A method to determine volatile contaminants in polyethylene terephthalate (PET) packages by HDC-GC-FID and its application to post-consumer materials

A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations higher than 220 ng.g-1. The findings in this work corroborate data available in the scientific literature pointing out the suitability of the proposed analytical method.

Effect of adding unconventional raw materials on the technological properties of rice fresh pasta

The aim of this study was to develop fettuccini type rice fresh pasta by cold extrusion. To produce the pasta, a 2² Central Composite Rotational Design was used, in which the effects of the addition of pre-gelatinized rice flour - PGRF (0-60%) and modified egg albumin - MEA (0-10%) were studied. The dependent variables were the results of the cooking test and of the instrumental texture. The optimum cooking time for all of the formulations of rice fresh pasta was 3 minutes. MEA had a greater effect on increasing the weight of the pasta when compared to that of PGRF. It was found that with the addition of PGRF increase in loss of solids in cooking water, whereas MEA exerted the opposite effect on this parameter. Moreover, the maximum value of MEA (10%) had an optimum effect on pasta firmness, while PGRF had a negative effect on this parameter. The maximum values of PGRF and MEA reduced the stickiness of the pasta. Based on these results and on the parameters considered as most important, the rice pasta with the best technological characteristics was that with the maximum levels of MEA (10%) and no addition of PGRF (0%). This product was submitted to sensory and microbiological analyses, with good results.

Characterization of new sources of derivative starches as wall materials of essential oil by spray drying

Starch derivatives of taro (Colocasia esculenta L. Schott) and rice were characterized as wall materials of orange oil (d-limonene) by spray drying. Native starches were initially hydrolyzed with HCl and then esterified. Succinylated starches were modified using a conventional method in a slurry and were extruded; whereas, the phosphorylated starches were modified using the extrusion process. Viscosity and solubility of starches reduced after acid hydrolysis, derivatization, and extrusion. The particle size of the wall materials ranged between 20.05 and 31.81 µm. The encapsulation efficiency of the phosphorylated taro, rice, and waxy corn starches was 96.9, 96.8 and 97.1% respectively, and 98.6, 98.1, and 98.8% for succynilated taro, rice, and waxy corn starches, respectively. Starch derivatives of taro and rice could potentially be used as wall materials of orange oil d-limonene.

Effect of different covering materials used during the pre-harvest stage on the quality and storage life of 'Sultana Seedless' grapes

Covering the grapevine rows to delay the maturity and harvest date became widely practiced in 'Sultana Seedless' vineyards. The research work was conducted to test different cover materials (polypropylene cross-stitch, life pack, mogul and transparent polyethylene) in respect to their effects on grape quality and storability. Harvest was delayed for one month in covered plots. Harvested grapes were packed and transferred to storage rooms after pre-cooling. During packing, the grape clusters were sealed in PE bags with sulphur dioxide pads. The grapes were stored for 90 days in the first year and 120 days in the second year, at -0.5ºC and 90% RH. All the grape clusters were healthy and of marketable quality after 90 days of storage period. In the first year, at the end of the storage, only those grapes harvested from the rows covered with polypropylene cross-stitch showed fungal growth. The sensory quality scores revealed a lower level of preference after 120 days of storage. The effects of the covering materials tested were similar regarding grape quality and storage performance except the transparent polyethylene that damaged the grapevine leaves.

Sopeutumattomien oppilaiden tunne- ja itsesäätelytaitojen kehittyminen: Oppilaiden ja opettajien arvioita ja kokemuksia Aggression portaat -interventiosta

