Combined use of geocell reinforcement and rubber–soil mixtures to improve performance of buried pipes

2012 ◽  
Vol 34 ◽  
pp. 116-130 ◽  
Author(s):  
Gh. Tavakoli Mehrjardi ◽  
S.N. Moghaddas Tafreshi ◽  
A.R. Dawson
2018 ◽  
Vol 9 (2) ◽  
pp. 86 ◽  
Author(s):  
Mohammed Yousif Fattah ◽  
Waqed Hameed Hassan ◽  
Sajjad E. Rasheed

2018 ◽  
Vol 9 (1) ◽  
pp. 22-41 ◽  
Author(s):  
Mohammed Yousif Fattah ◽  
Waqed Hammed Hassan ◽  
Sajjad Emad Rasheed

The present article constitutes an experimental investigation of the behavior of buried PVC pipes. A number of laboratory experiments were conducted using PVC pipes which were buried in a medium sand layer, below a subbase layer, reinforced with geocells. They were subject to repeated dynamic load amplitudes of 0.5 and 1 ton and loading frequencies of 0.5, 1 and 2 Hz, to study the effects of the geocell reinforcement layer, in terms of the amount of stress reaching the pipe crown and the vibration of the pipe. A 3D numerical model was also developed to investigate the performance of the geocell above the buried pipe. The predicted characteristics of the buried pipes were validated using the experimental data. The results showed that geocell reinforcement decreases both crown vibration by 35%, and the vertical pressure reaching the pipe by 41%. The numerical models have a good fit with the experimental work results, both confirming that geocell reinforcement has a significant role to play regarding increasing the safety of pipes.


2014 ◽  
Vol 45 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Robert J. Calin-Jageman ◽  
Tracy L. Caldwell

A recent series of experiments suggests that fostering superstitions can substantially improve performance on a variety of motor and cognitive tasks ( Damisch, Stoberock, & Mussweiler, 2010 ). We conducted two high-powered and precise replications of one of these experiments, examining if telling participants they had a lucky golf ball could improve their performance on a 10-shot golf task relative to controls. We found that the effect of superstition on performance is elusive: Participants told they had a lucky ball performed almost identically to controls. Our failure to replicate the target study was not due to lack of impact, lack of statistical power, differences in task difficulty, nor differences in participant belief in luck. A meta-analysis indicates significant heterogeneity in the effect of superstition on performance. This could be due to an unknown moderator, but no effect was observed among the studies with the strongest research designs (e.g., high power, a priori sampling plan).


2009 ◽  
Vol 29 (04) ◽  
pp. 376-380 ◽  
Author(s):  
D. Capodanno ◽  
D. J. Angiolillo

SummaryDespite the clinical benefit associated with the combined use of aspirin and clopidogrel in patients with acute coronary syndrome or those undergoing percutaneous coronary intervention, a considerable interindividual variability in response to these drugs have been consistently reported. There is a growing interest on applying platelet functional tests with the goal of identifying patients at increased risk of recurrent ischaemic events and potentially tailoring antiplatelet treatment regimens.This manuscript will review the state of the art on the most commonly available platelet functional tests, describing their advantages and disadvantages and exploring their applicability in clinical practice.


1997 ◽  
Vol 36 (08) ◽  
pp. 282-288 ◽  
Author(s):  
T. Atasever ◽  
A. Özdemir ◽  
I. Öznur ◽  
N. I. Karabacak ◽  
N. Gökçora ◽  
...  

Summary Aim: Our goal was to determine the clinical usefulness of TI-201 to identify breast cancer in patients with suspicious breast lesions on clinical examination, and/or abnormal radiologic (mammography and/or ultrasonography) findings. Methods: TI-201 scintigraphy were performed in sixty-eight patients with 70 breast abnormalities (51 palpable, 19 nonpalpable) and compared with mammography and ultrasonography (US). Early (15 min) and late (3 h) images of the breasts were obtained following the injection of 111 MBq (3 mCi) of TI-201. Visual and semiquantitative interpretation was performed. Results: Final diagnosis confirmed 52 malignant breast lesions and 18 benign conditions. TI-201 visualized 47 of 52 (90%) overall malignant lesions. Thirty-eight of 40 (95%) palpable and 9 of 12 (75%) nonpalpable breast cancers were detected by TI-201 scintigraphy. The smallest mass lesion detected by TI-201 measured 1.5x1.0 cm. Eleven breast lesions were interpreted as indeterminate by mammography and/or sonography. TI-201 scintigraphy excluded malignancy in 7 of 8 (88%) patients with benign breast lesions interpreted as indeterminate. Five of the 18 (28%) benign breast lesions showed TI-201 uptake. None of the fibroadenoma and fibrocystic changes accumulated TI-201. TI-201 scintigraphy, mammography and ultrasonography showed 90%, 92%, 85% overall sensitivity and 72%, 56%, 61% overall specificity respectively. Twenty-one of the 28 (75%) axillary nodal metastatic sites were also detected by TI-201. In malignant and benign lesions, early and late lesion/contralateral normal side (L/N) ratios were 1.58 ± 0.38 (mean ± SD) and 1.48 ± 0.32 (p >0.05), 1.87 ± 0.65 and 1.34 ± 0.20 (p<0.05) respectively. The mean early and late L/N ratios of malignant and benign groups did not show statistical difference (p>0.05). Conclusion: Overall, TI-201 scintigraphy was the most specific of the three methods and yielded favourable results in palpable breast cancers, while it showed lower sensitivity in nonpalpable cancers and axillary metastases. Combined use of TI-201 scintigraphy with mammography and US seems to be useful in difficult cases, such as dense breasts and indeterminate breast lesions.


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