Empirical tests developed for an objective evaluation of noodle texture as well as sensory methods provide no information about the rheological parameters responsible for differences in the texture of Asian noodles. Therefore, there is a need for a technique to evaluate the rheological properties of Asian noodles that is fast, easy and inexpensive. Promising results from ultrasonic assessments of the rheological properties of wheat flour doughs and preliminary noodle studies were an encouragement to use ultrasound to address such need in this thesis. Using ultrasound at a relatively high frequency (1.4 MHz), the rheological properties of raw noodles made with three Canadian wheat varieties at various barley β-glucan (BBG) contents, sheeting work input levels and salt to kansui ratios (formulas) were evaluated. Conventional rheological, i.e., stress relaxation (SR) and uniaxial extension (Kieffer), measurements were employed for comparison purposes. The capability of ultrasound for evaluating the effects of BBG addition and sheeting work input on the rheological properties of raw wheat noodles of this study was confirmed. A greater sensitivity of ultrasound to microscopic changes in noodle dough structure, compared to SR and Kieffer tests, was reflected in differences between the results of ultrasound and those of the SR and Kieffer tests with respect to the influences of flour variety and formula on noodle rheology. Investigations of the density of raw noodles showed that air bubbles were present in the noodle dough matrix. A simple, fast and low-cost method, based on the measurement of noodle dough dimensions during the sheeting process, was proposed for a quick evaluation of noodle dough rheology. The results of the proposed method were in agreement with those of conventional rheological measurements on the effects of flour variety and sheeting work input on noodle texture. The time-dependent effect of kansui on noodle dough structure was confirmed by comparing the results of this new method with those of SR and Kieffer tests with respect to the effect of formula on noodle rheology. Further investigations are proposed to establish this method for quick assessment of Asian wheat noodle rheology. / February 2017

An investigation has been carried out into the rheology of chocolate in relation to its flow and mixing features in a real industrial environment. The chocolate manufacturing plant of Rowntree at York provided a base for this study. The project aims were: a) to measure the viscous and time dependent properties of chocolate. b) to explain the observed flow properties in relation to the constituents of chocolate. c) to determine the shear rate which, for a given recipe, yields a minimum stable viscosity (of particular commercial value). d) to assess the type of mixer able to provide this duty. The experimental work involved rheological studies with concentric cylinder and tubular viscometers, operated to measure viscosity as a function of shear rate and shearing time. The chocolate samples studied were taken from various points in the manufacture process at Rowntree, York. Model chocolate systems were made from cocoa liquor, and sugar with cocoa butter, which were studied to underpin the basic mechanisms of the flow properties of the total chocolate. Shear thinning in milk chocolate has been shown to be accounted for by surface coating and fat release from the cocoa cellular material. Analysis of the sugar and cocoa butter system gave large hysteresis loops which may be explained as due to agglomeration of the sugar particles. The level of hysteresis was found to be related to the polarity of the liquid phase, such that a more polar fluid results in less hysteresis. Laboratory experiments have revealed that the level of work input to give permanent viscosity reduction for milk chocolate is dependent on the measuring shear rate. The level of optimum shear input for the measuring range 10 to 130 sec 1 is 645 sec for 30 minutes. The apparent viscosity measured at lower shear rates requires much longer ([approx]100 minutes).

An investigation has been carried out into the rheology of chocolate in relation to its flow and mixing features in a real industrial environment. The chocolate manufacturing plant of Rowntree at York provided a base for this study. The project aims were: a) to measure the viscous and time dependent properties of chocolate. b) to explain the observed flow properties in relation to the constituents of chocolate. c) to determine the shear rate which, for a given recipe, yields a minimum stable viscosity (of particular commercial value). d) to assess the type of mixer able to provide this duty. The experimental work involved rheological studies with concentric cylinder and tubular viscometers, operated to measure viscosity as a function of shear rate and shearing time. The chocolate samples studied were taken from various points in the manufacture process at Rowntree, York. Model chocolate systems were made from cocoa liquor, and sugar with cocoa butter, which were studied to underpin the basic mechanisms of the flow properties of the total chocolate. Shear thinning in milk chocolate has been shown to be accounted for by surface coating and fat release from the cocoa cellular material. Analysis of the sugar and cocoa butter system gave large hysteresis loops which may be explained as due to agglomeration of the sugar particles. The level of hysteresis was found to be related to the polarity of the liquid phase, such that a more polar fluid results in less hysteresis. Laboratory experiments have revealed that the level of work input to give permanent viscosity reduction for milk chocolate is dependent on the measuring shear rate. The level of optimum shear input for the measuring range 10 to 130 sec 1 is 645 sec for 30 minutes. The apparent viscosity measured at lower shear rates requires much longer ([approx]100 minutes). / Yorkreco, Nester York Ltd.

