During the second half of the 20th century, there was an epic deterioration of the urban fabric of the typical American neighborhood. Starting with the fleeing of city dwellers into the outskirts of suburbia in the 1950s and the exodus of commercial institutions in the 1970s, neighborhood sprawl hit its stride with the elimination of the neighborhood school in the 1980s. With this community-defining component being replaced by giant, remote educational facilities, the American neighborhood was finally a shell of its former self. If the neighborhood represents the cell, then the home represents the nucleus. In 2003, 1.1 million children were being homeschooled in America, with signs of homeschooling becoming a growing trend. One of the main reasons parents chose to homeschool their children was concern about the environment of other schools. With a large number of students being sent to mega-schools and a growing number of students being homeschooled, there is an increasing gap between the scales of schools being used for education, and neither seems to be a complete solution. In addition, a significant part of relevant literacy in today?s global community deals with digital literacy. The digital divide is the gap between those people with effective access to digital and information technology, and those without. Many institutions including the United Nations believe the digital divide is the key to local and global, social and economic inequalities. Information, or knowledge, is being stored and made accessible through digital means. However, if a person does not know how to access this information, they are less equipped than the person who does, and the problem of a gap in knowledge becomes exponentially larger. In what ways can low population learning environments be networked into the urban fabric of a blighted neighborhood for the purpose of improving academic performance? In addition, what are the social, civic and economic opportunities and disadvantages afforded to a neighborhood when a digital learning network is overlaid with a physical network of learning environments? This thesis intends to reestablish the neighborhood school, by injecting contemporary, low-population learning environments branded as HOM-S to act as a brand of modular architecture which will bridge the gap between the home and the school. The solution is proposed as potentially ubiquitous, but for the sake of this thesis I will be using the neighborhoods surrounding Holmes Elementary School and Liberty City Elementary School in Miami, Fl, as its site. This neighborhood has a high crime rate, low testing scores, high dropout rate, lack of positive identity, and low economic class, and therefore represents the extreme conditions this thesis is poised to remediate. The program will be defined as a pre-university learning environment that is meant to complement and correct at-risk education systems and the neighborhoods they serve. The HOM-S will be a bridge between the home and the mega-school, creating both an ?education path? and a campus network for pre-university students. Through the use of flexible technology, distance learning networks, and site sensitive architecture, as well as a re-interpretation of curriculum and teacher-student roles, these environments will be designed to turn deteriorated neighborhoods into healthy communities.

This work describes the realization of physically crosslinked networks based on gelatin by the introduction of functional groups enabling specific supramolecular interactions. Molecular models were developed in order to predict the material properties and permit to establish a knowledge-based approach to material design. The effect of additional supramolecular interactions with hydroxyapaptite was then studied in composite materials. The calculated properties are compared to experimental results to validate the models. The models are then further used for the study of physically crosslinked networks. Gelatin was functionalized with desaminotyrosine (DAT) and desaminotyrosyl-tyrosine (DATT) side groups, derived from the natural amino acid tyrosine. These group can potentially undergo to π-π and hydrogen bonding interactions also under physiological conditions. Molecular dynamics (MD) simulations were performed on models with 0.8 wt.-% or 25 wt.