Load transfer mechanism of concrete screws

Even though the market and development for concrete screws has been increasingly rising in recent years, the load transfer mechanism of concrete screws has not yet been fully investigated. Therefore, different tests of concrete screws made of galvanized and stainless steel were performed in concrete C20/25 and C50/60. The main aim is to measure the strain along the embedment depth. This will be achieved by using strain gauges that get placed in a centrically drilled borehole through the concrete screw. To get a comparison to the mechanism of the screws the same process will be executed in threaded rods used as a part of bonded anchors. Due to the fact that the threaded cuts of concrete screws have geometrical similarities to bonded anchors, it was examined if the load transfer of both fasteners is related and may be compared. The results of the testing have shown that the load transfer mechanism of both fastener types is similar in low-strength concrete showing a concrete cone failure. In high strength concrete due to the mainly occurring steel failure the maximum measured strains at the maximum load step are not comparable. However, at lower load steps where the steel does not exceed the yield strength the results show a similar load transfer mechanism, too

Long-term effect of latanoprost/timolol fixed combination in patients with glaucoma or ocular hypertension: A prospective, observational, noninterventional study

Background: Prospective, observational studies that enroll large numbers of patients with few exclusion criteria may better reflect actual ongoing clinical experience than randomized clinical trials. Our purpose was to obtain efficacy and safety information from a cohort of subjects exposed to latanoprost/timolol fixed combination (FC) for [greater than or equal to]18 months using a prospective, observational design. Methods: In all, 577 office-based ophthalmologists in Germany switched 2339 patients with glaucoma or ocular hypertension to latanoprost/timolol FC for medical reasons. Follow-up visits were scheduled for every 6 months over 24 months; physicians followed usual care routines. Intraocular pressure (IOP), visual field status, optic nerve head findings, and adverse events were recorded. Efficacy parameters were evaluated for the per protocol (PP) population; the safety population included subjects receiving [greater than or equal to]1 drop of FC. Physicians rated efficacy, tolerability, and subject compliance at month 24. Results: Of the 2339 subjects switched to latanoprost/timolol FC (safety population), the primary reasons for switching were inadequate IOP reduction (78.2%) and desire to simplify treatment with once-daily dosing (29.4%; multiple reasons possible). In all, 1317 (56.3%) subjects completed the study, and 1028 (44.0%) were included in the PP population. Most discontinuations were due to loss to follow-up. Change in mean IOP from baseline to month 6 was -4.0 +/- 4.31 mmHg, a reduction that was maintained throughout (P<0.05 for change at all time points). By investigator assessments, optic disc parameters and visual field were stable over 24 months, and there was no relationship between IOP reduction over 24 months and development of a visual field defect. More than 90% of physicians rated latanoprost/timolol FC as "very good" or "good" for efficacy (PP population), tolerability, and compliance. The FC was safe and well tolerated. No change in iris color was reported by most subjects (83.1%) at month 24. Conclusions: Over 24 months, latanoprost/timolol FC effectively lowers IOP levels and is well tolerated in patients with glaucoma or ocular hypertension who change from their previous ocular hypotensive therapy for medical reasons. Investigator assessments found optic disc parameters and visual field to be stable throughout 24 months of follow-up

Strengthening of Reinforced Concrete Beams with Externally Mounted Sequentially Activated Iron-Based Shape Memory Alloys

Iron based shape memory alloys (Fe-SMA) have recently been used as active flexural strengthening material for reinforced concrete (RC) beams. Fe-SMAs are characterized by a shape memory effect (SME) which allows the recovery of previously induced plastic deformations through heating. If these deformations are restrained a recovery stress is generated by the SME. This recovery stress can be used to prestress a SMA applied as a strengthening material. This paper investigates the performance and the load deformation behavior of RC beams strengthened with mechanical end anchored unbonded Fe-SMA strips activated by sequentially infrared heating. The performance of a single loop loaded and a double loop loaded SMA strengthened RC beam are compared to an un-strengthened beam and a reference beam strengthened with commercially available structural steel. In these tests the SMA strengthened beam had the highest cracking load and the highest ultimate load. It is shown that the serviceability behavior of a concrete beam can be improved by a second thermal activation. The sequential heating procedure causes different temperature and stress states during activation along the SMA strip that have not been researched previously. The possible effect of this different temperature and stress states on metal lattice phase transformation is modeled and discussed. Moreover the role of the martensitic transformation during the cooling process on leveling the inhomogeneity of phase state in the overheated section is pointed out