Tässä tutkimuksessa tarkastellaan sopeutumattomien erityisoppilaiden tunne- ja itsesäätelytaitojen kehittymistä Aggression portaat -interventio-ohjelman avulla kolmen vuoden tutkimusjakson aikana. Käsite sopeutumaton oppilas ei ole yksiselitteisesti määriteltävissä, mutta tässä tutkimuksessa sillä tarkoitetaan yleisopetussuunnitelman mukaan opiskelevaa oppilasta, joka käyttäytymiseen ja tunne-elämään liittyvien haasteidensa vuoksi on saanut siirron erityisopetuksen oppilaaksi ja saa enintään 10 oppilaan opetusryhmässä erityistä pedagogista tukea. Tutkimuksen yksi keskeinen tehtävä oli tutkia, onko tunne- ja itsesäätelytaitojen opettamisesta hyötyä sopeutumattomien oppilaiden tunteiden hallinnan ja käyttäytymisen itsesäätelyn kannalta. Tutkimuksen teoreettisena viitekehyksenä on Rose-Krasnorin (1997) malli yksilön sosioemotionaalisesta kompetenssista täydennettynä muiden tutkijoiden näkemyksillä. Sosioemotionaalinen kompetenssi on yläkäsite, johon kuuluvat alakäsitteinä tunne- ja itsesäätelytaidot, sosiokognitiiviset taidot ja sosiaaliset taidot. Lisäksi sosioemotionaaliseen kompetenssiin vaikuttavat kiintymyssuhteet ja osallisuus sekä tavoitteet vuorovaikutuksessa ja konteksti. Tässä tutkimuksessa keskitytään tunne- ja itsesäätelytaitoihin. Interventioryhmän (N=36) muodostivat Varsinais-Suomen alueella opiskelevat sopeutumattomien oppilaiden erityiskoulun 8-13-vuotiaat oppilaat, joille opetettiin tunne- ja itsesäätelytaitoja Aggression portaat -opetusmateriaaliin (Cacciatore 2007) pohjautuvan intervention avulla. Kontrolliryhmän (N=26) oppilaat olivat interventioryhmän oppilaiden ikäisiä ja he opiskelivat Varsinais-Suomen alueen kouluissa pienluokissa myös käyttäytymiseen ja tunne-elämään liittyvien haasteidensa vuoksi. Kontrolliryhmän oppilaat eivät saaneet tutkimusjakson aikana interventio-ohjelman mukaista opetusta. Interventioryhmän oppilaat kävivät erityiskoulua, jossa kaikilla oppilailla oli sopeutumisongelmia ja kontrolliryhmän oppilaat opiskelivat yleisopetuksen koulujen yhteydessä olevilla sopeutumattomien oppilaiden pienluokilla. Tutkimusaineisto on kerätty vuosina 2010-2012. Tutkimusmetodeina olivat sekä oppilaille että opettajille laaditut Webropol-alustaiset kyselyt ja oppilaiden kirjoittamat väkivalta-aiheiset tekstit. Tutkimus- ja kontrolliryhmän oppilaille pidettiin ”Tunteiden hallinta ja käyttäytyminen”- kyselyn avulla alkumittaus syksyllä 2009 ja mittaus toistettiin keväällä 2010, 2011 ja 2012. Kyselyiden avulla selvitettiin, miten oppilaiden tunteiden kokeminen ja ilmaiseminen sekä tunteiden hallinta ja käyttäytymisen itsesäätely muuttuivat tutkimusjakson aikana. Kyselyssä kartoitettiin myös oppilaiden kokemuksia kiusaamisena ilmenevästä väkivallasta. Aineistolähtöisen sisällönanalyysin avulla selvitettiin oppilaiden kirjoitelmista heidän ajatuksiaan ja näkemyksiään väkivallasta ja ehdotuksia keinoista väkivallan vähentämiseksi. Keväällä 2012 interventioryhmän oppilaille ja opettajille laadittujen erillisten kyselyiden avulla selvitettiin sekä oppilaiden että opettajien arvioita ja kokemuksia oppilaiden tunne- ja itsesäätelytaitojen muutoksesta interventio-ohjelman avulla. Lisäksi oppilaat ja opettajat arvioivat pidettyjen tunnetaitotuntien hyödyllisyyttä oppilaille. Interventioryhmän opettajat arvioivat myös Aggression portaat -interventiomateriaalin käyttökelpoisuutta. Vuoden 2014 Perusopetuksen opetussuunnitelman perusteissa esitetyt velvoitteet opettaa kouluissa oppilaille tunne- ja vuorovaikutustaitoja edellyttävät tietoa konkreettisista käytänteistä ja tutkimusperustaisista interventio-ohjelmista. Tämän tutkimuksen tulokset osoittavat, että interventioryhmän muodostaneet sopeutumattomat oppilaat hyötyivät Aggression portaat -interventiosta. Heidän tunne- ja itsesäätelytaidoissaan tapahtui myönteistä kehitystä etenkin myönteisten tunnekokemusten lisääntymisen ja toisiin kohdistuneen fyysisen väkivallan vähenemisen osalta. Myös suhtautuminen väkivaltapelien ikärajoihin oli merkittävästi myönteisempää kuin kontrolliryhmän oppilailla, joilla kielteinen asenne lisääntyi selvästi tutkimusjakson aikana. Lisäksi interventioryhmän oppilailla oli keinoja itsensä rentouttamiseksi, päinvastoin kuin kontrolliryhmän oppilailla, joilla keinottomuuden kokemus jopa lisääntyi. Interventioryhmän oppilaat suhtautuivat hyvin kielteisesti toisen yllyttämiseen väkivaltaiseen tekoon ja kirjoittivat enemmän ajatuksiaan väkivallasta tuoden esille runsaasti ehdotuksia keinoista väkivallan vähentämiseksi. Myös oppilaat ja opettajat kokivat interventio-ohjelman oppilaiden kehityksen kannalta hyödylliseksi ja opettajat myös interventiomateriaalin käyttökelpoiseksi.

