archives@tulane.edu / As global energy consumption continues to grow, new paths towards renewable energy generation are needed to reduce environmental impact and allow for more zero-net energy development. This includes not only electricity generation but also energy required for thermal applications. This dissertation explores three different technologies to generate electricity and high temperature heat simultaneously by using an actively tracked parabolic dish concentrator (2.72 m2) and an all-in-one hybrid receiver. This hybrid receiver usually consists of two key components, a PV module assembled with multijunction solar cells based on III-V materials, and a thermal receiver that transfers absorbed solar energy into a working fluid for a variety of commercial and industrial process heating applications. A key goal of this work is to use spectrum splitting and other design innovations to operate PV cells at much lower temperatures than the thermal receiver output temperatures. PV cooling is critical for PV modules to sustain high energy conversion efficiencies and to work for longer duration under concentrated light. A key distinction in different designs reported here is how the PV cells are cooled, either “transmissive microfluidic cooling”, “transmissive direct fluid cooling”, and “non-transmissive microfluidic cooling”. All three technologies show good performance for both efficient PV cooling (< 120°C) and high system energy conversion efficiency (> 80%). This dissertation is divided into four key chapters. Chapter 2 discusses spectrum splitting CPV with transmissive microfluidic cooling, focusing on the optical performance of the PV modules. By applying a transfer matrix-style approach, the cumulative transmission through the entire PV module is calculated: these results are verified experimentally. By doing so, the power collected by the PV cells and thermal receiver can be predicted. Chapter 3 explores a spectrum splitting hybrid receiver design using a cheaper and more straightforward cooling method that flows silicone oil across PV cells to extract their waste heat and to eliminate the use of sapphire for cost reduction. The cooling performance is verified by outdoor tests and the system efficiencies are discussed under different solar concentration. Chapter 4 investigates another hybrid receiver design that utilizes waste heat from high efficiency PV cells to preheat the working fluid in the thermal receiver instead of dumping the energy to surroundings as in the previous two methods. This design allows both the cells and the thermal receiver to be illuminated with concentrated sunlight simultaneously without the need for spectrum splitting. The electrical and thermal performance are tested both in the lab and outdoors. Chapter 5 discusses a proposed way to enhance the transmission of the spectrum splitting III-V solar cells used in Chapters 2 and 3. Epitaxial lift-off is used to remove the III-V cell substrate and to fabricate highly infrared-transmissive, spectrum-splitting thin-film solar cells. In summary, we explore the power collection performance, including optical, electrical, and thermal aspects, for these hybrid solar receiver technologies, enabling their use in a number of promising applications. / 1 / Yaping Ji

Monitoring stress in real-time, in a non-laboratory environment can be benecial in several applications. One of these, which have been the motivation for this thesis, is to to perform this measurement during Attention decit hyperactivity disorder (ADHD) diagnosis. Monitoring several physiological responses to internal or external stimuli in a single soft-real-time system is nota solution widely used in an application like this. The thesis starts by studying several stress related responses in detail. Sensors for all of the responses are not implemented nor is it possible toimplement in to the desired system. After the study is was decided to implement two measurement modules. The first a Photo-plethysmogrophy (PPG) measurement module to measure heart rate and also estimate breathing. This module is prepared for estimating arterial blood oxygen levels but the calculation or verification have not been done. The second is Skin Conductance (SC) measurement module and in to both ofthese add a temperature sensor to measure the temperature of the skin. Time constraints limit the SC module to only be presented in theory. The PPG module on the other hand have been realisedin a prototype. This prototype performs the measurement in transmissive mode on the left earlobe, which leaves the hands free and it does not affect the hearing on that ear. The prototype giveout acceptable signal quality when good contact with the measurement site is achieved. The signalinterpretation, such as performing the signal analysis to count the beats per minute, is outside thescope of this thesis and will therefore not be presented but the signals can be seen in figures. / Att mäta stress i realtid i verkliga situationer kan vara fördelaktigt för flera applikationer. Det som har legat som grund för denna uppsats är att kunna mäta stress under ADHD diagnostisering. Genom att kombinera de vanliga testerna med stressnivåer hos patienten hoppas man kunna utveckla nya metoder för diagnostisering. Att mäta fera parametrar samtidigt i realtid är inte något ofta utförs idag. För att komma igång har fera kroppsliga funktioner som påverkas på olika sätt av stress studerats. Alla dessa funktioner kan inte inkluderas i det system som önskas konstrueras antingen på grund av systemets karaktär eller på grund tidsbrist. Efter att undersökningen var klar beslutades det att konstruera två moduler. Den första använder en mätteknik som kallas PPG och används för att mäta hjärtfrekvens, även andningsfrekvensen estimeras och modulen är förberedd för att estimera blodsyre nivåa men signalbehandling och validering för detta är inte gjord. Den andra modulen mäter resistans i huden. I dessa moduler lades även till en temperatur sensor för att mäta hudtemperaturen. Tidsbrist har gjort att endast en av dem två modulerna kunnat realiserats. Den som realiserat är PPG modulen och modulen för hudresistans presenteras endast teoretiskt. PPG modulen genomför matningen med en transmissiv teknik på vänster öra och ger ut en acceptabel signal kvalité om sensorn får bra kontakt. Arbetet är avgränsat och inkluderar inte signalanalysen av signalen däremot visualiseras signalen i figurer.