Identification and replication of the interplay of four genetic high risk variants for urinary bladder cancer

Little is known whether genetic variants identified in genome-wide association studies interact to increase bladder cancer risk. Recently, we identified two- and three-variant combinations associated with a particular increase of bladder cancer risk in a urinary bladder cancer case-control series (IfADo, 1501 cases, 1565 controls). In an independent case-control series (Nijmegen Bladder Cancer Study, NBCS, 1468 cases, 1720 controls) we confirmed these two- and three-variant combinations. Pooled analysis of the two studies as discovery group (IfADo-NBCS) resulted in sufficient statistical power to test up to four-variant combinations by a logistic regression approach. The New England and Spanish Bladder Cancer Studies (2080 cases and 2167 controls) were used as a replication series. Twelve previously identified risk variants were considered.The strongest four-variant combination was obtained in never smokers. The combination of rs1014971[AA] near APOBEC3A and CBX6, SLC14A1 exon SNP rs1058396[AG,GG], UGT1A intron SNP rs11892031[AA], and rs8102137[CC,CT] near CCNE resulted in an unadjusted odds ratio of 2.59 (95% CI = 1.93-3.47; P = 1.87x10-10), while the individual variant odds ratios ranged only between 1.11-1.30. The combination replicated in the New England and Spanish bladder Cancer Studies (ORunadjusted=1.60, 95% CI = 1.10-2.33; P = 0.013). The four-variant combination is relatively frequent, with 25% in never smoking cases and 11% in never smoking controls (total study group: 19% cases, 14% controls). In conclusion, we show that four high risk variants can statistically interact to confer increased bladder cancer risk particularly in never smokers

Entwicklung eines ökotouristischen Nutzungskonzeptes für den ehemaligen Militärstandort Hjerkinn Skytefelt im Nationalpark Dovrefjell-Sunndalsfjella in Mittel-Norwegen

