Thermal Conductivity Measurements of Polyamide 12

An important component in understanding the laser sintering process is knowledge of the thermal properties of the processed material. Thermal conductivity measurements of pure polyamide 12 were conducted based on transient plane source technology using a Hot Disk® TPS500 conductivity measurement device. Polyamide samples were packed to three different densities in nitrogen at steady state. Thermal diffusivity and conductivity were measured from 40°C to 170°C for both fresh powder and previously heated (“recycled”) powder. The fresh powder tests revealed that thermal conductivity increased linearly with temperature while for previously heated powder, more constant and higher thermal conductivity was observed as it formed a powder cake. Tests were also performed on fully dense polyamide 12 to establish a baseline. Polyamide 12 powder had a room-temperature thermal conductivity of approximately 0.1 W/mK which increased with temperature, whereas the bulk laser sintered polyamide 12 room-temperature value was 0.26 W/mK and generally decreased with increasing temperature.Mechanical Engineerin

Peptide Drug Discovery: Innovative Technologies and Transformational Medicines

Interest in peptide drug discovery is surging. In the past several years,numerous pharmaceutical and biotech companies have committed considerable resources to peptide-based drug discovery. In part,this is being fueled by an increasing recognition that peptide drugs combine many of the virtues of small molecules and proteins, while minimizing several of their drawbacks, and that peptides can potentially expand the druggable space to include intracellular, extracellular and membrane associated protein–protein interactions. Moreover, powerful new in vitro and in silico technologies and breakthroughs in our understanding of natural peptides have emerged that provide peptide chemists with the toolsand insights they need to solve the various pharmacokinetic problems that often plague peptide drug discovery efforts. From stapled peptides,to highly versatile macrocyclic peptides and disulfide-rich peptides, to other peptides with various nonstandard chemistries, peptides are poised to fulfill their promise of providing a drug class that straddles the chemical space between small molecules and proteins, ultimately resulting in transformational medicines and improved clinical outcomes

Thermal Model of the Build Environment for Polyamide Powder Selective Laser Sintering

Precise thermal control of selective laser sintering (SLS) is desirable for improving geometric accuracy, mechanical properties, and surface finish of nylon, or polyamide (PA) parts. A modeling and measurement system was set up to facilitate development of thermal control strategies to improve these characteristics. A SinterStation 2500 SLS machine was used as a test machine for studying builds of parts made of DuraformTM PM nylon powder. Internal temperature measurements of the process were made using resistance temperature detectors (RTDs) embedded in the part bed powder. Surface temperature was measured with an infra-red camera aimed through the front window. A macro-scale time-dependent thermal numerical model of the build chamber and powder bins was developed as a means of evaluating temperature control of the build process. By comparing the measured and predicted temperature profiles, various estimates of the thermal diffusivity of the nylon powder were evaluated.Mechanical Engineerin

Poincaré series and holomorphic averaging

We provide an alternate proof of McMullen's theorem on contractive properties of the Poincaré series operator in the special case of the universal covering. This case includes in particular Kra's Theta Conjecture.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46577/1/222_2005_Article_BF01231321.pd

Beeinflusst die Trägerschaft der Regionalplanung die Inhalte der Regionalpläne und die regionale Siedlungsentwicklung? Theoretische Überlegungen und eine empirische Analyse für Deutschland

In diesem Beitrag geht es um die Frage, ob das Trägerschaftsmodell der Regionalplanung einen Einfluss einerseits auf die Regulierungsintensität der Regionalpläne, andererseits auf die regionale Siedlungsentwicklung hat. Dazu werden sieben Hypothesen formuliert. Auf der Grundlage einer bundesweit flächendeckenden Auswertung der Regionalpläne und Daten zur Siedlungsflächenentwicklung werden diese Hypothesen überprüft. Die vermuteten eindeutigen Zusammenhänge zwischen dem Zentralisierungsgrad der Trägerschaft und der Regulierungsintensität lassen sich nicht bestätigen. Für die weitere Forschung kann jedoch als Schlusshypothese festgehalten werden, dass die Wirkung der Regulierungsintensität auf die Flächeninanspruchnahme zwischen unterschiedlichen Trägerschaftsmodellen variiert. Für die Wirksamkeit des formellen raumordnerischen Instrumentariums sind insbesondere Umsetzungskompetenzen des Trägers entscheidend.This paper deals with the question of whether the responsible body of regional planning has an influence on the regulatory intensity of regional plans on the one hand and on regional settlement development on the other hand. Seven hypotheses are formulated for this purpose. Based on a nationwide evaluation of regional plans and data on settlement development in Germany, these hypotheses are tested. The presumed clear correlations between the degree of centralization of responsible bodies and the regulatory intensity cannot be confirmed. However, a final hypothesis for further research can be stated. The effect of regulatory intensity on land take varies between different responsible bodies. The effectiveness of the formal spatial planning instruments depends on the implementation competencies of the responsible body

Die Entwicklung der Regulierungsintensität der deutschen Regionalpläne von 1985 bis 2017: Ein empirischer Beitrag zur Diskussion um den Bedeutungsverlust der Raumordnung