University students’ regulation of learning and text processing – examples from medical and teacher education

The general aim of the thesis was to study university students’ learning from the perspective of regulation of learning and text processing. The data were collected from the two academic disciplines of medical and teacher education, which share the features of highly scheduled study, a multidisciplinary character, a complex relationship between theory and practice and a professional nature. Contemporary information society poses new challenges for learning, as it is not possible to learn all the information needed in a profession during a study programme. Therefore, it is increasingly important to learn how to think and learn independently, how to recognise gaps in and update one’s knowledge and how to deal with the huge amount of constantly changing information. In other words, it is critical to regulate one’s learning and to process text effectively. The thesis comprises five sub-studies that employed cross-sectional, longitudinal and experimental designs and multiple methods, from surveys to eye tracking. Study I examined the connections between students’ study orientations and the ways they regulate their learning. In total, 410 second-, fourth- and sixth-year medical students from two Finnish medical schools participated in the study by completing a questionnaire measuring both general study orientations and regulation strategies. The students were generally deeply oriented towards their studies. However, they regulated their studying externally. Several interesting and theoretically reasonable connections between the variables were found. For instance, self-regulation was positively correlated with deep orientation and achievement orientation and was negatively correlated with non-commitment. However, external regulation was likewise positively correlated with deep orientation and achievement orientation but also with surface orientation and systematic orientation. It is argued that external regulation might function as an effective coping strategy in the cognitively loaded medical curriculum. Study II focused on medical students’ regulation of learning and their conceptions of the learning environment in an innovative medical course where traditional lectures were combined wth problem-based learning (PBL) group work. First-year medical and dental students (N = 153) completed a questionnaire assessing their regulation strategies of learning and views about the PBL group work. The results indicated that external regulation and self-regulation of the learning content were the most typical regulation strategies among the participants. In line with previous studies, self-regulation wasconnected with study success. Strictly organised PBL sessions were not considered as useful as lectures, although the students’ views of the teacher/tutor and the group were mainly positive. Therefore, developers of teaching methods are challenged to think of new solutions that facilitate reflection of one’s learning and that improve the development of self-regulation. In Study III, a person-centred approach to studying regulation strategies was employed, in contrast to the traditional variable-centred approach used in Study I and Study II. The aim of Study III was to identify different regulation strategy profiles among medical students (N = 162) across time and to examine to what extent these profiles predict study success in preclinical studies. Four regulation strategy profiles were identified, and connections with study success were found. Students with the lowest self-regulation and with an increasing lack of regulation performed worse than the other groups. As the person-centred approach enables us to individualise students with diverse regulation patterns, it could be used in supporting student learning and in facilitating the early diagnosis of learning difficulties. In Study IV, 91 student teachers participated in a pre-test/post-test design where they answered open-ended questions about a complex science concept both before and after reading either a traditional, expository science text or a refutational text that prompted the reader to change his/her beliefs according to scientific beliefs about the phenomenon. The student teachers completed a questionnaire concerning their regulation and processing strategies. The results showed that the students’ understanding improved after text reading intervention and that refutational text promoted understanding better than the traditional text. Additionally, regulation and processing strategies were found to be connected with understanding the science phenomenon. A weak trend showed that weaker learners would benefit more from the refutational text. It seems that learners with effective learning strategies are able to pick out the relevant content regardless of the text type, whereas weaker learners might benefit from refutational parts that contrast the most typical misconceptions with scientific views. The purpose of Study V was to use eye tracking to determine how third-year medical studets (n = 39) and internal medicine residents (n = 13) read and solve patient case texts. The results revealed differences between medical students and residents in processing patient case texts; compared to the students, the residents were more accurate in their diagnoses and processed the texts significantly faster and with a lower number of fixations. Different reading patterns were also found. The observed differences between medical students and residents in processing patient case texts could be used in medical education to model expert reasoning and to teach how a good medical text should be constructed. The main findings of the thesis indicate that even among very selected student populations, such as high-achieving medical students or student teachers, there seems to be a lot of variation in regulation strategies of learning and text processing. As these learning strategies are related to successful studying, students enter educational programmes with rather different chances of managing and achieving success. Further, the ways of engaging in learning seldom centre on a single strategy or approach; rather, students seem to combine several strategies to a certain degree. Sometimes, it can be a matter of perspective of which way of learning can be considered best; therefore, the reality of studying in higher education is often more complicated than the simplistic view of self-regulation as a good quality and external regulation as a harmful quality. The beginning of university studies may be stressful for many, as the gap between high school and university studies is huge and those strategies that were adequate during high school might not work as well in higher education. Therefore, it is important to map students’ learning strategies and to encourage them to engage in using high-quality learning strategies from the beginning. Instead of separate courses on learning skills, the integration of these skills into course contents should be considered. Furthermore, learning complex scientific phenomena could be facilitated by paying attention to high-quality learning materials and texts and other support from the learning environment also in the university. Eye tracking seems to have great potential in evaluating performance and growing diagnostic expertise in text processing, although more research using texts as stimulus is needed. Both medical and teacher education programmes and the professions themselves are challenging in terms of their multidisciplinary nature and increasing amounts of information and therefore require good lifelong learning skills during the study period and later in work life.

