The effects that thermally induced forces and deformations have on the performance and safety of steel columns subjected to fire are not well understood and are not clearly treated in building codes and standards. This thesis investigates the behavior of steel columns subjected to fire, with an emphasis on studying the significance of thermally induced forces and deformations. The approach used in this research is to conduct a series of analyses of steel columns using the finite element computer program ABAQUS. Columns are modeled in ABAQUS using beam elements that include nonlinear geometry, nonlinear temperature dependent material properties, and initial geometric imperfections. Using the ABAQUS model, a series of analyses are conducted on the behavior of columns under axial compression for temperatures varying from room temperature up to 2400° F. A series of individual columns are analyzed with and without restraint to thermal expansion. A column that is part of a truss is also analyzed to study a simple case of a flexible restraint to thermal expansion. Finally, the behavior of columns that are part of multi-story steel moment frames are investigated. All of the analyses conducted in this research indicate that forces generated by restraint to thermal expansion can have a very large impact on the performance of a steel column in fire. When evaluating the safety of a column in a fire, it is important to recognize that the total axial force in the column is the sum of the force generated by external gravity load on the frame and the force generated by restraint to thermal expansion. The force generated by restrained thermal expansion can be very large, and neglecting this force can lead to unsafe designs. / text

Phytoplankton mirrors changes in the environment and plays an important role in biogeochemical processes. Phytoplankton dynamics is the outcome of both autogenic succession and external disturbances. This thesis focused on the seasonal variation of water column stability and its effects on phytoplankton, particularly considering the influence of mixing events on phytoplankton development. Lake Erken is a dimictic lake with weak and often interrupted summer stratification, which represents an intermediate case between a polymictic lake and a lake with strong summer stratification. There are two diatom phases annually. The spring bloom is caused by pioneer centric diatoms, and the autumn diatom phase is dominated by meroplanktonic diatoms induced by turnover. A summer Cyanobacteria bloom – mainly Gloeotrichia echinulata, depended on the length and stability of stratification. Winter and spring air temperature is found to play an important role in the annual succession of phytoplankton by initiating changes in ice/snow-cover and lake thermal stability and setting the basic status. Instead of starting from zero, the vernal phytoplankton piles up on the overwintering community, this trans-annual ecological memory influences both the composition and diversity and taxonomic distinctness of spring phytoplankton. Water column stability during summer in Lake Erken is mainly influenced by wind-induced turbulence and internal seiches. As thermal stratification develops from early until late summer, variations in stability and gradual deepening of the thermocline depth influence phytoplankton dynamics directly by changing its distribution, and also indirectly by altering the nutrient and light availability. A new disturbance index (DI) was defined to quantify environmental stability/disturbance and tested well to indicate phytoplankton equilibrium status in two summer stratification periods. The concept of species and functional groups was generally used in this study. However, a next generation sequencing based approach was also tested and proved to provide an excellent candidate for revealing distribution patterns of phytoplankton in inland waters.

No description available.