-% water content, using the second generation forcefield CFF91. The validation of the models was obtained by the comparison with specific experimental data such as, density, peptide conformational angles and X-ray scattering spectra. The models were then used to predict the supramolecular organization of the polymer chain, analyze the formation of physical netpoints and calculate the mechanical properties. An important finding of simulation was that with the increase of aromatic groups also the number of observed physical netpoints increased. The number of relatively stable physical netpoints, on average zero 0 for natural gelatin, increased to 1 and 6 for DAT and DATT functionalized gelatins respectively. A comparison with the Flory-Rehner model suggested reduced equilibrium swelling by factor 6 of the DATT-functionalized materials in water. The functionalized gelatins could be synthesized by chemoselective coupling of the free carboxylic acid groups of DAT and DATT to the free amino groups of gelatin. At 25 wt.-% water content, the simulated and experimentally determined elastic mechanical properties (e.g. Young Modulus) were both in the order of GPa and were not influenced by the degree of aromatic modification. The experimental equilibrium degree of swelling in water decreased with increasing the number of inserted aromatic functions (from 2800 vol.-% for pure gelatin to 300 vol.-% for the DATT modified gelatin), at the same time, Young’s modulus, elongation at break, and maximum tensile strength increased. It could be show that the functionalization with DAT and DATT influences the chain organization of gelatin based materials together with a controlled drying condition. Functionalization with DAT and DATT lead to a drastic reduction of helical renaturation, that could be more finely controlled by the applied drying conditions. The properties of the materials could then be influenced by application of two independent methods. Composite materials of DAT and DATT functionalized gelatins with hydroxyapatite (HAp) show a drastic reduction of swelling degree. In tensile tests and rheological measurements, the composites equilibrated in water had increased Young’s moduli (from 200 kPa up to 2 MPa) and tensile strength (from 57 kPa up to 1.1 MPa) compared to the natural polymer matrix without affecting the elongation at break. Furthermore, an increased thermal stability from 40 °C to 85 °C of the networks could be demonstrated. The differences of the behaviour of the functionalized gelatins to pure gelatin as matrix suggested an additional stabilizing bond between the incorporated aromatic groups to the hydroxyapatite. / Diese Arbeit beschreibt die Entwicklung von durch spezifische physikalische Wechselwirkungen quervernetzten Gelatine-basierten Materialien. Dazu wurden zunächst Computermodelle entwickelt, mit denen Eigenschaften der Materialien vorhergesagt werden sollten, um so eine wissensbasierte Entwicklung zu ermöglichen, um dann die Ergebnisse mit experimentellen Daten zu vergleichen und die Materialien und Modelle als Grundlage für weitere Entwicklungen zu nutzen. Gelatine wurde mit Desaminotyrosin (DAT) und Desaminotyrosyltyrosin (DATT) funktionalisiert, die sich von der natürlichen Aminosäure Tyrosin ableiten. Diese Gruppen können potentiell π-π Wechselwirkungen und Wasserstoffbrückenbindungen auch unter physiologischen Bedingungen eingehen. Es wurden Computersimulationen der Materialien mittels Moleküldynamik durchgeführt, wobei Modelle mit 0.8 Gew.-% und 25 Gew.-% Wassergehalt betrachtet wurden. Die Validierung der Modelle erfolgte durch Vergleich der errechneten mit experimentellen Daten wie z.B. der Dichte, Bindungswinkeln sowie Röntgenstreuungsspektren. Die Modelle wurden dann zur Vorhersage der molekularen Organisation der Polymerketten, Formierung physikalischer Netzpunkte und Berechnung der mechanischen Eigenschaften eingesetzt. Die Funktionalisierung der Gelatine mit DAT bzw. DATT führten wie gewünscht zur Ausbildung physikalischer Netzpunkte durch π-π Wechselwirkungen und Wasserstoffbrücken¬bindungen. Ein Schlüsselergebnis der Simulationen war, dass mit zunehmender Zahl an aromatischen Gruppen auch eine Zunahme der physikalischen Netzpunkte beobachtet werden konnte. Die funktionalisierten Gelatinen konnten durch chemoselektive Reaktion der Aminogruppen der Gelatine mit den freien Carboxylgruppen von DAT und DATT hergestellt werden. Materialien mit 25 Gew.-% Wassergehalt hatten in der Simulation und im Experiment mechanische Eigenschaften derselben Größenordnung (z.B. E-Moduln im unteren GPa-Bereich). Der Quellungsgrad der Materialien im Experiment nahm mit zunehmender Zahl an aromatische Gruppen ab (von 2800 Vol.