Cardiovascular health risk profiling of Niagara Region grade 9 students : implications for elementary curriculum /

The purpose of this study was to determine if Ontario's health and physical education curriculum contributes sufficiently to ensure the health of our children and young adults. To determine the curriculum effect, the health risk profile of Niagara Region's grade 9 students was compared to Canada's adolescent population. All subjects completed a "Heart Health Lifestyle" survey and were measured for height, weight, percent body fat, blood pressure, and total cholesterol and performed the 20-metre shuttle run test as part of their physical and health education classes. The Niagara Region grade 9 population had a healthy risk profile. Aerobic power was inversely related, and cholesterol levels were positively associated to body mass index and percent body fat in the whole group analysis. These results indicate that physical education can offer unique and essential aspects allowing individuals a means to learn and control body movements and keep physically fit while providing protection against modern disease. Ontario's health and physical education curriculum does contribute to the health of our children and adolescents; however, there is a need to implement a stronger mandate for daily vigorous physical activity.

An exploration of the experience of implementing the second step violence prevention curriculum in one primary general learning disabilities class /

Violence has always been a part of the human experience, and therefore, a popular topic for research. It is a controversial issue, mostly because the possible sources of violent behaviour are so varied, encompassing both biological and environmental factors. However, very little disagreement is found regarding the severity of this societal problem. Most researchers agree that the number and intensity of aggressive acts among adults and children is growing. Not surprisingly, many educational policies, programs, and curricula have been developed to address this concern. The research favours programs which address the root causes of violence and seek to prevent rather than provide consequences for the undesirable behaviour. But what makes a violence prevention program effective? How should educators choose among the many curricula on the market? After reviewing the literature surrounding violence prevention programs and their effectiveness, The Second Step Violence Prevention Curriculum surfaced as unique in many ways. It was designed to address the root causes of violence in an active, student-centred way. Empathy training, anger management, interpersonal cognitive problem solving, and behavioural social skills form the basis of this program. Published in 1992, the program has been the topic of limited research, almost entirely carried out using quantitative methodologies.The purpose of this study was to understand what happens when the Second Step Violence Prevention Curriculum is implemented with a group of students and teachers. I was not seeking a statistical correlation between the frequency of violence and program delivery, as in most prior research. Rather, I wished to gain a deeper understanding of the impact ofthe program through the eyes of the participants. The Second Step Program was taught to a small, primary level, general learning disabilities class by a teacher and student teacher. Data were gathered using interviews with the teachers, personal observations, staff reports, and my own journal. Common themes across the four types of data collection emerged during the study, and these themes were isolated and explored for meaning. Findings indicate that the program does not offer a "quick fix" to this serious problem. However, several important discoveries were made. The teachers feU that the program was effective despite a lack of concrete evidence to support this claim. They used the Second Step strategies outside their actual instructional time and felt it made them better educators and disciplinarians. The students did not display a marked change in their behaviour during or after the program implementation, but they were better able to speak about their actions, the source of their aggression, and the alternatives which were available. Although they were not yet transferring their knowledge into positive action,a heightened awareness was evident. Finally, staff reports and my own journal led me to a deeper understanding ofhow perception frames reality. The perception that the program was working led everyone to feel more empowered when a violent incident occurred, and efforts were made to address the cause rather than merely to offer consequences. A general feeling that we were addressing the problem in a productive way was prevalent among the staff and students involved. The findings from this investigation have many implications for research and practice. Further study into the realm of violence prevention is greatly needed, using a balance of quantitative and qualitative methodologies. Such a serious problem can only be effectively addressed with a greater understanding of its complexities. This study also demonstrates the overall positive impact of the Second Step Violence Prevention Curriculum and, therefore, supports its continued use in our schools.