Σκοπός: Πρόκειται για μια προοπτική μελέτη που αφορά στη χειρουργική θεραπεία ασθενών που έπασχαν από εκφυλιστική σπονδυλική στένωση της ΟΜΣΣ σε πολλαπλά επίπεδα (δύο ή περισσότερα). Αποσκοπεί στο να διερευνήσει εάν η συγκεκριμένη χειρουργική τεχνική βελτιώνει τα συμπτώματα των ασθενών και κατά πόσον αυτή η βελτίωση διατηρείται στο χρόνο. Υλικό-Μέθοδος: Σαράντα-ένας ασθενείς συμμετείχαν στην μελέτη, που έλαβε χώρα στην Ορθοπαιδική Κλινική του Πανεπιστημίου Πατρών, από το 1997 έως το 2004. Οι ασθενείς είχαν συμπληρώσει τουλάχιστον 1 έτος μετεγχειρητικής παρακολούθησης. Ο μ.ο. ηλικίας των ασθενών ήταν 61,02 +_ 9,62 έτη (κυμαινόμενη από 33 έως 79 έτη). Οι ασθενείς προεγχειρητικά υποβάλλονταν σε λεπτομερή ακτινολογικό και κλινικό έλεγχο. Ο ακτινολογικός έλεγχος περιελάμβανε απλές και δυναμικές ακτινογραφίες, αξονική τομογραφία (CT), μαγνητική τομογραφία (MRI) και/ή μυελογραφία με μυελο-CT. Ο κλινικός έλεγχος περιελάμβανε τη συμπλήρωση του ερωτηματολογίου της Oswestry Disability Index (ODI) και της Visual Analog Scale (VAS). Βάσει του προεγχειρητικού ελέγχου 23 ασθενείς έπασχαν από εκφυλιστική στένωση σε 2 σπονδυλικά επίπεδα (περιελάμβανε 3 σπονδύλους), σε 16 ασθενείς είχαν προσβληθεί 3 επίπεδα και 2 ασθενείς είχαν προσβληθεί 4 επίπεδα. Επιπλέον αναδείχθηκε ότι 12 ασθενείς έπασχαν από σκολίωση, 18 ασθενείς από σπονδυλολίσθηση 1ου βαθμού, ενώ 9 ασθενείς από τμηματική αστάθεια. Η κλινική εικόνα των ασθενών περιελάμβανε κυρίως άλγος στην οσφύ και στα κάτω άκρα και/ή νευρογενή διαλείπουσα χωλότητα. Επιπλέον 6 ασθενείς παρουσίαζαν σταδιακά επιδεινούμενη νευρολογική σημειολογία. Η χειρουργική τεχνική περιελάμβανε ευρεία οπίσθια αποσυμπίεση των οστικών και συνδεσμικών δομών. Περιελάμβανε αφαίρεση της ακανθώδους απόφυσης του σπονδυλικού πετάλου και του ωχρού συνδέσμου, ώστε να υπάρξει απελευθέρωση του σπονδυλικού καναλιού οπισθίως. Η αποσυμπίεση εκτείνονταν από το έξω όριο του ενός καναλιού των ριζών έως το έξω όριο του άλλου και αφορούσε όλα τα στενωτικά επίπεδα που εκ των προτέρων είχαν καθοριστεί μέσω, του προεγχειρητικού ελέγχου. Η σταθερότητα της Σ.Σ. επιτυγχανόταν με την τοποθέτηση διαυχενικού συστήματος σπονδυλοδεσίας, που εκτείνονταν ένα σπονδυλικό επίπεδο εκατέρωθεν των επιπέδων αποσυμπίεσης. Το τελικό στάδιο της τεχνικής περιελάμβανε τοποθέτηση μοσχευμάτων για την επίτευξη αρθρόδεσης, τα οποία τοποθετούνταν μεταξύ των εγκαρσίων αποφύσεων. Ο μέσος χειρουργικός χρόνος ήταν 228min (από 120min έως 420min). Η παρακολούθηση των ασθενών μετεγχειρητικά γίνονταν σε ετήσια βάση και περιελάμβανε τη συμπλήρωση της ODI και VAS όσον αφορά στο κλινικό σκέλος και απλές και δυναμικές ακτινογραφίες όσον αφορά στο ακτινολογικό σκέλος. Αποτελέσματα: Ο μέσος χρόνος παρακολούθησης των ασθενών ήταν 3,71 +_ 1,54 έτη (κυμαινόμενος από 1 έτος έως 6 έτη). Η συνολική ποιότητα ζωής των ασθενών, όπως εκτιμάται με την ODI, παρουσίασε στατιστικά σημαντική βελτίωση μετεγχειρητικά, που διατηρήθηκε για όλα τα έτη παρακολούθησης. Συγκεκριμένα από 61,06% προεγχειρητικά, βελτιώθηκε στο 16,30% το 4ο μετεγχειρητικό έτος. Στατιστικά σημαντική βελτίωση παρουσίασε και ο πόνος όπως εκτιμήθηκε με τη VAS. Συγκεκριμένα από 7,88 προεγχειρητικά, βελτιώθηκε σε 2,35 το 4ο μετεγχειρητικό έτος. Εκτιμώντας τις επιμέρους παραμέτρους της ODI, διαπιστώνεται πως η μεγαλύτερη βελτίωση επιτεύχθηκε στο άλγος, στην προσωπική φροντίδα, στην ικανότητα καθίσματος, στην ικανότητα ύπνου και στην ικανότητα για ταξίδι. Στις παραπάνω δραστηριότητες ποσοστό ασθενών μεγαλύτερο από 90% παρουσίαζε φυσιολογική ή σχεδόν φυσιολογική δραστηριότητα, με βαθμολογία ‘0’ ή ‘1’ το 4ο