793 research outputs found
Self-designing networks and structural influences on safety: Developing a theory on the relation between organizational design and safety in temporary organizations that operate in a dynamic environment
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178382.pdf (Publisher’s version ) (Open Access)Delft University of Technology, 01 juni 2017Promotores : Ale, B.J.M., Kramer, E.H.213 p
Qualitative study of the perfusion of the large intestine segment in the laparoscopic total mesorectal excision
No full textAbstract. The main aim of the research is to assess the perfusion of the large intestine segment with the JCG angiography in quality and quantity during the laparoscopic TME.
Materials and methods. The research work was carried out under the analysis of the results of fluorescence imaging of 28 patients diagnosed with the different levels of rectal adenocarcinoma and exposed to TME in laparoscopic way. The materials of the American hospital of Turkish Republic were used in the research work. The fluorescence density of the large intestine was measured and modeled with perfusion diagram beginning from the 30th second after being injected into the peripheral vein in the amount of 4.0 ml after dissolving of JCG (by being 0.25 mg/kg) in 10 ml physiological solution in the course of the operation. The fluorescence intensity of the large intestine segment was assed as weak, mean and high by using the indexes of fluorescence slope, T ½ max and time correlation (TR=1/2 T max/Tmax) over the diagram. The clinical factors were analyzed for study the integrity of anastomosis together.
Results. 17 of the patients were women, 10 of them were men and the age limit was 62.5. Laparoscopic TME was conducted on all of the patients. Complications associated with anastomosis were noted in 11.7% of the patients. The anastomotic attack in 2 patients, 1 anastomotic narrowness in 1 patient. TR>0.6 that is the quantity indexes of perfusion, tells about the lower perfusion. We consider the use of an intestinal fragment with low perfusion in creating of anastomoses as a great risk in respect of the anastomotic attack, anastomotic narrowness and necrosis of the anastomotic zone.
Conclusion: The use of quantity indexes as ½ T max and TR during the study of perfusion with JCG, assisted in finding the intestinal segment with weak perfusion
'She must be a very good novelist':Rereading E.H. Young (1880-1949)
No full textE.H. Young was a popular but reclusive English author who published eleven novels between 1910 and 1947. Beginning with the very successful William (1925). Young focussed on middle-class domesticity. The history of Young's subtly iconoclastic novels is, on the one hand, paradigmatic of women writers between the wars who explored the home, and. on the other, instructive about the complexity and limitations of concepts such as middlebrow, canon formation, taste, and modernity. Reading Young's novels and analyzing their publication hsitory and reception raise intriguing questions concerning the nature of reading pleasure and the continuing wide appeal of novels of the everyday.</p
Asfalt in de waterbouw
No full textDit document bevat de vijfde brochure van de Vereniging voor Bitumineuze Werken (VBW) getiteld "Asfalt in de waterbouw". De brochure bevat een achttal artikelen m.b.t. dit onderwerp: - Totstandkoming van de leidraad voor toepassing van asfalt in de waterbouw; voorgeschiedenis, opzet en toekomstig gebruik; door ir. E.H. Ebbens - Overzicht asfalttoepassingen in de waterbouw; door Prof. ir. J.F. Agema - Materiaaltechnologie; door H.J.A.J. Gruis - Ontwerpen van waterbouwkundige asfaltbekledingen; door ir. J.A. van Herpen - Resultaten uit recent onderzoek; door ir. H. Roos - Uitvoering van bitumineuze dijkbekledingen; door ir. G.L.M. Mulders - Bouwen en beheren; door ir. W. Bandsma - Beheer en onderhoud van waterkeringen; door ing. L.A. Philips
First-order phase transitions and giant magnetocaloric effect
No full textModern society relies on cooling technology for food safety, comfort and medical applications. The solid-state cooling technology known as magnetic refrigeration is one of the most promising techniques to replace the current vapor-compression cooling technology. To date, the search for suitable materials with a large magnetocaloric effect (MCE) for domestic applications of magnetic refrigeration is still in progress. This thesis describes a study focused on magnetocaloric materials that can be used in magnetic refrigerators operating at room temperature. Understanding of the phase transition in these materials is of great important to create better materials. As a refrigerator is expected to operate at rather high cycle frequencies, large thermal hysteresis (?Thys) at the magnetic phase transition is the main obstacle to use a material for applications. We have been successful in tuning ?Thys of MnFe(P1-xGex) and related compounds to very small values, while maintaining a large MCE in a large range of working temperatures. These low-cost materials can be used as refrigerants working at high frequencies. This brings the use of practical magnetic cooling a step closer. On the other hand, we have discovered a near room-temperature giant MCE in a new class of magnetic materials based on the intermetallic MnCoGe alloy. The mechanism of manipulating the first-order magnetic phase transition in the MnCoGe-based alloys opens up new possibilities for searching novel magnetic refrigerants for room-temperature applications.Radiation Radionuclides ReactorsApplied Science