Als ein Beitrag in der Debatte um Deregulierung der Raumordnung und schlanke Regionalpläne wird mit dem vorliegenden Beitrag die erste Langzeituntersuchung für Deutschland vorgelegt, in dem die Regulierungsintensität aller im Jahr 2017 rechtsgültigen Regionalpläne zu den Themen Siedlungs- und Freiraumentwicklung im Zeitverlauf untersucht wurde. Im Ergebnis kann die Vermutung einer generellen Deregulierung und Verschlankung der Regionalpläne nicht belegt werden. Im Gegenteil führten Veränderungen in den gesetzlichen Grundlagen wie der Vorrang der Innen- vor der Außenentwicklung dazu, dass vor allem bei den positivplanerischen Instrumenten mit einer aktiven Rolle der Regionalplanung die Regulierungsintensität eher kontinuierlich zugenommen hat. Gleichwohl lassen sich in einigen Bundesländern Verschlankungstendenzen nachweisen, die zum Teil als Deregulierungstendenzen interpretiert werden können. Zumindest bislang sind sie jedoch lediglich Ausdruck landesspezifischer Wege zur Ausgestaltung der Raumordnung und keine Anzeichen eines beschleunigten Deregulierungswettbewerbs.As a contribution to the debate on deregulation of spatial planning and lean regional plans, this paper presents the first long-term study for Germany analysing the regulatory intensity of all regional plans legally valid in 2017 on the topics of settlement and open space development over time. As a final result, the assumption of a general deregulation and streamlining of regional plans cannot be confirmed. In contrast, changes in the legal basis, such as the priority of inner over outer urban development, have led to a continuous increase in the regulatory intensity over time, particularly in the case of positive growth management policies with an active role of regional planning. At the same time, there is evidence of streamlining tendencies in some states, which can partly be interpreted as deregulation tendencies. To date, however, they are merely an expression of state-specific ways of shaping regional planning and not a sign of an accelerated deregulation competition

Regionales Flächenmanagement in den deutschen Metropolregionen

Metropolregionen sind das Ergebnis von räumlichen Reskalierungsprozessen und Regionsbildungen und gelten als "soft spaces of governance", bezugnehmend auf die internationalen Debatten um den "new regionalism". Dieser Beitrag setzt an kritischen Aussagen an, wonach die Fokussierung der Raumentwicklungspolitik auf die wettbewerbsorientierten Metropolregionen von klassischen raumordnerischen Aufgaben ablenke. Hierzu werden die institutionelle Integration der Regionalplanung in die Metropolregionen und die Aktivität des regionalen Flächenmanagements sowie die Regulierungsintensität der Regionalpläne im Rahmen eines Vergleichs unterschiedlicher Gruppen von Metropolregionen untersucht und diskutiert. Im Ergebnis lässt sich die These einer institutionell fragmentierten ordnungspolitischen Steuerung der Siedlungsentwicklung durch die Regionalplanung nur für einige Metropolregionen aufrechterhalten, bei denen es auch im Regionskern keine dafür relevanten Institutionen und Instrumente gibt. Was die 'weichen' Instrumente des regionalen Flächenmanagements angeht, stellt sich die Situation sehr unterschiedlich dar. Hier werden die Handlungspotenziale auch in Metropolregionen mit starken institutionellen Kernen noch nicht voll ausgeschöpft.Metropolitan regions result from spatial rescaling processes and region formations and are considered as "soft spaces of governance", referring to international debates on the "new regionalism". This paper addresses the criticism that the focus on competitive metropolitan regions distracts from the need for action on classic spatial planning issues. For this, the paper examines and discusses the institutional integration of regional planning in the German metropolitan regions and the activities of regional growth management as well as the regulatory intensity of regional plans based on a group comparison of metropolitan regions. As a result, the thesis of an institutionally fragmented regulatory growth management by regional planning can only be confirmed for a few metropolitan regions, where no relevant institutions and instruments are implemented in the core area. Regarding the "soft" instruments of growth management, the situation is very different. Here, the action potential is not yet fully utilized, even in metropolitan regions with strong institutional cores

Breast cancer detection among young survivors of pediatric Hodgkin lymphoma with screening magnetic resonance imaging

BACKGROUND Female survivors of pediatric Hodgkin lymphoma (HL) who have received chest radiotherapy are at increased risk of breast cancer. Guidelines for early breast cancer screening among these survivors are based on little data regarding clinical outcomes. This study reports outcomes of breast cancer screening with MRI and mammography (MMG) after childhood HL. METHODS We evaluated the results of breast MRI and MMG screening among 96 female survivors of childhood HL treated with chest radiotherapy. Outcomes measured included imaging sensitivity and specificity, breast cancer characteristics, and incidence of additional imaging and breast biopsy. RESULTS Median age at first screening was 30 years, and the median number of MRI screening rounds was 3. Ten breast cancers were detected in 9 women at a median age of 39 years (range, 24-43 years). Half were invasive and half were preinvasive. The median size of invasive tumors was 8 mm (range, 3-15 mm), and none had lymph node involvement. Sensitivity and specificity of the screening modalities were as follows: for MRI alone, 80% and 93.5%, respectively; MMG alone, 70% and 95%, respectively; both modalities combined, 100% and 88.6%, respectively. All invasive tumors were detected by MRI. Additional investigations were required in 52 patients, (54%), and 26 patients (27%) required breast biopsy, with 10 patients requiring more than 1 biopsy. CONCLUSIONS Screening including breast MRI with MMG has high sensitivity and specificity in pediatric HL survivors, with breast cancers detected at an early stage, although it is associated with a substantial rate of additional investigations. Cancer 2014;120:2507–2513. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. Screening female survivors of pediatric Hodgkin Lymphoma for breast cancer with MRI and mammography detected tumors at an earlier stage than prior studies of mammography alone, although a substantial proportion of women required additional tests for benign imaging findings. The 5-year cumulative incidence of invasive or preinvasive tumors after initiating screening was 10.8%