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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Preliminary Report on the Effect of Roentgen Rays on the Formed Elements of Avian Blood

Berger, Gillett 08 1900 (has links)
This problem consists primarily in determining the numerical value of the leukocytes after different amounts of roentgen rays had been applied to the subjects. The Atomic Energy Commission set up a problem concerning the effects of roentgen rays on the fertility in chickens, and grants were given to two institutions to study this. The blood work in this paper was an off-shoot from one of these five fertility grants.
2

O conceito de descoberta científica: os raios de Roentgen como estudo de caso / The concept of scientific discovery: the Roentgen rays as a case study

Cestari Junior, Decio Hermes 17 September 2015 (has links)
Made available in DSpace on 2016-04-28T14:16:23Z (GMT). No. of bitstreams: 1 Decio Hermes Cestari Junior.pdf: 1836314 bytes, checksum: e7d63f5b7f7450761733426e00c19a54 (MD5) Previous issue date: 2015-09-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work aims to analyse the concept of discovery in the nineteenth century by exploring the behaviour of scientists and the common people at that time. We have started by studying original documents on X rays published by Wilhelm Conrad Roentgen. We have found that some evidences proving that scientists claim the discoveries to themselves. This claim was important because it led them to achieve an elevated scientific recognition. To develop this work we have considered different scientific approaches in order to understand the behaviour of members of scientific community. Therefore, the fields of philosophy of science and sociology of science were also applied to support some parts of this research. By analysing publications of that time it was possible to understand the concept of scientific discovery among common people during the nineteenth century. In the last part of our research we have analysed the concept of science currently used in popular science books. We could find misconceptions such as trying to explain science from discoveries or describing experiments as if they were crucial, that is, the story of winners. It's possible to note that some of those misconceptions found in the common sense of the nineteenth century can also be found in the current popular science books / Este trabalho tem por objetivo analisar o conceito de descoberta científica no final do século XIX a partir do estudo do comportamento dos cientistas e da sociedade da época. Iniciamos nosso trabalho com a análise dos documentos originais publicados por Wilhelm Conrad Roentgen, nos quais encontramos evidências de que o cientista reivindica prioridade sobre a descoberta. Essa prioridade é importante para que o cientista receba o reconhecimento de seus pares. Para desenvolver este trabalho foi necessário analisar o comportamento dos membros da comunidade científica a partir de diferentes perspectivas, para isso, buscamos referências em outros campos do conhecimento, como a filosofia da ciência e a sociologia da ciência. Através da análise dos periódicos do final do século XIX e início do século XX, foi possível compreender a concepção de descoberta predominante no senso comum da sociedade daquele período. Na parte final deste trabalho analisamos a concepção de descoberta científica utilizada nos livros de divulgação científica atuais. Encontramos abordagens que procuram explicar a ciência a partir das descobertas científicas ou de experimentos considerados definitivos, ou seja, a história dos vencedores. Observamos que é possível encontrar nos atuais livros de divulgação científica concepções de descoberta semelhantes às encontradas no senso comum do século XIX
3

Kinematics and fixation of total knee arthroplasties : a clinical, radiographic, scintimetric, and roentgen stereophotogrammetric evaluation