Moment formation and giant magnetocaloric effects in hexagonal Mn-Fe-P-Si compounds
No full textLimited resources and the wish for improved prosperity call for efficient use of energy. The UN Advisory Group on Energy and Climate Change recommends a target of 40 % improved efficiency by 2030. Materials research can contribute significantly to reach this target. Magnetic refrigeration offers potential to achieve a 50 % higher energy-efficiency compared to vapor-compression refrigeration. This makes magnetic refrigeration a technology that attracts growing attention. Magnetic refrigeration is based on the magnetocaloric effect, i.e., the temperature change of a magnetic material upon the application or removal of a magnetic field in adiabatic conditions. Magnetocaloric materials play an important role in magnetic refrigeration. Giant magnetocaloric materials which are globally-abundant, non-toxic and can be industrially-mass-produced via a simple fabrication method are particularly attractive for magnetic refrigeration applications. Fe2P-based Mn-Fe-P-Si alloys can meet such requirements. The work presented in this thesis is a study of the magnetocaloric effect and related physical properties in the Mn-Fe-P-Si compounds. Some theoretical aspects of the magnetocaloric effect in general, and the origin of the first-order magneto-elastic transition which enhances the magnetocaloric effect in hexagonal Mn-Fe-P-Si compounds in particular are given in Chapter 2. In Chapter 3, a short review is presented of the experimental techniques and set-ups that have been employed for the sample preparation and the characterization of the physical properties of the Mn-Fe-P-Si compounds. Our efforts to optimize the magnetocaloric effect for refrigeration applications are presented in Chapter 4. We show that a giant magnetocaloric effect and a small thermal hysteresis in Mn-Fe-P-Si compounds of hexagonal Fe2P-type structure can be achieved simultaneously. Furthermore, the working temperature can be controlled over a large interval around room temperature by varying the Mn:Fe and P:Si ratios. In Chapter 5, we report on various types of transition found in (Mn,Fe)1.95P0.50Si0.50 when changing the Mn:Fe ratio. Interestingly, we observe a previously unknown first-order magneto-structural transition and a modified first-order magneto-elastic transition favorable for real refrigeration applications. Using high resolution neutron diffraction, x-ray diffraction and high-temperature magnetic-susceptibility measurements, and based on theoretical calculations, a first-order magneto-elastic transition from high-moment to low-moment in the Mn-Fe-P-Si compounds is presented in Chapter 6. This observation supports our proposal that the competition between moment formation and chemical bonding is at the core of giant magnetocaloric effect displayed in the class of hexagonal Fe2P-based materials with first-order magneto-elastic transition. The effect of the replacement of Fe by Mn on the magnetic moments is also discussed. Chapter 7 is devoted to the effects of P:Si ratio on the magnetic and structural properties of the Mn Fe P Si compounds. In chapter 8, we present magneto-elastic coupling in the Mn-Fe-P-Si compounds. Interestingly, hysteresis and magnetic entropy change are found to be correlated with discontinuous changes of the lattice parameters at the transition temperature. Small thermal hysteresis can be obtained while maintaining the giant magnetocaloric effect. A preliminary comparison of the magneto-elastic coupling and magnetocaloric effect for Mn-Fe-P-As/Ge/Si is also given.Radiation, Radionuclides & ReactorsApplied Science
Design of high-performance negative-feedback oscillators
No full textElectrical Engineering, Mathematics and Computer Scienc
Waterfront Rehabilitation Center in Galveston
No full textIt is a waterfront rehabilitation center design in Galveston, Houston, U.S, dealing with UTMB's campus expansion issues and surge protection plan.Delta InterventionArchitectureArchitecture and The Built Environmen
The Impact of Neoadjuvant Radiotherapy on Outcomes in Rectal Cancer Treatment
No full textPreoperative radiotherapy plays a crucial role in the treatment of rectal cancer. It is the only method proven to significantly reduce local recurrence rates. Radiotherapy contributes to improved treatment outcomes through three primary mechanisms: (1) downstaging the tumor to facilitate surgical resection, (2) reducing the risk of local recurrence by eradicating microscopic tumor foci in the operative field, and (3) increasing the likelihood of sphincter-preserving surgery, particularly in cases involving invasion of the levator ani or external anal sphincter musclesMaterials and MethodsIn this study, we analyzed 289 patients with rectal cancer, 80 (27.6%) of whom received preoperative radiotherapy. Of these, 30 patients (37.5%) underwent short-course radiotherapy and 50 (62.5%) underwent long-course radiotherapy. Among the long-course group, 22 patients (44%) were in the laparoscopic surgery group and 28 (56%) in the open surgery group. Long-course