Transforming curriculum leadership: vice principals in independent Christian elementary schools /

The literature on the vice principalship characterizes the position as one filled with clerical record keeping and student discipline and paints a picture of role conflict and general discontent. Research suggests that vice principals desire to take on a more significant role, specifically a role in curriculum leadership. Using open-ended interviews, a focus group interview, document analysis, and my research journal, I have explored the work ofa group of vice principals who have taken on the role of curriculum leader in independent Christian elementary schools in Ontario. When asked to explain their understanding of curriculum, the participants referred to written programs of study. However, their leadership activities reveal a broader understanding of curriculum as something that is in fact dynamic in nature. This leadership is enabled and shaped by their middle position on staff that combines the authority of an administrator and the credibility of a teacher. Although this dual identity creates tension, it also provides opportunities for genuine curriculum leadership. As middle leaders, the participants in this study often pull together or connect elements of the curriculum (teachers, principals, and programs) that have become separated. Such connective leadership is characterized by transformational (Van Brummelen, 2002) tendencies. This research suggests that the further along the continuum one goes from the understanding of curriculum as planned (Eisner, 1994) to acknowledging a lived curriculum (Aoki, 1993), the more transformational one's leadership style becomes.

The impact of scheduling on the implementation of the new Ontario curriculum: teachers' perceptions /

This qualitative study explored secondary teachers' perceptions of scheduling in relation to pedagogy, curriculum, and observation of student learning. Its objective was to determine the best way to organize the scheduling for the delivery of Ontario's new 4-year curriculum. Six participants were chosen. Two were teaching in a semestered timetable, 1 in a traditional timetable, and 3 had experience in both schedules. Participants related a pressure cooker "lived experience" with weaker students in the semester system experiencing a particularly harsh environment. The inadequate amount of time for review in content-heavy courses, gap scheduling problems, catch-up difficulties for students missing classes, and the fast pace of semestering are identified as factors negatively impacting on these students. Government testing adds to the pressure by shifting teachers' time and attention in the classroom from deeper learning to a superficial coverage of material, from curriculum as lived to curriculum as text to be covered. Scheduling choice should be available in public education to accommodate the needs of all students. Curriculum guidelines need to be revamped to reflect the content that teachers believe is necessary for a successful course delivery. Applied level courses need to be developed for students who are not academically inferior but learn differently.

Introducing e-learning in a large multisite academic health sciences centre: a case study of e-curriculum planning and educator support /

This qualitative study investigated how a team of 7 hospital educators collaborated to develop e-curriculum units to pilot for a newly acquired learning -r management system at a large, multisite academic health sciences centre. A case study approach was used to examine how the e-Curriculum Team was structured, how the educators worked together to develop strategies to better utilize e-leaming in their ovwi practice, what e-curriculum they chose to develop, and how they determined their priorities for e-curriculum development. It also inquired into how they planned to involve other educators in using e-leaming. One set of semistructured interviews with the 6 hospital educators involved in the project, as well as minutes of team meetings and the researcher's journal, were analyzed (the researcher was also a hospital educator on the team). Project management structure, educator support, and organizational pressures on the implementation project feature prominently in the case study. This study suggests that implementation of e-leaming will be more successful if (a) educators involved in the development of e-leaming curriculum are supported in their role as change agents, (b) the pain of vmleaming current educational practice is considered, (c) the limitations of the software being implemented are recognized, (d) time is spent leaming about best practice, and (e) the project is protected as much as possible from organizational pressures and distractions.