Nilsson, Kjell G. January 1992 (has links)
Aseptic loosening of the tibial component is an important cause of failure after total knee arthroplasty. Bone destruction often claimed to be caused by the cement makes the revision difficult. In order to treat younger patients, uncemented fixation has been introduced, but the etiology to loosening is multifactorial and only partly known. Early detection of implant migration facilitates research in this field but is difficult using conventional techniques. In this study modified versions of roentgen stereophotogrammetric analysis (RSA) were developed to obtain accurate and standardized evaluations facilitating comparison between prosthetic designs. The method was used to record the efficacy of cemented and uncemented fixation of different designs of the tibial component, to determine the accuracy of scintimetry in the detection of early aseptic loosening, and to analyse the in vivo kinematics of knee arthroplasties with different design and stability between the joint surfaces. Forty-three arthroplasties with comparatively high inherent stability of the joint surfaces were randomized to cemented or uncemented fixation of the tibial component. In all groups micromovements were rather large, but with no differences between the cemented and uncemented components. The preoperative diagnosis (arthrosis OA, n=25; rheumatoid arthritis RA, n=18) did not influence the magnitude of micromotion. 20 arthroplasties with the same design as above but equipped with an intramedullary stem, were randomized to cemented or uncemented fixation in patients with RA. Cement improved the fixation. Uncemented stemmed components displayed micromovements seemingly larger than unstemmed ones. 34 arthroplasties with an unconstrained design of the joint area and fixed to the tibia with four pegs were randomized to cemented or uncemented fixation in patients with OA. When used uncemented 4 screws were added. Compared with previously investigated designs small micromotions were recorded, and especially in the cemented cases. Uncemented components with thin polyethylene inserts displayed larger initial micromotions. The preoperative deformity influenced the direction of the micromotion. 33 knees were followed prospectively with RSA and scintimetry to evaluate any correlation between these methods. Low activity under the tibial component at 2 years implied prosthetic stability, whereas high activity indicated instability or high bone remodelling caused by the preoperative malalignment. The in vivo kinematics in three different designs of knee arthroplasties were analyzed during active flexion and extension without weight-bearing. Each type of prosthesis displayed design-specific abnormalities when compared with a normal material. Pronounced posterior tibial translations were recorded during flexion regardless whether the posterior cruciate ligament had been sacrificed or not. Data from the kinematic and the fixation studies suggest that movements restricted by the design of the joint area are transmitted to the bony interface with design-specific micromotions as the result. Analysis of knee joint kinematics during extension and weight-bearing revealed small alterations compared with non-weight-bearing. Evaluation of the three-dimensional movements in terms of helical axis rotations and translations confirmed the constrained or unconstrained in vivo behaviour of the designs under study. This analysis also facilitated the interpretation of the kinematic behaviour of the prosthetic knees and may be of value in the evaluation of new designs. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1992, härtill 7 uppsatser.</p> / digitalisering@umu
4

Medicinos personalo (gydytojų radiologų ir radiologijos laborantų), informuotumo apie gaunamą pacientų apšvitą ir radiacinę saugą tyrimas / Privity research for medical personnel (radiologists and radiology technicians) about procurable patient‘s irradiance and radiation safety

Savičiūtė, Rasa 25 November 2010 (has links)
Darbo tikslas - nustatyti ir įvertinti asmens svaikatos priežiūros įstaigų medicinos personalo (gydytojų radiologų ir radiologijos laborantų) informuotumą apie pacientų gaunamą apšvitą ir radiacinę saugą Vilniaus mieste. Tyrimo objektas – gydytojai radiologai ir radiologijos laborantai. Tyrimo metu buvo apklausti 140 respondentų iš 15 asmens sveikatos priežiūros įstaigų. Viso buvo apklausta 35 gydytojai radiologai (iš jų 15 vyrų ir 20 moterų) ir 105 radiologijos laborantai (iš jų 4 vyrai ir 101 moteris), o tai atitinkamai sudarė 25,0% ir 75,0%. Apklaustųjų amžius svyruoja nuo 23 iki 71 metų (vidurkis 47,43). Tyrimo tikslui ir uždaviniams pasiekti panaudotas aprašomasis tyrimo tipas bei anketinės apklausos metodas. Statistinė duomenų analizė atlikta naudojant SPSS 13 programos versiją. Pateikiamas rodiklių pasiskirstymas absoliučiais skaičiais ir procentais, apskaičiuotas chi kvadratas (Chi-kv.). Sirtumas statistiškai reikšmingas kai pasikliovimo lygmuo p<0,05. Atlikta mokslinių straipsnių, sveikatos sistemos teisinės ir normatyvinės medžiagos ir t.t., analizė. Gautos šios išvados: įvertinus bendrą žinių lygį tarp apklaustų respondentų, galima teigti, kad gydytojai radiologai ir radiologijos laborantai pakankamai gerai žino radiacinės saugos principus bei apšvitos keliamą pavojų. Tačiau atliktas tyrimas taip pat parodė, kad jiems vis dar trūksta žinių kai kuriais specifiniais klausimais, pavyzdžiui tokiais kaip tipinės efektinės dozės gaunamos atliekant įvairias procedūras... [toliau žr. visą tekstą] / Main task – to estimate and evaluate medical personnel’s of health care (doctors of radiology and radiology assistants) informativeness about receivable irradiance towards patients and radiational safety in city of Vilnius. Object of research - doctors of radiology and radiology assistants. During this research 140 respondents were questioned from 15 health care institutions. Overall 35 radiologists were questioned (15 men and 20 women), 105 radiology assistants (4 men and 101 women) and that’s accordingly 20, 0% and 75, 0%. Age variance of the respondents is from 23 up to 71 years old (average of 47.43 years old). Descriptive research type and survey was used in order to achieve the goals of this research. Statistical data analysis was performed by using SPSS program, version 13. The given distribution of index is in natural numbers and in percentage, Chi-square is counted (Chi-sq). Statistically the difference is meaningful when the level of probability is p<0,05. The analysis of science articles, law normative materials, health care systems, etc. was accomplished. The conclusion: after the evaluation of knowledge of the respondents it is clear that, doctors of radiology and radiology assistants have enough knowledge about radiational safety and dangers of irradiance. The research also revealed that they do not have enough knowledge concerning the specific topics, for example the doses that are received during variable procedures, the dependence of the dose, the observation... [to full text]
5