Der Ökotourismus hat sich in den letzten Jahren zu einer Tourismussparte entwickelt, die nicht nur immer mehr Interessenten unter den Nutzern findet, sondern auch vielfältige Forschungsmöglichkeiten eröffnet.rnAus interdisziplinärer Betrachtungsweise kann man sowohl in den Gebieten der Biologie, der Wirtschaft, der Geographie, aber auch der Politik forschend tätig werden. rnDa der Tourismus in den letzten Jahren eine immer größere Bedeutung gerade für Länder mit weitestgehend intakten Naturressourcen erlangt hat, stellt sich die Frage inwieweit die Wirtschaft eines Landes auf diese Einnahmequelle angewiesen ist und ob nicht die ökologischen Belange immer weiter in den Hintergrund treten.rnAus diesem Ansatz heraus erfolgte zunächst eine qualitative und quantitative Bestandsaufnahme, die ein klares Bild vom derzeitigen Zustand in der Region ermöglicht. Darüber hinaus werden im Rahmen der Untersuchungen Zukunftsperspektiven aufgezeigt. Diese sollen verdeutlichen, inwieweit man steuernd in solche dynamischen Entwicklungsprozesse eingreifen kann oder soll.rnDie Schwerpunkte dieser Arbeit liegen in dem Bereich der Befragung von Touristen und in der Ausarbeitung eines digitalen Geländemodells zur späteren Nutzung in einem aufzubauenden Nationalpark-Infozentrum. Auf der Grundlage dieser Untersuchungen wurde ein touristisches Nutzungskonzept entwickelt und auf seine ökologischen Umsetzungschancen hin untersucht. Der Aspekt des Ökotourismus wird einleitend erörtert und definiert. Anschließend werden die Potenziale der norwegischen Tourismuswirtschaft untersucht. Die Befragungsergebnisse sowohl der norwegischen Besucher als auch der ausländischen Touristen werden in verschiedenen Korrelationen näher untersucht.rnEin gesonderter Bereich der Untersuchungen gilt dem Problemfeld des Wildcampings in Norwegen. Die dramatischen Entwicklungen der letzten Jahre rufen immer mehr Aktivisten auf den Plan. Da die Deutschen die größte Besuchergruppe darstellen, wurden innerhalb der Jahre 2003 bis 2006 Einzelinterviews geführt, um einen Überblick über das Übernachtungsverhalten der Deutschen in Norwegen gewinnen zu können. In den vergangenen 10 Jahren sind die deutschen Besucherzahlen in Norwegen leicht rückläufig, während die der Niederländer kontinuierlich steigen.rnAuf diesen Ergebnissen basierend wurden problemzentrierte Interviews mit Wohnmobilreisenden, der größten Gruppe der Individualreisenden, durchgeführt. rnMehr als 600.000 Nächte pro Jahr verbrachten die deutschen Wohnmobilreisenden außerhalb der Campingplätze, was ökologische und ökonomische Auswirkungen hat und nicht mehr mit dem in Norwegen geltenden „Allemansrett“, dem Jedermannsrecht, vereinbar ist. rnGerade die Touristen, die mit dem Wohnmobil reisen, können nur schwer mit anderen Reisenden verglichen werden, da sie mit einer völlig anderen Reiseauffassung mehr oder weniger autark unterwegs sind. Dabei legen sie besonders große Distanzen zurück und haben sich zum Ziel gesetzt, möglichst viel in kurzer Zeit zu sehen und zu erleben. Für alle Touristengruppen wurde untersucht, auf welchem Weg die Informationen für die geplante Reise beschafft wurden. Der Reiseführer ist der hauptsächliche Informationslieferant und ist teilweise für das Verhalten der Urlauber mitverantwortlich. Es konnte festgestellt werden, dass das Image des Landes und die Reisemotive das Reiseverhalten und die Wahrnehmung determinieren. Eine Untersuchung der so genannten Pull- und Push-Faktoren ergab, dass die nahezu noch unberührte Natur, die raue Landschaft sowie Ruhe und Erholung die entscheidenden Pull-Faktoren für Norwegenreisende sind. Dabei überprägt das Image Norwegens als „wildes Naturland“ die Wahrnehmung für verschiedene Problembereiche, die in Norwegen, wie auch in vielen anderen Ländern Europas, durchaus vorhanden sind. rnProblemfelder, wie Landschaftsausbeutung, Wildcamping, reduziertes Konsumverhalten und damit einhergehende rückläufige Besucherzahlen, können aber durch innovative Tourismuskonzepte und neue Reiseformen abgebaut werden. Hierbei sind Medien, wie Reiseführer, Internet und Reisemagazine, in die Pflicht zu nehmen.In the last years the ecotourism has developed into a section of tourism, which not only has more and more prospective customers, but also opened various possibilities for research.rnFrom an interdisciplinary point of view research can be done in the fields of biology, economics, geography as well as in the field of politics.rnSince tourism gained a growing importance in the last years, especially for the countries with nearly intact nature resources, questions arise to what extent the economy of a country is dependent on this source of income and if not the ecological interests have to step back deeper and deeper in to the background. Out of this attempt a qualitative and quantitative appraisal, which allows a clear view of the present condition in the region, took place. Beyond this future perspectives will be identified.rnThese are to clarify, if or if not one can affect the conditions in such dynamic development processes and to what extent. This study has two main focuses:rnrnNumber one is the survey which was done with the tourists and number two is the elaboration of a digital land model for later use e.g. in the nationalpark center which has to be built up. Based on these researches a concept was developed for touristic use of the area and this concept was tested under an ecological aspect concerning the chances of its realisation.rnInitiatively the aspect of ecotourism is discussed and defined. Afterwards the potential of the Norwegian tourism economy is examined. The survey results of both, the Norwegian as well as the foreign tourists, are evaluated more closely under different correlations. A separate field of this assay solely refers to the big problem of “offsite camping” in Norway. rnMore and more activists appear for this target as this topic develops dramatic in the last years. rnSince the Germans represent the largest group of visitors, single interviews were made in the years 2003, 2004, 2005 and 2006. The intention was to gain an overview of the accommodation behaviour of the Germans in Norway.rnIn the past ten years the number of German visitors in Norway is declining, while those of the Dutchman are continuously rising. rnBased on the results personal interviews with this issue as a main topic were accomplished. These were only made with the largest group of individual travellers, the tourists with mobile homes.rnThe Germans with mobile homes spent more than 600,000 nights per year outside of camping grounds. This has ecological and economical effects and is incompatible with the Norwegian “Allemansrett”, which allows people who travel by foot or by bicycle to camp every where as long as they leave the place in the morning in the same way they found it the night before and as long as they stay away at least 200 meters from the next private ground.rn rnOf all tourists, the ones who travel with a mobile home can be compared badly with other travellers, since they are on their way with a completely different perception of travelling, more or less self-sufficient as all the other travellers.rnIn doing so they cover particularly large distances and their ambition is to see and experience as much as possible within a short time. It was analysed for all groups of tourists in which way information for the planned journey was gathered. Primarily the travel guide is the provider for information and is therefore partly responsible for the behaviour of the holidaymaker.rnIt could be stated that the Image of the country and the travel motives determine the perceptions and the behaviour during the journey.rnFrom an investigation of the so called “Pull”- and “Push”-factors it resulted that the almost unaffected nature, the rough landscape as well as recovery are the crucial “Pull”-factors for travellers who come to Norway.rnThe image of Norway as a country with wild and unaffected nature conceals the sense for the different areas with problems which are exist in Norway, likely to a lot of other countries in Europe.rnProblem areas as landscape exploitation, camping outside of camping sites, reduced consumer behaviour, accompanied by declining numbers of visitors, can be diminished by innovative tourism- concepts and new forms of travel.rnHere media, such as travel guides, internet and travel magazines, has to be reminded of their duties