μετεγχειρητικό έτος στην 6βάθμια κλίμακα. Η ακτινολογική παρακολούθηση μετεγχειρητικά ανέδειξε αστάθεια σε παρακείμενο επίπεδο σε 2 ασθενείς (4,87%), θραύση μιας βίδας στον Ι1 σπόνδυλο σε 1 ασθενή (2,43%) και χαλάρωση μιας βίδας σε 1 ασθενή (2,43%). Όλοι οι ανωτέρω ασθενείς υποβλήθηκαν σε νέα επέμβαση. Η πιθανότητα συνεπώς για τους ασθενείς της μελέτης να μην υποβληθούν σε νέα επέμβαση λόγω μηχανικής αποτυχίας της αρχικής επέμβασης, ήταν 90,24%. Οι υπόλοιποι ασθενείς παρουσίασαν στον ακτινολογικό έλεγχο πλήρη πώρωση με συνεχή οστική γεφύρωση μεταξύ των εγκαρσίων αποφύσεων άμφω και σταθερότητα σε παρακείμενα επίπεδα. Τέλος οι 39 ασθενείς (95,12%) δήλωσαν ικανοποιημένοι με το αποτέλεσμα της επέμβασης και ότι θα την επαναλάμβαναν κάτω από τις ίδιες συνθήκες. Συμπέρασμα: Η ευρεία οπίσθια αποσυμπίεση συνοδευόμενη από οπισθοπλάγια σπονδυλοδεσία με χρήση υλικών, προσφέρει ικανοποιητικά και αναπαραγόμενα κλινικά και ακτινολογικά αποτελέσματα σε ασθενείς που υποφέρουν από πολυεπίπεδη σπονδυλική στένωση και αστάθεια (εκφυλιστική σκολίωση και/ή εκφυλιστική σπονδυλολίσθηση). Με την παραπάνω τεχνική αποφεύγεται η υποτροπή της στένωσης λόγω άναρχης οστικής αναδόμησης (bone regrowth). Όταν η τεχνική εφαρμόζεται σε προσεκτικά επιλεγμένους ασθενείς οδηγεί σε μικρό ποσοστό επιπλοκών, αποτελώντας μια αξιόπιστη λύση στο πρόβλημα της σημαντικής παθολογίας της σπονδυλικής στήλης. / Aim: This is a prospective study on the surgical treatment of patients who suffered from degenerative spinal stenosis of lumbar spine in multiple levels (2 or more). Our goal was to show if our technique improves substantially patient’s symptoms and if the improvement is long lasting. Patients and Method: Between 1997 and 2004, 41 patients were participated in this study, which took place at the Orthopaedic Department of Patras University Hospital. All patients had completed 1-year postoperative follow up. Mean age was 61 years (range 33 – 79 years). All patients underwent preoperatively detailed radiological and clinical evaluation. Radiological aproach included face, profile and dynamic x-rays, computer tomography (CT), magnetic resorance (MRI) and/or myelography with myelo-CT. Clinical evaluation was done using Oswestry Disability Index (ODI) and Visual Analog Scale (VAS). Twenty-three patients suffered from degenerative stenosis in 2 levels (included 3 vertebral bodies), in 16 patients were involved 3 levels and in 2 patients were involved 4 levels. Furthermore 12 patients suffered from concomitant scoliosis, 18 patients from concomitant spondylolisthesis (1st grade), 9 patients from segmental instability and 2 patients from scoliosis and spondylolisthesis. Patients’ symptoms were low back pain, sciatica and/or neurologic intermittent claudication. In 6 patients neurologic deterioration was observed. Surgical technique was wide posterior decompression. This included removal of spinous process, vertebral lamina and ligamentum flavum, and lead to fully posterior exposure of the spinal canal. Decompression was taken place in all the stenotic segments and was extended from one to another root canal in each segment. In order to achieve stability of the spine we used transpedicular screw fixation system, which extended one segment above and one below the decompressed area. Finally we used osseous graft and allograft between transverse processes. Mean surgical time was 228 (120-420) min. Patients’ follow up was done once per year and included the completion of ODI and VAS and face profile and dynamic x-rays for clinical and radiological assessment