Study on the properties of piezoelectric materials and manganese-based oxide perovskites /

Perovskite type piezoelectric and manganese oxide materials have gained a lot of attention in the field of device engineering. Lead zirconium titananium oxide (PbZri.iTiiOa or PZT) is a piezoelectric material widely used as sensors and actuators. Miniaturization of PZTbased devices will not only perfect many existing products, but also opens doors to new applications. Lanthanum manganese oxides Lai-iAiMnOa (A-divalent alkaline earth such as Sr, Ca or Ba) have been intensively studied for their colossal magnetoresistance (CMR) properties that make them applicable in memory cells, magnetic and pressure sensors. In this study, we fabricate PZT and LSMO(LCMO) heterostructures on SrTiOa substrates and investigate their temperature dependency of resistivity and magnetization as a function of the thickness of LSMO(LCMO) layer. The microstructure of the samples is analysed through TEM. In another set of samples, we study the effect of application of an electric field across the PZT layer that acts as an external pressure on the manganite layer. This verifies the correlation of lattice distortion with transport and magnetic properties of the CMR materials.

Web based content and hybrid teaching: student perceptions of the effectiveness of using web based content and hyper-linked teaching units in teaching hybrid business and marketing post secondary classes /

This exploratory, descriptive action research study is based on a survey of a sample of convenience consisting of 172 college and university marketing students, and 5 professors who were experienced in teaching in an internet based environment. The students that were surveyed were studying e-commerce and international business in 3^^ and 4*'' year classes at a leading imiversity in Ontario and e-commerce in 5^ semester classes at a leading college. These classes were taught using a hybrid teaching style with the contribution of a large website that contained pertinent text and audio material. Hybrid teaching employs web based course materials (some in the form of Learning Objects) to deliver curriculimi material both during the attended lectures and also for students accessing the course web page outside of class hours. The survey was in the form on an online questionnaire. The research questions explored in this study were: 1. What factors influence the students' ability to access and learn from web based course content? 2. How likely are the students to use selected elements of internet based curriculum for learning academic content? 3. What is the preferred physical environment to facilitate learning in a hybrid environment? 4. How effective are selected teaching/learning strategies in a hybrid environment? The findings of this study suggest that students are very interested in being part of the learning process by contributing to a course web site. Specifically, students are interested in audio content being one of the formats of online course material, and have an interest in being part of the creation of small audio clips to be used in class.

The design, synthesis and characterization of new building blocks for the preparation of molecule-based magnetic materials /