Knee joint laxity and kinematics after anterior cruciate ligament rupture : roentgen stereophotogrammetric and clinical evaluation before and after treatment

Jonsson, Håkan January 1993 (has links)
Rupture of the anterior cruciate ligament (ACL) increases anterior-posterior (AP) laxity. The treatment aims to reduce or teach the patient to control this instability. Altered kinematics due to absent ligament function may result in knee arthrosis. This study evaluated the clinical and functional results of reconstructive surgery. Roentgen stereophotogrammetry (RSA) was used to analyse the stabilising effect of knee braces, reconstructive surgery and the kinematics of the knee with and without weight-bearing. The stability of the knees were assessed in 86 patients with ACL injuries before and/or after reconstructive surgery with the RSA technique and with the KT-1000 arthrometer The KT- 1000 (89 N) recorded smaller side to side differences than the RSA set-up without any correlation between the methods. The effect of three different braces on the AP and rotatory laxity was studied on patients with ACL injuries. The ECKO and the modified Lenox Hill reduced the instability with about one third. The SKB had no significant effect. None of the braces decreased the internal rotatory laxity but the Lenox Hill reduced the external rotatory laxity. Thirty-two patients with old ACL tears were treated with surgical reconstruction using the over the top technique (OTT) with or without augmentation. A small reduction in AP laxity was observed at the 6 month follow-up, The AP laxity was almost the same two years after as before surgery. No correlation was observed between the stability and knee function. Fifty-four patients with old unilateral anterior cruciate ligament injuries were randomised either to the over the top (OTT) or the isometric femoral tunnel position (ISO) at ACL reconstructive surgery. Seven of 24 (ISO) and 9 of 25 (OTT) had "normal" laxity two years after surgery. The patients operated with the ISO technique did not have better subjective knee function, muscle strength, functional performance or knee stability than patients operated with the OTT technique. The knee kinematics in patients with chronic unilateral ACL ruptures were examined during active extension in the supine position (13 patients) and during extension and weight-bearing (13 patients). The tibia displaced at an average 1.9 mm more anteriorly and 0.8 mm distally in the injured than in the intact knees during active extension. During extension and weightbearing the tibia was about 2 mm more posteriorly positioned than in the intact knee. The ACL rupture did not affect tibial rotations. Conclusions: The RSA recorded larger side to side differences in ACL injured and reconstructed patients than the KT-1000 arthrometer. Some knee braces are able to reduce AP laxity in ACL injured knees. No correlation was observed after surgery between knee laxity and functional scoring or tests. ACL reconstructions with isometric graft position on the femoral side did not offer any advantages compared to the over the top placement. Altered knee kinematics in the ACL injured knees were observed during knee extension with and without weight-bearing. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1993, härtill 6 uppsatser</p> / digitalisering@umu
6

Koncepce zabezpečení letiště Brno-Tuřany / Security Conception of Brno Turany Airport

Loučka, Karel January 2009 (has links)
In my thesis I address improvement of safety system of an international airport in Brno-Turany. I perform an analysis of current legislative safety needs and description of EU airport issues. I define particular safety requirements in reference to Brno-Turany airport. In the last part of my paper I suggest safety system that takes advantage of up to date technologies and recommendation to secure safety.
7

Signatur von Stossfronten in verschmelzenden und aktiven Galaxien. Optische/UV- und Roentgenbeobachtungen / Signatur of Shockfront in merging Systems and AGN. Optical/UV- and X-Ray Observations

Ansarifar , Hamidreza 30 July 2010 (has links)
No description available.

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