respectively. Results: Mean follow up was 3,7 (1-6) years. The quality of patients’ life, as is estimated with ODI, showed substantial improvement, which lasted all years. In specific from 61% preoperatively, improved to 16% the 4th postoperative year. Pain also presented statistical significant improvement, as is estimated with VAS. In specific from 7,9 preoperatively improved to 2,3 the 4th postoperative year. Evaluation of ODI’s parameters showed that the greater improvement was achieved in pain, personal care, sitting, sleeping and traveling. More than 90% of the patients had normal or nearly normal activity in these aforementioned parameters, the 4th postoperative year. Two patients had instability in an adjacent level (4,9%). Also one screw breakage in 1 patient (2,4%) and one screw loosening in another one (2,4%), both in S1 vertebral, was observed. These 4 patients underwent second surgical intervention due to instability. Finally there was possibility 90,2% for the patients not to underwent second operation due to mechanical failure. The rest of the patients presented with solid fusion, confluent osseous bridging between the transverse processes and stable adjacent vertebral levels. Conclusions: Wide posterior decompression combined with posterolateralinstrumented fusion, lead to satisfactory and reproducible clinical and radiological results to patients who suffer from degenerative lumbar spinal stenosis in multiple levels with concomitant instability (degenerative scoliosis and/or degenerative spondylolisthesis). The aforementioned technique avoids substantial bone regrowth and stenosis recurrence. Proper use in carefully selected patients has low complication rate, giving us a good and long-lasting result.

Water column methane measurements have been used to understand both the global distribution of methane in the oceans and the local flux of methane from geologic sources on the continental margins, including methane vents and gas-hydrate-bearing sites. We have measured methane concentrations in 1607 water samples collected along the central California continental margin. Methane supersaturation of the surface mixed layer (0-50 msbsl) is widespread and above a well-defined subsurface particle maximum (~50 mbsl) that generally corresponds with the pycnocline. Local production of methane appears to be occurring in the surface mixed layer above the particle maximum and may not be particle-associated. Methane concentrations in water column CTD cast profiles and ROV-collected bottom waters obtained in Partington, Hueneme, Santa Monica, and Redondo submarine canyons increase towards the seafloor and are distinctly higher (up to 186 nM) compared to open-slope and shelf waters at similar depths. These values are in excess of measured surface water methane concentrations and could not be generated by mixing with surface water. Elevated methane concentrations in these submarine canyons and persistent mid-water methane anomalies in Ascension and Ano Nuevo Canyons could result from restricted circulation and/or proximity to gas vents, seafloor exposure of methane gas hydrates, recently-eroded methane-rich sediment, submarine discharge of methane-rich groundwater, or particle-associated methane production. On the Santa Barbara shelf water column methane profiles near known gas vents also increase in concentration with increasing depth. Thus, elevated bottom water methane concentrations observed in submarine canyons may not be diagnostic of proximity to methane vents and may be caused by other processes.

