Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a l...Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy (LIBS) apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the 'drift' obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants.展开更多
Cassava has gained attention as a potential industrial crop. The roots are processed into cassava flour for bakery and confectioneries. With the ever increasingly expensive level of wheat flour import for bread produc...Cassava has gained attention as a potential industrial crop. The roots are processed into cassava flour for bakery and confectioneries. With the ever increasingly expensive level of wheat flour import for bread production in developing countries like Ghana, the need for other highly nutritious yet readily available and less expensive source of composite flour is important. <span style="font-family:Verdana;">The aim of the study was</span><span style="font-family:Verdana;"> to investigate consumer acceptability of bread developed from cassava flour and wheat flour. A 4</span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">×</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3 factorial design was used to develop bread samples (A = 100% wheat flour, control, B = 10% cassava flour + 90% wheat flour, C = 20% cassava flour +</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">80% wheat flour and </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">D</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> = 30% cassava flour + 70% wheat flour). Sensory evaluation was performed on the bread samples using the 9-point hedonic scale to evaluate sensory attributes like colour, gumminess, mouth-feel, taste, flavour, and overall acceptability. The proximate compositions of the products were also evaluated using the A. O. A. C (2005) official methods. Statistically, there was </span><span style="font-family:Verdana;">significant</span><span style="font-family:Verdana;"> difference among the protein and carbohydrate of all flour products developed. However, the energy content of products with 30% cassava flour replacement was significantly higher than other replicates. The control had the lowest moisture content of 17.5% with product 20% cassava flour replacement having the highest moisture content of 18.2%. In terms of overall </span><span style="font-family:Verdana;">acceptability</span><span style="font-family:Verdana;"> 10% cassava flour replaced bread was rated like extremely ahead of the control sample which was rated as like very much. These results showed that the 10 and 20% wheat/cassava composite flour bread recipe could be a viable alternative to achieve the desired economic, food security and health.</span></span></span></span>展开更多
基金supported by National Natural Science Foundation of China(Nos.61127017,61378047,61205216,61178009,61108030,61475093,and 61275213)the National Key Technology R&D Program of China(No.2013BAC14B01)+2 种基金the 973 Program of China(No.2012CB921603)the Shanxi Natural Science Foundation,China(Nos.2013021004-1,2012021022-1)the Shanxi Scholarship Council of China(Nos.2013-011 and 2013-01)
文摘Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy (LIBS) apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the 'drift' obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants.
文摘Cassava has gained attention as a potential industrial crop. The roots are processed into cassava flour for bakery and confectioneries. With the ever increasingly expensive level of wheat flour import for bread production in developing countries like Ghana, the need for other highly nutritious yet readily available and less expensive source of composite flour is important. <span style="font-family:Verdana;">The aim of the study was</span><span style="font-family:Verdana;"> to investigate consumer acceptability of bread developed from cassava flour and wheat flour. A 4</span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">×</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3 factorial design was used to develop bread samples (A = 100% wheat flour, control, B = 10% cassava flour + 90% wheat flour, C = 20% cassava flour +</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">80% wheat flour and </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">D</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> = 30% cassava flour + 70% wheat flour). Sensory evaluation was performed on the bread samples using the 9-point hedonic scale to evaluate sensory attributes like colour, gumminess, mouth-feel, taste, flavour, and overall acceptability. The proximate compositions of the products were also evaluated using the A. O. A. C (2005) official methods. Statistically, there was </span><span style="font-family:Verdana;">significant</span><span style="font-family:Verdana;"> difference among the protein and carbohydrate of all flour products developed. However, the energy content of products with 30% cassava flour replacement was significantly higher than other replicates. The control had the lowest moisture content of 17.5% with product 20% cassava flour replacement having the highest moisture content of 18.2%. In terms of overall </span><span style="font-family:Verdana;">acceptability</span><span style="font-family:Verdana;"> 10% cassava flour replaced bread was rated like extremely ahead of the control sample which was rated as like very much. These results showed that the 10 and 20% wheat/cassava composite flour bread recipe could be a viable alternative to achieve the desired economic, food security and health.</span></span></span></span>