Medková, E. (2012): Constructivism in geography education. Department of Social Geography and Regional Development, Charles University in Prague. The thesis deals with a constructivist model used in Geography classes. The theoretical part focuses on the characteristic of this model and compares it with the traditional transmissive model. It describes the methods used in the constructivist teaching. Part of the practical section was the pedagogical experiment that compared the efficiency of constructivist and transmissive teaching. Experiment was realized in the Primary school in two parallel 7th grade classes. There were two geographical topics tought - monsoons and the development of the Asian states. The development of the Asian states topic was tought transmissively in one class and in a constructivist manner in the second class. As a second step the other topic of monsoons was tought and the teaching method in the classes was interchanged. The efficiency of the teaching was determined by the help of the didactic test and then statistically evaluated.

<p>&nbsp / Characterisation of fractured rock aquifers is important when dealing with groundwater protection and management. Fractures are often good conduits for water and contaminants, leading to high flow velocities and the fast spread of contaminants in these aquifers. A cost effective methodology is required for the characterisation of the role of individual fractures contributing to flow to boreholes in fractured rock aquifers. Literature shows that some of the conventional methods used to characterise hydraulic properties in fractured rock aquifers are expensive, complicated, time consuming and are associated with some disadvantages such as over-or under- estimations of flow rates. iii This thesis evaluates the use of Fluid Electrical Conductivity (FEC) logging in fractured rock aquifers. This FEC data are compared to various traditional methods used to determine aquifer hydraulic properties applied at the Franschhoek and Rawsonville research sites. Both these sites were drilled into the fractured rock Table Mountain Group (TMG) Aquifer, forming one of the major aquifers in South Africa.</p>

<p>&nbsp / Characterisation of fractured rock aquifers is important when dealing with groundwater protection and management. Fractures are often good conduits for water and contaminants, leading to high flow velocities and the fast spread of contaminants in these aquifers. A cost effective methodology is required for the characterisation of the role of individual fractures contributing to flow to boreholes in fractured rock aquifers. Literature shows that some of the conventional methods used to characterise hydraulic properties in fractured rock aquifers are expensive, complicated, time consuming and are associated with some disadvantages such as over-or under- estimations of flow rates. iii This thesis evaluates the use of Fluid Electrical Conductivity (FEC) logging in fractured rock aquifers. This FEC data are compared to various traditional methods used to determine aquifer hydraulic properties applied at the Franschhoek and Rawsonville research sites. Both these sites were drilled into the fractured rock Table Mountain Group (TMG) Aquifer, forming one of the major aquifers in South Africa.</p>

Magister Scientiae - MSc / Characterisation of fractured rock aquifers is important when dealing with groundwater protection and management. Fractures are often good conduits for water and contaminants, leading to high flow velocities and the fast spread of contaminants in these aquifers. A cost effective methodology is required for the characterisation of the role of individual fractures contributing to flow to boreholes in fractured rock aquifers. Literature shows that some of the conventional methods used to characterise hydraulic properties in fractured rock aquifers are expensive, complicated, time consuming and are associated with some disadvantages such as over-or under- estimations of flow rates. This thesis evaluates the use of Fluid Electrical Conductivity (FEC) logging in fractured rock aquifers. This FEC data are compared to various traditional methods used to determine aquifer hydraulic properties applied at the Franschhoek and Rawsonville research sites. Both these sites were drilled into the fractured rock Table Mountain Group (TMG) Aquifer, forming one of the major aquifers in South Africa. / South Africa

Ways for self development of teaching strategy Abstract: The aim of this thesis is to analyse the diagnostic tools designed by M. Hejny and his team. These tools focus on teaching styles in education, observing the personal development of a mathematics intern teacher. The study materials i have obtained during my practice are used to describe and analyse the teacher's educational style, with the use of twenty defining parameters. My thesis is based on Gabriela Hlavata's master thesis, a teacher who describes her own shift from transmissible to constructive teaching in mathematics classes. Hlavata depicts this shift clearly, hence the reason I have decided to describe it with a set of parameters measuring the intern teacher's educational style. The subsequent aim is to trace my own evolution in teaching mathematics. Practice and materials gained in my graduation, together with the twenty educational parameters as outlined in my thesis, will serve to analyse and describe my own educational style. In choosing this topic, I am trying to answer the following question; whether the observation of a teacher's educational style will impact on the delivery and quality of mathematics lessons? Furthermore, is improvement possible, or have I reached the capacity of my own teaching ability? Additionally this thesis...