Projektet omfattade en jämförelsestudie avseende stomsystem. Studien undersökte ramverk och fackverk/balk/pelar-system och genomfördes självständigt med stöttning av Ramböll AB´s kontor i Falun. Syftet var främst att undersöka vilka skillnader det finns mellan tvåledsramar och fackverk/balk/pelar-system för lätta hallbyggnader och försöka få klarhet i varför fackverk/balk/pelar-system är det dominerande systemet i Sverige eftersom övriga Europa har tagit en annan utveckling och domineras av tvåledsramar. Studien undersöker skillnaderna mellan systemen i en hallbyggnad med förutbestämda mått i stål.Inledningsvis gjordes en litteraturstudie för att få en bredare bakgrund av systemen och en bättre förståelse om förutsättningarna för varje system. Efter litteraturstudien kunde sedan ett typhus och beräkningsunderlag för jämförelsestudien tas fram. Även en enkätstudie gjordes med syftet att skapa en tydlig bild av vilket stomsystem konstruktörer i Sverige oftast väljer och varför. Resultatet av studien visade att tvåledsramar ger en ökad kostnad jämfört med fackverk/balk/pelar-system i materialåtgång och framställning samt att beräkningarna blir mer komplicerade. Skulle fortsatta studier göras med dessa system i byggnader med andra mått skulle det kanske gå att få fram speciella mått på byggnader där kostnaden för tvåledsramar blir densamma som för fackverk/balk/pelar-system och därför är ett likvärdigt alternativ som stomsystem.En viktig slutsats från projektet är att tvåledsramar används mycket mer sällan än fackverk/balk/pelar-system som stomsystem i lätta hallbyggnader i Sverige på grund av att kostnaderna blir mycket högre med tvåledsramar och att det är ett mer komplicerat system i beräkningsarbetet. De viktigaste slutsatserna från jämförelsestudien går att sammafatta som följande: Tvåledsramar är dyrare att använda. Tvåledsramar är ett mer komplicerat system beräkningsmässigt. Traditionen av att använda tvåledsramar finns inte och därför används inte systemet. / The project included a comparison study on frame systems. The study investigated framework and truss/beam/column-system and was conducted independently with support of Ramboll AB 's office in Falun. The aim was primarily to examine what differences there are between frameworks with two joints and truss/beam/column-systems for light industrial buildings and try to determine why the truss/beam/column-system is the dominant system in Sweden because the rest of Europe has taken a different development and dominated by framework with two joints. The study examines the differences between the systems in a industrial building with predetermined dimensions in steel.Initially, a literature study was conducted to gain a broader view of the systems and to create a better understanding for the conditions for each system. After the literature study was conducted could a exampelhouse and underlay for the comparison study be developed. A survey study were also conducted and the purpose was to create a clear picture of which system the frame system designers in Sweden usually choose and why. The results of the study showed that frameworks with two joints give an increased cost compared with truss/beam/column-system in material consumption and production, and the calculations become more complicated for the framwork. Should further studies be done with these systems in buildings with other measurements, it might possible to obtain specific measures of buildings where the cost of frameworks with two joints will be the same as for a building with truss/beam/column-system and therefore become an equivalent alternative.An important conclusion of this project is that a framework with two joints is used much more rarely than truss/beam/column-system as frame systems in light industrial buildings in Sweden because the cost will be much higher with a framework with two joints and that it is a more complicated system in the computational work . The main conclusions from comparative study can be summarized as follows: Framwork with two joints is more expensive to use. Framework with two joints is a more complicated system computationally. The tradition of using framework with two joints does not exist and it's therefore the system does not being used.

