Sub-millimeter Tests of the Gravitational Inverse-square Law

Motivated by a variety of theories that predict new effects, we tested the gravitational 1/r^2 law at separations between 10.77 mm and 137 microns using two different 10-fold azimuthally symmetric torsion pendulums and rotating 10-fold symmetric attractors. Our work improves upon other experiments by up to a factor of about 100. We found no deviation from Newtonian physics at the 95% confidence level and interpret these results as constraints on extensions of the Standard Model that predict Yukawa or power-law forces. We set a constraint on the largest single extra dimension (assuming toroidal compactification and that one extra dimension is significantly larger than all the others) of R <= 160 microns, and on two equal-sized large extra dimensions of R <= 130 microns. Yukawa interactions with |alpha| >= 1 are ruled out at 95% confidence for lambda >= 197 microns. Extra-dimensions scenarios stabilized by radions are restricted to unification masses M >= 3.0 TeV/c^2, regardless of the number of large extra dimensions. We also provide new constraints on power-law potentials V(r)\propto r^{-k} with k between 2 and 5 and on the gamma_5 couplings of pseudoscalars with m <= 10 meV/c^2.Comment: 34 pages, 38 figure

Anatomical flow phantoms of the nonplanar carotid bifurcation, Part II: experimental validation with Doppler ultrasound

A nonplanar wall-less anatomical flow phantom of a healthy human carotid artery is described, the construction of which is based on a lost-core technique described in the companion paper (Part I) by Watts et al. (2006). The core was made by rapid prototyping of an idealized three-dimensional computer model of the carotid artery. Flow phantoms were built using these idealized non planar carotid artery bifurcations. Physiologically realistic flow waveforms were produced with resistance index values of 0.75, 0.72 and 0.63 in the common, external and internal carotid artery branches, respectively. Distension of the common carotid using M-mode imaging was found to be at 10% of diameter. Although differences in vessel diameter between the phantom and that of the original computer model were statistically significant (p 0.05) in measurements made on the lost-cores and those obtained by B-mode ultrasound on the resulting flow phantoms. In conclusion, it was possible to reliably reproduce geometrically similar anatomical flow phantoms that are capable of producing realistic physiological flow patterns and distensions

Comparison of Brachial Artery Pressure and Derived Central Pressure in the Measurement of Abdominal Aortic Aneurysm Distensibility

AbstractObjective AAA distensibility (Ep, β) may predict growth and risk of rupture. However, distensibility measurements based on brachial rather than central pressure may be inaccurate. Our aim was to compare AAA distensibility using non-invasive brachial and derived central aortic pressure. Design brachial and central pressures were measured prospectively by automated sphygmomanometry (Omron) and pulse wave analysis (SphygmoCor) respectively. AAA distensibility was calculated using brachial (Epb, βb) and central (Epc, βc) pressures by ultrasonic echo-tracking (Diamove). Twenty-eight patients (18 males) were selected on a first come basis from a larger study of AAA patients. There were no exclusion criteria, so 54% had cardiac dysfunction (MI, angina) and 14% were hypertensive (BP>140/90 mmHg). Results median (IQR) age was 74 (70–77) years, median AAA (IQR) diameter was 44 (40–51) mm. Central and brachial systolic pressures were significantly different, [140 (121–153) vs 144 (130–164) mmHg respectively, p≤0.01]. Central and brachial diastolic pressures were not significantly different [76 (72–86) vs 76 (71–86) mmHg respectively, p=0.5]. Epc(3.0, [2.2–4.9]) and βc(22.2 [15.5–33.2]) were significantly lower than Epb(3.6, [2.4–5.1] 105Nm−2) and βb(24.7 [17.1–33.0] a.uall p<0.001. Brachial and central derived distensibility remained significantly different after adjusting for age and diameter (p<0.001). Conclusion the use of brachial pressure leads to a small, systematic overestimate of Ep (18%) and β (11%) independent of age and AAA diameter. This systematic error will not bias follow-up of changes in distensibility