In this research, the teaching styles of one biology teacher in each of three high schools in Rwanda are investigated. The purpose of the research is to find out how the adopted biology teaching styles impact on the teacher-student interaction and on the student‟s learning of biology in Kigali City in Rwanda. This research is descriptive and it is conducted in the qualitative research paradigm. The research approach used is a case study in three state and subsidised high schools. The research methods included interviews with six students and three teachers, classroom observations of three biology lessons per teacher and field-notes. The Rwandan education system has introduced a new approach to teaching i.e. the learner-centred pedagogy through an associative teaching style. In high schools, this new approach was first implemented in the school year 2011 but this implementation has been constrained by the scarcity of resources. Furthermore, some biology teachers, at the start of 2011, were not yet informed by educational authorities about the implementation of the learner-centred pedagogy. Thus, this research shows that some biology teachers are still using the teacher-centred approach; this is the case for Mr. Odumbe, whose teaching style is dominated by the transmissive approach, or the case of Mr. Kaggwa, whose view is that the educational authorities encourage the transmissive method of teaching. Even though the learner-centred pedagogy is encouraged because it fosters lasting knowledge and easy application of knowledge acquired in everyday life, the group work approach to teaching has been poorly managed and did not achieve desired results where it was used during this research. The participating biology students and teachers see the learner-centred pedagogy as slowing down the progression of teaching the content matter while the national examination covers the whole curriculum content. Therefore, although teachers were using different teaching approaches, once they are asked which approach they can choose to use, both students and teachers prefer to continue to use the teacher-centred approach in order to meet the content outcomes required in the national examination. Another result was that all participating students found their teachers supportive and nurturing and research is encouraged by all teachers regardless of their dominating teaching styles.

Tato dizertace je zaměřena na medicínskou zobrazovací modalitu – ultrazvukovou počítačovou tomografii – a algoritmy zlepšující kvalitu zobrazení, zejména kalibraci USCT přístroje. USCT je novou modalitou kombinující ultrazvukový přenos signálů a principy tomografické rekonstrukce obrazů vyvíjených pro jiné tomografické systémy. V principu lze vytvořit kvantitativní 3D obrazové objemy s vysokým rozlišením a kontrastem. USCT je primárně určeno pro diagnózu rakoviny prsu. Autor spolupracoval na projektu Institutu Zpracování dat a Elektroniky, Forschungszentrum Karlsruhe, kde je USCT systém vyvíjen. Jeden ze zásadních problémů prototypu USCT v Karlsruhe byla absence kalibrace. Tisíce ultrazvukových měničů se liší v citlivosti, směrovosti a frekvenční odezvě. Tyto parametry jsou navíc proměnné v čase. Další a mnohem závažnější problém byl v pozičních odchylkách jednotlivých měničů. Všechny tyto aspekty mají vliv na konečnou kvalitu rekonstruovaných obrazů. Problém kalibrace si autor zvolil jako hlavní téma dizertace. Tato dizertace popisuje nové metody v oblastech rekonstrukce útlumových obrazů, kalibrace citlivosti měničů a zejména geometrická kalibrace pozic měničů. Tyto metody byly implementovány a otestovány na reálných datech pocházejících z prototypu USCT z Karlsruhe.

The diploma thesis is focused on the issue of word problems with different results, to which is not given systematic attention in the specialized literature. The focus of the work is to observe how pupils and teachers of elementary school work with a word problem with different results. The theoretical part focuses on the typology of word problems, the phases of their solution and solving strategies. Furthermore, the classification of word problems according to the number of results and the typology of word problems with different results is proposed. A significant part consists of the goals with which this type of task can be assigned in the teaching of mathematics and which change depending on the teacher and his approach to teaching. The work also deals with the basic characteristics of teaching styles. The selected qualitative research using the method of observation and questionnaire allows to describe the work of teachers with a word problem with different results and to identify elements of teaching styles, namely transmissive and constructivist approaches, which are reflected in the actions of teachers. An additional method is the analysis of selected textbooks in terms of the presence of word problems with different results, which reveals whether such tasks occur in textbooks and what...