<p>One of the big problems of the Swedish nine-year compulsory school is the large number of pupils who fail to achieve a satisfactory standard in mathematics. One explanation that has been increasingly considered over the last ten years is that the pupils have dyscalculia. Some research suggests that 6 per cent of compulsory school pupils suffer from this dysfunction, which would in that case make it one of the Swedish school’s greatest teaching problems.</p><p>The purpose of this thesis is to examine this problem area from two aspects. First of all by examining the concept of dyscalculia by means of a review of the literature from 1992 onwards. The second perspective has as its starting point a case study where the purpose was to give a detailed picture of the pupil with mathematics problems. The latter part of the study was carried out over a six-year period when 200 pupils, 13 of them with particular mathematics problems, were studied in detail.</p><p>A point of departure for the study was provided by a large database where as much information as possible was collected about pupils from Year 5 of the nine-year compulsory school to Year 2 of the three-year upper secondary school. The pupils were asked to fill in regular questionnaires and classroom observations were made of roughly 100 mathematics lessons, 40 of which were recorded on video. Finally there were in-depth interviews of the 13 pupils on two occasions, the final one being during Year 2 of the upper secondary school.</p><p>The review of the research showed a series of dubious and indistinct circumstances surrounding the dyscalculia concept, and also ambiguity with regard to the diagnosis of dyscalculia. The conclusion of the review was that the concept of dyscalculia ought at present to be used with great caution, or perhaps not at all. Admittedly the review does not provide grounds for totally dismissing the dyscalculia concept, but as long as it remains impossible to determine the concept unambiguously, and I have not been able to do this in the course of this study, there are no good scientific grounds for using the term dyscalculia in practice.</p><p>The empirical study shows the complexity of the problem area. Both the causes suggested by the pupils as the origin of the problem and the measures that helped them to obtain their mathematics grades form a complex pattern. The low work input of the pupils during mathematics lessons, an unsettled working environment, large classes, problems of stress and anxiety prior to tests, and obstructive gender patterns are among the causes suggested by the pupils as explanations of the occurrence of the mathematics problems. Good teachers, in other words teachers who can explain, set limits and give encouragement, were a significant factor in reversing the downward trend. Positive experiences of school changes, where the pupil felt that he or she could start again from the beginning, were also mentioned as significant by several pupils. Collaboration with fellow-pupils and the fact that the pupils themselves decided to get to grips with the problems were other important reasons for the change. The prospects of students with specific problems in mathematics nevertheless being able to leave compulsory school with satisfactory grades appear, however, from the results of this study, to be bright. All the pupils left the compulsory school with satisfactory mathematics grades and also completed mathematics studies at upper secondary school, despite major problems in the subject at intermediate school (age 10-13) stage.</p><p>The study indicates the need for research closer to the actual practical situation and to the importance of emphasizing good examples in practice. As the students themselves emphasize discrete communication between them as significant in the subject of mathematics, this is also an important area for future research.</p>

One of the big problems of the Swedish nine-year compulsory school is the large number of pupils who fail to achieve a satisfactory standard in mathematics. One explanation that has been increasingly considered over the last ten years is that the pupils have dyscalculia. Some research suggests that 6 per cent of compulsory school pupils suffer from this dysfunction, which would in that case make it one of the Swedish school’s greatest teaching problems. The purpose of this thesis is to examine this problem area from two aspects. First of all by examining the concept of dyscalculia by means of a review of the literature from 1992 onwards. The second perspective has as its starting point a case study where the purpose was to give a detailed picture of the pupil with mathematics problems. The latter part of the study was carried out over a six-year period when 200 pupils, 13 of them with particular mathematics problems, were studied in detail. A point of departure for the study was provided by a large database where as much information as possible was collected about pupils from Year 5 of the nine-year compulsory school to Year 2 of the three-year upper secondary school. The pupils were asked to fill in regular questionnaires and classroom observations were made of roughly 100 mathematics lessons, 40 of which were recorded on video. Finally there were in-depth interviews of the 13 pupils on two occasions, the final one being during Year 2 of the upper secondary school. The review of the research showed a series of dubious and indistinct circumstances surrounding the dyscalculia concept, and also ambiguity with regard to the diagnosis of dyscalculia. The conclusion of the review was that the concept of dyscalculia ought at present to be used with great caution, or perhaps not at all. Admittedly the review does not provide grounds for totally dismissing the dyscalculia concept, but as long as it remains impossible to determine the concept unambiguously, and I have not been able to do this in the course of this study, there are no good scientific grounds for using the term dyscalculia in practice. The empirical study shows the complexity of the problem area. Both the causes suggested by the pupils as the origin of the problem and the measures that helped them to obtain their mathematics grades form a complex pattern. The low work input of the pupils during mathematics lessons, an unsettled working environment, large classes, problems of stress and anxiety prior to tests, and obstructive gender patterns are among the causes suggested by the pupils as explanations of the occurrence of the mathematics problems. Good teachers, in other words teachers who can explain, set limits and give encouragement, were a significant factor in reversing the downward trend. Positive experiences of school changes, where the pupil felt that he or she could start again from the beginning, were also mentioned as significant by several pupils. Collaboration with fellow-pupils and the fact that the pupils themselves decided to get to grips with the problems were other important reasons for the change. The prospects of students with specific problems in mathematics nevertheless being able to leave compulsory school with satisfactory grades appear, however, from the results of this study, to be bright. All the pupils left the compulsory school with satisfactory mathematics grades and also completed mathematics studies at upper secondary school, despite major problems in the subject at intermediate school (age 10-13) stage. The study indicates the need for research closer to the actual practical situation and to the importance of emphasizing good examples in practice. As the students themselves emphasize discrete communication between them as significant in the subject of mathematics, this is also an important area for future research.