Assessment of the Deterioration State of Post-Installed Bonded Anchors Using Ultrasonic

The assessment of already installed anchorages for a possible exceeding of the service load level is a question that is gaining more and more importance, especially in building maintenance. Bonded anchors are of particular interest here, as the detection of a capacity reduction or load exceedance can cause damage to the concrete-bonded mortar behavior. This article investigates the extent to which ultrasonic methods can be used to make a prediction about the condition of anchorages in concrete and about their load history. A promising innovative assessment method has been developed. The challenges in carrying out the experimental investigations are the arrangement of the transducers, the design of the test set-up and the applicability of direct, indirect or semidirect ultrasonic transmission. The experimental investigations carried out on a test concrete mix and a bonded anchor system show that damage to the concrete structure can be detected by means of ultrasound. The results indicate the formation of cracks and therefore a weakening of the response determined by means of direct, indirect and semidirect ultrasonic transmission. However, for application under non-laboratory conditions and on anchors with unknown load history, the calibration with a reference anchor and the identification of the maximum load is required. This enables a referencing of the other loaded anchors to the unloaded conditions and allows an estimation of the load history of individual anchors

Strengthening of Reinforced Concrete Beams with Externally Mounted Sequentially Activated Iron-Based Shape Memory Alloys

Iron based shape memory alloys (Fe-SMA) have recently been used as active flexural strengthening material for reinforced concrete (RC) beams. Fe-SMAs are characterized by a shape memory effect (SME) which allows the recovery of previously induced plastic deformations through heating. If these deformations are restrained a recovery stress is generated by the SME. This recovery stress can be used to prestress a SMA applied as a strengthening material. This paper investigates the performance and the load deformation behavior of RC beams strengthened with mechanical end anchored unbonded Fe-SMA strips activated by sequentially infrared heating. The performance of a single loop loaded and a double loop loaded SMA strengthened RC beam are compared to an un-strengthened beam and a reference beam strengthened with commercially available structural steel. In these tests the SMA strengthened beam had the highest cracking load and the highest ultimate load. It is shown that the serviceability behavior of a concrete beam can be improved by a second thermal activation. The sequential heating procedure causes different temperature and stress states during activation along the SMA strip that have not been researched previously. The possible effect of this different temperature and stress states on metal lattice phase transformation is modeled and discussed. Moreover the role of the martensitic transformation during the cooling process on leveling the inhomogeneity of phase state in the overheated section is pointed out