-% auf 300 Vol.-%), wobei der Elastizitätsmodul, die Bruchdehnung sowie die Zugfestigkeit zunahmen. Die Funktionalisierung der Gelatine ist eine chemische Methode, um die Kettenanordnung auf molekularer Ebene zu beeinflussen, während die genaue Kontrolle der Trocknungs¬bedinguungen von Gelatine-basierten Materialien eine physikalische Methode mit demselben Ziel ist. Es konnte gezeigt werden, dass die Funktionalisierung von Gelatine mit DAT oder DATT zu einer stark verminderten Helixausbildungstendenz, die jedoch durch Variation der Trocknunsgbedingungen noch fein abgestimmt werden konnte. Somit konnten die mechanischen Eigenschaften von Filmen aus funktionlisierter Gelatine mit zwei unabhängigen Methoden eingestellt werden. Komposite der mit DAT oder DATT funktionalisierten Gelatine und Hydroxyapatit (HAp) zeigten deutlich verringerter Quellung. In Zugdehnungsexperimenten und rheologischen Untersuchungen zeigten die Komposite im Gleichgewichtsquellungszustand erhöhte Elastizitätsmoduln (von 200 kPa auf bis zu 2 MPa) und Zugfestigkeit (von 57 kPa auf bis zu 1.1 MPa). Darüber hinaus konnte die Übergangstemperatur Tc deutlich gesteigert werden (von ca. 40 °C auf > 85 °C). Dieses Verhalten ließ sich auf stabilisierende Bindungen zwischen den aromatische Gruppen und dem HAp zurückführen.

Human body temperature is an important indicator of physical performance and condition in terms of comfort, heat or cold stress. The aim of this research was to develop Temperature Sensing Fabric (TSF) for continuous temperature measurement in healthcare applications. The study covers the development and manufacture of TSF by embedding fine metallic wire into the structure of textile material using a commercial computerised knitting machine. The operational principle of TSF is based on the inherent propensity of a metal wire to respond to changes in temperature with variation in its electrical resistance. Over 60 TSF samples were developed with combinations of different sensing elements, two inlay densities and highly textured polyester yarn as the base material. TSF samples were created using either bare or insulated wires with a range of diameters from 50 to 150 μm and metal wires of nickel, copper, tungsten, and nickel coated copper. In order to investigate the Temperature-Resistance (T-R) relationship of TSF samples for calibration purposes, a customised test rig was developed and monitoring software was created in the LabVIEW environment, to record the temperature and resistance signals simultaneously. TSF samples were tested in various thermal environments, under laboratory conditions and in practical wear trials, to analyse the relationship between the temperature and resistance of the sensing fabric and to develop base line specifications such as sensitivity, resistance ratio, precision, nominal resistance, and response time; the influence of external parameters such as humidity and strain were also monitored. The regression uncertainty was found to be less than in ±0.1°C; the repeatability uncertainty was found to be less than ±0.5°C; the manufacturing uncertainty in terms of nominal resistance was found to be ± 2% from its mean. The experimental T-R relationship of TSF was validated by modelling in the thermo-electrical domain in both steady and transient states. A maximum error of 0.2°C was found between the experimental and modelled T-R relationships. TSF samples made with bare wire sensing elements showed slight variations in their resistance during strain tests, however, samples made with insulated sensing elements did not demonstrate any detectable strain-dependent-resistance error. The overall thermal response of TSF was found to be affected by basal fabric thickness and mass; the effect of RH was not found to be significant. TSF samples with higher-resistance sensing elements performed better than lower-resistance types. Furthermore, TSF samples made using insulated wire were more straightforward to manufacture because of their increased tensile strength and exhibited better sensing performance than samples made with bare wire. In all the human body wear trials, under steady-state and dynamic conditions both sensors followed the same trends and exhibited similar movement artifacts. When layers of clothing were worn over the sensors, the difference between the response of the TSF and a high-precision reference temperature were reduced by the improved isothermal conditions near the measurement site.