Sähkötilojen kuntokartoitus

Opinnäytetyö käsittelee Tampereen Energiantuotanto Oy:n Pirkanmaan alueella sijaitsevien kiinteiden lämpökeskusten sähkötilojen ja muun valitun sähkölaitteiston kuntokartoitusta ja parannusehdotusten kustannusarviota. Työn tavoitteena oli kerätä tiivis tietopaketti lämpökeskusten sähkölaitteiston kunnosta ja tehdä parannusehdotuksista kustannusarviot päätöksenteon tueksi. Tavoitteisiin pyrittiin tutustumalla voimassa oleviin standardeihin, turvallisuusmääräyksiin ja tarkastuskäytäntöihin sekä laatimalla tarkastuspöytäkirja. Tarkastuspöytäkirjojen pohjalta tehtiin yhteenvedot ja sähkölaitteiston parannusehdotukset. Parannusehdotusten kustannusarviot koottiin käyttämällä tuotteiden listahintoja ja tilaajan varastohenkilökunnalta ja asiantuntijoilta saatuja tietoja. Tarkastettu sähkölaitteisto oli laaja ja asennettu viidellä eri vuosikymmenellä. Laitteistossa oli hyvä-, tyydyttävä- ja välttäväkuntoisia laitteita. Yhtään huonokuntoista laitteistoa, jolla olisi välitön uusimis- tai korjaustarve, ei löytynyt. Kustannusarviot olivat n. 100–50 000 €. Suurin osa kustannusarvioiden summista oli minimaalisia, muutamia satoja euroa. Kustannusarvioiden suurimmat summat olivat Julkujärven ja Hervannan lämpökeskuksien parannusehdotuksilla. Johtopäätöksenä todettiin, että sähkölaitteisto oli yleisesti hyväkuntoinen. Julkujärven ja Hervannan lämpökeskusten parannusehdotusten pohjalta olisi hyvä tehdä lisätutkimuksia, joiden avulla selvitettäisiin uudistus- tai korjaustarve yksityiskohtaisemmin. Lisätutkimukset auttaisivat laitteiston lopullisen kunnostus- ja parannusohjelman laatimisessa.This bachelor’s thesis is about condition audit, proposals for improvements and estimates of their prices in Tampereen Energiantuotanto Ltd.’s fixed heating plants in Pirkanmaa area. The goals were to gather a compact information package about the condition of electrical installations and to estimate the costs of proposals for improvements to support decision making. In order to meet these goals valid standards, safety regulations and running practice were studied and audit minutes were compiled. Based on the minutes summaries and proposals for improvements were made. When estimating the costs of the improvement proposals, retail prices and the warehouse staff’s as well as expert’s knowledge were taken into account. The number of inspected electrical installations was high. The installations had been made in five decades. Electrical installations in good, satisfactory and tolerable conditions were found. There were no installations which would have been in bad condition and would have needed immediate repair. The cost estimates were between 100–50 000 €. The most of the cost estimates were small sums, a few hundred euros. In Julkujärvi and Hervanta heating plants cost estimates were the largest ones. As a conclusion the condition of electrical installations was good in general. In Julkujärvi and Hervanta heating plants further detections should be made in more detailed way in order to make renovation and improvement plans for the installation

Anatomical flow phantoms of the carotid bifurcation: potential application in training and assessment of endovascular device deployment

Doppler ultrasound is widely used in the diagnosis and monitoring of arterial disease. Current clinical measurement systems make use of continuous and pulsed ultrasound to measure blood flow velocity; however, the uncertainty associated with these measurements is great, which has serious implications for the screening of patients for treatment. Because local blood flow dynamics depend to a great extent on the geometry of the affected vessels, there is a need to develop anatomically accurate arterial flow phantoms with which to assess the accuracy of Doppler blood flow measurements made in diseased vessels. In this paper, we describe the computer-aided design and manufacturing (CAD-CAM) techniques that we used to fabricate anatomical flow phantoms based on images acquired by time-of-flight magnetic resonance imaging (TOF-MRI). Three-dimensional CAD models of the carotid bifurcation were generated from data acquired from sequential MRI slice scans, from which solid master patterns were made by means of stereolithography. Thereafter, an investment casting procedure was used to fabricate identical flow phantoms for use in parallel experiments involving both laser and Doppler ultrasound measurement techniques