, laws, stan- dards and markets. The term ＂biodegradable＂ has been not only used in biomaterials but also in ecology waste manage- ment, biomedicine and even natural environment. Mean- while, the term ＂resorbable＂ has long been used in biological reaction （osteoclast driven bone resorption）, but is inappro- priate for implants that do not carry the potential to grow back into their original form. The term ＂absorbable＂ focuses more on the host metabolism to the foreign biodegradation products of the implanted material/device compared with the term ＂degradable/biodegradable＂. Meanwhile the coherence and normalization of the term ＂absorbable＂ carried by its own in laws and standards contributes as well. In general, the au- thors consider the term ＂absorbable＂ to be the best grammat- ical modifier with respect to other adjectives which share the same inherence. A further internationally unified usage is proposed by us.展开更多
文摘Machining is a mechanical process where excess material from a work is removed to produce a product. At the moment different ferrous, non-ferrous materials and industrial blue wax have been used for prototype models. However such materials is very expensive. Hence an attempt is made to substitute these materials by the palm oil based bio-wax produced in Malaysia. In this research, the authors will analyze and investigate whether there is a possibility to use the palm oil based bio-wax material to substitute with the petroleum based industrial-wax. Experimental analyses are carried out to investigate the capability and the strength of the palm oil based bio-wax material. The matrix blends were prepared of fatty acids from oleo-chemicals, palm oil wax, natural ash fibre and low linear density polyethylene （LLDPE） by stirring and melt-mixing. Sample b!ends are machined with lathe machining process. The sample blends showed there was no built edge formation and good smooth surface production.
基金financial support from the Dirección General de Investigación y Postgrado(DGIPProject 271459),Universidad Técnica Federico Santa María
文摘Adsorption processes have received special attention for contaminants removal thanks to their capability to gen- erate effluents with high quality as well as their simple design. In the current work, the agro-waste residue avo- cado peel is proposed to be used as alternative to conventional activated carbons whose use is sometimes restricted to high costs, upgraded by their exhausting after long term operations. The carbonization procedure was optimized and analyzed through factorial design and response surface methodology by evaluating temper- ature （400-900 ℃） and time （30-90 min） effects： optimal conditions were found at 900℃ and 65 min, gener- ating an adsorbent with 87.52 m2.g 1 of BET surface area, a mesopore volume of 74% and a zero point charge at 8.6. The feasibility of the carbonaceous material was proved for the removal of a variety of dyes by investigating substrate （10-50 mg.L 1） and solid （0.5-20 g.L-1） concentration effects and statistical significance： complete removal of Naphthol Blue Black and Reactive Black 5 was reached under optimal conditions （10 mg.L 1 and 20g.L 1 of dye and solid, respectively）, while Basic Blue 41 was eliminated by using 13.4 g. L- 1 of the adsorbent. Overall, dyes removal by adsorption on carbonized avocado peel is presented as a promising technology due to the low cost and easy availability of the precursor, as well as the straightforward generation, the satisfactory char- acteristics and the proved adsorption capacity of the adsorbent.
文摘This paper is aimed at verifying utilization possibilities of alkaline modified coal fly ash as cement replacement in the concrete. The influence of alkaline activated coal fly ash originating from Slovakian power plant in Novsky （Si/Al = 3,1） as a partial cement replacement in concrete on compressive strength of hardened composites after 28 and 90 days was investigated. Alkaline activation of coal fly ash was realized in an autoclave at 130 ℃ and pressure of 160 kPa during 5 hours and in a reactor under normal conditions （equal temperature during 36 hours） at solid/liquid ratio of 0.5. Coal fly ash/cement mixtures were prepared with 25 % cement replacement by starting and modified coal fly ash and given in forms. Compressive strengths of composites after 28 and 90 days of hardening were compared to referential composite without coal fly ash and evaluated according to the standard of STN EN 450 by the value of relative strength KR （compressive strength of coal fly ash/cement composite to compressive strength of comparative concrete）. The final compressive strengths of hardened composites based on alkaline activated coal fly ash reached values in the range of 6 up to 50 MPa. In the set of experimental composites based on alkaline activated coal fly ashes, the highest value of relative strength after 28- and 90- days of hardening reached composite with cement replacement by coal fly ash zeolitized in autoclave （105% of compressive strength of referential sample）, what is connected with formation of zeolitic phases on surface of coal fly ash particles. The achieved results confirm that alkaline activation of coal fly ash in an autoclave under observed conditions can be successfully used as a partial cement replacement in concrete of C20/25 and C25/30 in accordance with requirements of standards （STN EN 450 and STN EN 206）.
基金supported by the National Key Research and Development Program of China (2016YFC1102402)National Natural Science Foundation of China (NSFC, 51431002)the NSFC and the Research Grants Council (RGC) of Hong Kong Joint Research Scheme (51361165101 and 5161101031)
文摘The adoption of grammatical modifier for im- plants or other kinds of biomaterials eventually absorbed by the body has been a long-standing confusing issue, and there are diverse terms in the large fields of research, which not only causes the difficulties when searching on the Internet, but also blurs the meaning and boundaries for researchers. Prior unification attempts at laws/standards set the basis for such research fields towards researching, labeling, marketing and instructions for use. Considering this, the typical gram- matical modifiers ＂biodegradable＂, ＂resorbable＂ ＂absorbable＂, along with their noun forms used in the decades of scien- tific research have been reviewed and explained, interdiscipli- nary in chemistry, ecology, materials science, biology, micro- biology, medicine, and based on usage customs, laws, stan- dards and markets. The term ＂biodegradable＂ has been not only used in biomaterials but also in ecology waste manage- ment, biomedicine and even natural environment. Mean- while, the term ＂resorbable＂ has long been used in biological reaction （osteoclast driven bone resorption）, but is inappro- priate for implants that do not carry the potential to grow back into their original form. The term ＂absorbable＂ focuses more on the host metabolism to the foreign biodegradation products of the implanted material/device compared with the term ＂degradable/biodegradable＂. Meanwhile the coherence and normalization of the term ＂absorbable＂ carried by its own in laws and standards contributes as well. In general, the au- thors consider the term ＂absorbable＂ to be the best grammat- ical modifier with respect to other adjectives which share the same inherence. A further internationally unified usage is proposed by us.