radiotherapy was delivered at 2 Gy per session over four weeks, while short-course radiotherapy consisted of 5 Gy per session over five days. Long-course results were assessed eight weeks post-radiotherapy.DiscussionShort-course radiotherapy was primarily administered in cases with suspected mesorectal lymph node metastases, followed by total mesorectal excision (TME) surgery within the subsequent week. In patients who received long-course radiotherapy, three distinct response patterns were observed: complete radiosensitivity, partial radiosensitivity, and radioresistance.In cases of complete radiosensitivity, the tumor underwent total regression; in partially radiosensitive cases, tumor size was reduced but not completely eliminated. In radioresistant cases, no significant change in tumor size was observed following radiotherapy. To quantitatively assess these effects, tumor regression rates were evaluated.ResultsFollowing long-course radiotherapy, among patients in the laparoscopic group, 4 (18.2%) demonstrated complete radiosensitivity, 15 (68.2%) exhibited partial radiosensitivity, and 3 (13.6%) were radioresistant. In the open surgery group, 5 (17.9%) patients showed complete radiosensitivity, 19 (67.9%) had partial radiosensitivity, and 4 (14.3%) were radioresistant (p = 0.998).Regarding tumor regression grading, in the laparoscopic group, Grade 1 regression was 19.1 ± 5.7%, Grade 2 was 51.1 ± 7.3%, Grade 3 was 17.0 ± 5.5%, and Grade 4 was 12.8 ± 4.9%. In the open surgery group, the respective values were 23.2 ± 5.6%, 44.6 ± 6.6%, 17.9 ± 5.1%, and 14.3 ± 4.7%.ConclusionLong-course radiotherapy demonstrated efficacy in reducing tumor size (including instances of complete tumor regression), minimizing local recurrence, and increasing the feasibility of surgical intervention. No statistically significant differences were observed between the laparoscopic and open surgery groups in terms of radiosensitivity or tumor regression rates (p > 0.05). Notably, Grade 2 regression was the most prevalent outcome, observed in 51.1 ± 7.3% of laparoscopic cases and 44.6 ± 6.6% of open surgery cases
The Impact of Neoadjuvant Radiotherapy on Outcomes in Rectal Cancer Treatment
No full textPreoperative radiotherapy plays a crucial role in the treatment of rectal cancer. It is the only method proven to significantly reduce local recurrence rates. Radiotherapy contributes to improved treatment outcomes through three primary mechanisms: (1) downstaging the tumor to facilitate surgical resection, (2) reducing the risk of local recurrence by eradicating microscopic tumor foci in the operative field, and (3) increasing the likelihood of sphincter-preserving surgery, particularly in cases involving invasion of the levator ani or external anal sphincter musclesMaterials and MethodsIn this study, we analyzed 289 patients with rectal cancer, 80 (27.6%) of whom received preoperative radiotherapy. Of these, 30 patients (37.5%) underwent short-course radiotherapy and 50 (62.5%) underwent long-course radiotherapy. Among the long-course group, 22 patients (44%) were in the laparoscopic surgery group and 28 (56%) in the open surgery group. Long-course radiotherapy was delivered at 2 Gy per session over four weeks, while short-course radiotherapy consisted of 5 Gy per session over five days. Long-course results were assessed eight weeks post-radiotherapy.DiscussionShort-course radiotherapy was primarily administered in cases with suspected mesorectal lymph node metastases, followed by total mesorectal excision (TME) surgery within the subsequent week. In patients who received long-course radiotherapy, three distinct response patterns were observed: complete radiosensitivity, partial radiosensitivity, and radioresistance.In cases of complete radiosensitivity, the tumor underwent total regression; in partially radiosensitive cases, tumor size was reduced but not completely eliminated. In radioresistant cases, no significant change in tumor size was observed following radiotherapy. To quantitatively assess these effects, tumor regression rates were evaluated.ResultsFollowing long-course radiotherapy, among patients in the laparoscopic group, 4 (18.2%) demonstrated complete radiosensitivity, 15 (68.2%) exhibited partial radiosensitivity, and 3 (13.6%) were radioresistant. In the open surgery group, 5 (17.9%) patients showed complete radiosensitivity, 19 (67.9%) had partial radiosensitivity, and 4 (14.3%) were radioresistant (p = 0.998).Regarding tumor regression grading, in the laparoscopic group, Grade 1 regression was 19.1 ± 5.7%, Grade 2 was 51.1 ± 7.3%, Grade 3 was 17.0 ± 5.5%, and Grade 4 was 12.8 ± 4.9%. In the open surgery group, the respective values were 23.2 ± 5.6%, 44.6 ± 6.6%, 17.9 ± 5.1%, and 14.3 ± 4.7%.ConclusionLong-course radiotherapy demonstrated efficacy in reducing tumor size (including instances of complete tumor regression), minimizing local recurrence, and increasing the feasibility of surgical intervention. No statistically significant differences were observed between the laparoscopic and open surgery groups in terms of radiosensitivity or tumor regression rates (p > 0.05). Notably, Grade 2 regression was the most prevalent outcome, observed in 51.1 ± 7.3% of laparoscopic cases and 44.6 ± 6.6% of open surgery cases
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