There are about 250 new spinal cord injury cases in Lithuania each year. Usually, young people of a „working age” are getting injured. Men are getting spinal cord injuries four times often than women. Researches were made in Wellness center of Vilkpėde in year 2004 and year 2005, in Vilnius (rehabilitation takes 35 days). In this supportive rehabilitation participated 24 patients who have experienced cord injuries in a past 2 years. There were 32 – 45 years old, both sex patients (79,2 % males, 20,8 % females). Participants were divided into two groups. There were 12 patients with spinal cord injuries participating in each group (paraplegics). In the first (control) group researched patients were treated only with kinesitherapy, and the second group was experimental where patients were treated using K.Nyshi method. There were made 40 procedures for the patients in each group. Purpose of this research is – the influence of K. Nyshi method for the patients with spinal cord injures. Goal of this work is – to compare the efficiency of K. Nyshi method and kinesitherapy; to evaluate patient’s functional independence; shoulder joint flexibility. During this research the following evaluation tests were used – functional independence, spinal muscle strength, waist muscular strength balance, shoulder joint flexibility, waist flexibility. Chances of bedsores were evaluated by scale of Norton. After spinal cord injuries, in period after traumas or when disease was irascible and heavy... [to full text]

Didelis dėmesys skiriamas natūralių antioksidantų paieškai ir įvertinimui augalinės kilmės vaistinėse ir maistinėse žaliavose. Mokslinių tyrimų objektais yra didelis skaičius augalų rūšių, ekstraktų, maisto papildų ir vaistinių preparatų. Tiriamųjų darbų našumas ir informatyvumas, be abejonės, priklauso nuo pasirinktų metodų tinkamumo, jautrumo ir efektyvumo. Darbo tikslas yra išvystyti bei įteisinti pokolonėlinę ESC-DPPH metodiką ir ją pritaikyti laisvuosius radikalus surišančių žinomų ir nežinomų junginių, esančių vaistinėje augalinėje žaliavoje, antioksidantinio aktyvumo įvertinimui. ESC išskirstyti junginiai nustatomi UV detektoriumi 275 nm ilgio bangoje; mobili fazė su analitėmis per maišymo trišakį tiekiama į reakcijos kilpą, kur 0,4 ml/min tėkmės greičiu paduodamas DPPH tirpalas. Reakcijos kilpa sujungta su UV/Vis tipo detektoriumi, matuojančiu pratekančio tirpalo absorbciją esant 520 nm bangos ilgiui. Nustatyta, jog Crataegus monogyna lapuose vyraujantis flavonoidas viteksino ramnozidas nepasižymi antioksidantiniu aktyvumu. Reikšmingiausias antioksidantas C. monogyna lapuose ir žieduose yra chlorogeno rūgštis. Didžiausiu antioksidantiniu aktyvumu Origanum vulgare augalinėje žolėje pasižymi rozmarino rūgštis. Achillea millefolium ekstraktuose identifikuotos šios analitės, turinčios radikalus surišantį aktyvumą: chlorogeno rūgštis, luteolin-7-O-gliukozidas, rutinas ir luteolinas. / The most important attention is paid to the search of natural antioxidants and their evaluation in medicinal and food raw materials of plant origin. A number of plants, their extacts, food products and medicinal preparations appear to be objects of scientific research. Effectiveness and informative character of research, undoubtedly, depend on relevance, sensitivity and efficiency of the methods chosen. Aim of this work is development and validation of post column HPLC-DPPH method as well as its application in antioxidant activity evaluation of known and unknown compounds fixing free radicals and existing in medicinal plant raw materials. HPLC separated compounds are identified at wave length of 275 nm and then the mobile phase with analytes flows by mixing tee to the reaction coil, where DPPH reagent solution is supplied. The solution flow rate – 0,4 ml/min. The reaction coil is connected with UV/Vis type detector, which measures absorption of flowing solution at wave length of 520 nm. It was dermined that vitexin rhamnoside, the dominant compound in the leaves of Crataegus monogyna, is not significant radical sacavenger. The most active antioxidant in leaves and the flowers of C. monogyna is chlorogenic acid. The most active antioxidant in Origanum vulgare raw materials is rosmarinic acid. Identified analytes in the extracts of Achillea millefolium that possessed radical scavenging properties were chlorogenic acid, luteolin-7-O-glucoside, rutin and luteolin.

The relative contributions of bedrock geology, radiometric uranium, till permeability and surficial geology were assessed as predictors of radon in indoor air in the Halifax Regional Municipality (HRM), NS, Canada. Bedrock geology and radiometric uranium were statistically significant predictors (14.4%) of indoor radon, based on available indoor radon data. Permeability was not among the predictors, which was surprising given its importance in past studies. In a follow up field analogue study done in laboratory columns, the permeability and diffusivity, as gas transport mechanisms, were found, as suspected, to be important drivers on the concentrations of radon-222 detected. Given the variable thickness of till in the HRM (< 0.5 m to > 3 m), these experiments highlighted the significance of till thickness, composition, and permeability in predicting the radioactive radon-222 potential.

No description available.