A Randomized Trial of a Schlemm's Canal Microstent with Phacoemulsification for Reducing Intraocular Pressure in Open-Angle Glaucoma

Purpose: To assess the safety and effectiveness of the Hydrus Microstent (Ivantis, Inc, Irvine, CA) with concurrent cataract surgery (CS) for reducing intraocular pressure (IOP) in open-angle glaucoma (OAG). Design: Prospective, multicenter, randomized, single-masked, controlled clinical trial. Participants: One hundred eyes from 100 patients 21 to 80 years of age with OAG and cataract with IOP of 24 mmHg or less with 4 or fewer hypotensive medications and a washed-out diurnal IOP (DIOP) of 21 to 36 mmHg. Methods: On the day of surgery, patients were randomized 1:1 to undergo CS with the microstent or CS alone. Postoperative follow-up was at 1 day, 1 week, and 1, 3, 6, 12, 18, and 24 months. Washout of hypotensive medications was repeated at 12 and 24 months. Main Outcome Measures: Response to treatment was defined as a 20% or more decrease in washed out DIOP at 12 and 24 months of follow-up compared with baseline. Mean DIOP at 12 and 24 months, the proportion of subjects requiring medications at follow-up, and the mean number of medications were analyzed. Safety measures included change in visual acuity, slit-lamp observations, and adverse events. Results: The proportion of patients with a 20% reduction in washed out DIOP was significantly higher in the Hydrus plus CS group at 24 months compared with the CS group (80% vs. 46%; P = 0.0008). Washed out mean DIOP in the Hydrus plus CS group was significantly lower at 24 months compared with the CS group (16.9±3.3 mmHg vs. 19.2±4.7 mmHg; P = 0.0093), and the proportion of patients using no hypotensive medications was significantly higher at 24 months in the Hydrus plus CS group (73% vs. 38%; P = 0.0008). There were no differences in follow-up visual acuity between groups. The only notable device-related adverse event was focal peripheral anterior synechiae (1–2 mm in length). Otherwise, adverse event frequency was similar in the 2 groups. Conclusions: Intraocular pressure was clinically and statistically significantly lower at 2 years in the Hydrus plus CS group compared with the CS alone group, with no differences in safety

Identification and replication of the interplay of four genetic high risk variants for urinary bladder cancer

Little is known whether genetic variants identified in genome-wide association studies interact to increase bladder cancer risk. Recently, we identified two- and three-variant combinations associated with a particular increase of bladder cancer risk in a urinary bladder cancer case-control series (IfADo, 1501 cases, 1565 controls). In an independent case-control series (Nijmegen Bladder Cancer Study, NBCS, 1468 cases, 1720 controls) we confirmed these two- and three-variant combinations. Pooled analysis of the two studies as discovery group (IfADo-NBCS) resulted in sufficient statistical power to test up to four-variant combinations by a logistic regression approach. The New England and Spanish Bladder Cancer Studies (2080 cases and 2167 controls) were used as a replication series. Twelve previously identified risk variants were considered.The strongest four-variant combination was obtained in never smokers. The combination of rs1014971[AA] near APOBEC3A and CBX6, SLC14A1 exon SNP rs1058396[AG,GG], UGT1A intron SNP rs11892031[AA], and rs8102137[CC,CT] near CCNE resulted in an unadjusted odds ratio of 2.59 (95% CI = 1.93-3.47; P = 1.87x10-10), while the individual variant odds ratios ranged only between 1.11-1.30. The combination replicated in the New England and Spanish bladder Cancer Studies (ORunadjusted=1.60, 95% CI = 1.10-2.33; P = 0.013). The four-variant combination is relatively frequent, with 25% in never smoking cases and 11% in never smoking controls (total study group: 19% cases, 14% controls). In conclusion, we show that four high risk variants can statistically interact to confer increased bladder cancer risk particularly in never smokers