Two new families of building blocks have been prepared and fully characterized and their coordination chemistry exploited for the preparation of molecule-based magnetic materials. The first class of compounds were prepared by exploiting the chemistry of 3,3'-diamino-2,2'-bipyridine together with 2-pyridine carbonyl chloride or 2-pyridine aldehyde. Two new ligands, 2,2'-bipyridine-3,3'-[2-pyridinecarboxamide] (Li, 2.3) and N'-6/s(2-pyridylmethyl) [2,2'bipyridine]-3,3'-diimine (L2, 2.7), were prepared and characterized. For ligand L4, two copper(II) coordination compounds were isolated with stoichiometrics [Cu2(Li)(hfac)2] (2.4) and [Cu(Li)Cl2] (2.5). The molecular structures of both complexes were determined by X-ray crystallography. In both complexes the ligand is in the dianionic form and coordinates the divalent Cu(II) ions via one amido and two pyridine nitrogen donor atoms. In (2.4), the coordination geometry around both Cu11 ions is best described as distorted trigonal bipyramidal where the remaining two coordination sites are satisfied by hfac counterions. In (2.5), both Cu(II) ions adopt a (4+1) distorted square pyramidal geometry. One copper forms a longer apical bond to an adjacent carbonyl oxygen atom, whereas the second copper is chelated to a neighboring Cu-Cl chloride ion to afford chloride bridged linear [Cu2(Li)Cl2]2 tetramers that run along the c-axis of the unit cell. The magnetic susceptibility data for (2.4) reveal the occurrence of weak antiferromagnetic interactions between the copper(II) ions. In contrast, variable temperature magnetic susceptibility measurements for (2.5) reveal more complex magnetic properties with the presence of ferromagnetic exchange between the central dimeric pair of copper atoms and weak antiferromagnetic exchange between the outer pairs of copper atoms. The Schiff-base bis-imine ligand (L2, 2.7) was found to be highly reactive; single crystals grown from dry methanol afforded compound (2.14) for which two methanol molecules had added across the imine double bond. The susceptibility of this ligand to nucleophilic attack at its imine functionality assisted via chelation to Lewis acidic metal ions adds an interesting dimension to its coordination chemistry. In this respect, a Co(II) quaterpyridine-type complex was prepared via a one-pot transformation of ligand L2 in the presence of a Lewis acidic metal salt. The rearranged complex was characterized by X-ray crystallography and a reaction mechanism for its formation has been proposed. Three additional rearranged complexes (2.13), (2.17) and (2.19) were also isolated when ligand (L2, 2.7) was reacted with transition metal ions. The molecular structures of all three complexes have been determined by X-ray crystallography. The second class of compounds that are reported in this thesis, are the two diacetyl pyridine derivatives, 4-pyridyl-2,6-diacetylpyridine (5.5) and 2,2'-6,6'-tetraacetyl-4,4'-bipyridine (5.15). Both of these compounds have been designed as intermediates for the metal templated assembly of a Schiff-base N3O2 macrocycle. From compound (5.15), a covalently tethered dimeric Mn(II) macrocyclic compound of general formula {[Mn^C^XJCl-FkO^Cl-lO.SFbO (5.16) was prepared and characterized. The X-ray analysis of (5.16) reveals that the two manganese ions assume a pentagonal-bipyramidal geometry with the macrocycle occupying the pentagonal plane and the axial positions being filled by a halide ion and a H2O molecule. Magnetic susceptibility data reveal the occurrence of antiferromagnetic interactions between covalently tethered Mn(II)-Mn(II) dimeric units. Following this methodology a Co(II) analogue (5.17) has also been prepared which is isostructural with (5.16).

A classroom-based investigation of reciprocal teaching at the grade seven level

This study assessed the effectiveness of a reciprocal teaching program as a method of teaching reading comprehension, using narrative text material in a t.ypical grade seven classroom. In order to determine the effectiveness of the reciprocal teaching program, this method was compared to two other reading instruction approaches that, unlike rcciprocal teaching, did not include social interaction components. Two intact grade scven classes, and a grade seven teacher, participated in this study. Students were appropriately assigned to three treatment groups by reading achievement level as determined from a norm-referenced test. Training proceeded for a five week intervention period during regularly scheduled English periods. Throughout the program curriculum-based tests were administered. These tests were designed to assess comprehension in two distinct ways; namely, character analysis components as they relate to narrative text, and strategy use components as they contribute to student understanding of narrative and expository text. Pre, post, and maintenance tests were administered to measure overall training effects. Moreover, during intervention, training probes were administered in the last period of each week to evaluate treatment group performance. AU curriculum-based tests were coded and comparisons of pre, post, maintenance tests and training probes were presented in graph form. Results showed that the reciprocal group achieved some improvement in reading comprehension scores in the strategy use component of the tests. No improvements were observed for the character analysis components of the curriculum-based tests and the norm-referenced tests. At pre and post intervention, interviews requiring students to respond to questions that addressed metacomprehension awareness of study strategies were administered. The intelviews were coded and comparisons were made between the two intelVicws. No significant improvements were observed regarding student awareness of ten identified study strategies . This study indicated that reciprocal teaching is a viable approach that can be utilized to help students acquire more effective comprehension strategies. However, the maximum utility of the technique when administered to a population of grade seven students performing at average to above average levels of reading achievement has yet to be determined. In order to explore this issue, the refinement of training materials and curriculum-based measurements need to be explored. As well, this study revealed that reciprocal teaching placed heavier demands on the classroom teacher when compared to other reading instruction methods. This may suggest that innovative and intensive teacher training techniques are required before it is feasible to use this method in the classroom.