Monotonic and Cyclic Performance of Spun-Cast Ductile Iron Helical Tapered Piles

The performance of a novel piling system is investigated, which involves a spun-cast ductile iron (SCDI) tapered shaft fitted with a lower helical plate. It combines the efficiency of the tapered section, the competitive cost, effectiveness and durability of spun cast ductile iron with a rough surface and the construction advantages of helical piles. The system is installed using a fast, low vibration and reduced noise process. Seven instrumented piles including five SCDI tapered and two steel straight pipes were installed in sand using mechanical torque. The piles were subjected to cyclic and monotonic compression, uplift and lateral load tests. Different loading sequences were adopted to assess the effect of prior cyclic/monotonic loading on the piles’ performance. The installation torque was monitored and the resulting capacity-to-torque ratio was compared to the literature reported values. The compaction of the previously disturbed sand from the helix penetration due to the pile taper resulted in superior compressive behavior of the proposed system compared to the straight shaft piles. The tapered piles exhibited higher stiffness at lower displacements compared to the straight shafted piles and the helix increased their uplift resistance. In addition, tapered shafts enhanced the lateral stiffness and the helix provided fixation due to the passive bearing pressures on the helix surfaces, which further improved the lateral performance of the short helical piles. A three dimensional finite element model was established and calibrated using the experimental data. The model was then used to simulate the response of SCDI piles with different configurations when subjected to different loading conditions including axial and lateral as well as combined moment-horizontal loads. Under cyclic loading, the tapered helical piles exhibited better compressive performance while the straight shaft helical piles performed better in uplift loading. The proposed system stiffness remained practically unchanged through the cyclic lateral loading applied in the current study. The monotonic performance of the tapered helical piles in clay was numerically simulated. The results showed an increase in axial and lateral capacity and stiffness of the tapered piles over the straight shaft ones, with greater uplift-to-compressive capacity ratio than in sand

Comparison of The Functional and Oncological Outcomes of the Sub-trigonal Versus Conventional Robotic Radical Prostatectomy for Prostate Cancer

6.1. Background The subtrigonal approach for robotic assisted radical prostatectomy was first described in 2010 as the most anatomically preserving technique, in which the prostate can be completely removed through the Douglas pouch. This technique was introduced in the Urology Department of Tuebingen University Hospital in June 2013 after many years of performing the conventional transperitoneal robotic prostatectomy, however few data is available regarding its outcome. 6.2. Objectives The aim of this study is to compare the functional and oncological outcomes of subtrigonal approach versus the conventional approach for robotic radical prostatctomy 6.3. Methods Consecutive groups of patients who underwent TPRP (n=126) from 01/2012 to 05/2013, and those who switched and underwent STRP (n=62) from 01/2014 to 01/2015 were compared;. Functional outcomes were evaluated using ICIQ and IIEF of both groups by questionnaire and telephone protocols. Oncological outcomes were assessed regarding positive surgical margins and biochemical recurrence free survival (PSA ≥ 0.02 ng/ml) using the Kaplan Meier curve. Postoperative complications were classified using the Clavien-Dindo system. Statistical analysis was performed using the jmp v.12 software®. Mann-Whitney-U and Pearson x2 tests were employed to compare the continuous and categorical variables, respectively. The Kaplan Meier curve was applied to present the survival data 6.4. Results The median age and follow-up time in the TPRP and STRP groups were 64 and 62.5 years and 34 and nine months, respectively. Within 7 days of catheter removal, 37/93 patients (40%) in group A were continent compared to 23/53 (43%) in group B (p-value = 0.67). At 3, 6 and 12-month intervals, the continence recovery rates were 71%, 73% and 87% in group A versus 76%, 89% and 96% in group B. The p-values were 0.55, 0.02 and 0.054, respectively. 15 and 7 patients in group A and B, respectively, underwent bilateral nerve sparing surgery (NS). In group A, 2/15 (13%) could achieve enough erection for penetration versus 3/7 (43%) in group B; (p-value = 0.13). The overall positive surgical margin (PSM) rate was 16% in group A versus 8% in group B (p-value = 0.11). According to the pathological stage, PSM rates in pT2, pT3a and pT3b were 7.2%, 53% and 55.6% in group A compared to 2.2%, 11% and 60% in group B, respectively (p-values = 0.19, 0.03 and 0.87). PSM in pT3a was significantly lower in group B. When comparing the PSM rate at the prostatic apex, it was 9.8% in group A versus 1.6% in group B; with a significant difference (p-value = 0.02). The BCR 1y-free survival was 91% in group A versus 94% in group B (Log-rank p-value = 0.57). 6.5. Conclusion The anatomical preservative sub-trigonal approach for RARP increases the post-operative continence recoverability. Our results approved the oncological safety of this technique even in locally advanced cases. Sub-trigonal approach displayed reduction of PSM especially at the apex and in tumors with extra- capsular extension. Prospective randomized studies including bigger cohorts of patients with longer follow up are mandatory to confirm these results

NUMERICAL INVESTIGATION OF THE UNDRAINED PULLOUT CAPACITY OF ANCHORS EMBEDDED IN CLAY

Two dimensional plane strain finite element analysis has been conducted to simulate the pullout behavior of vertical anchors of different shapes when embedded in clay. These shapes include plate anchors, anchors with irregular base shapes, and plate anchors with rectangular openings. For the first two types, the effects on the pullout behavior of embedment depth, overburden pressure, soil-anchor interface strength, anchor thickness, base shape and size, rate of clay strength increase, anchor and load inclination, point of load application and soil disturbance due to anchor installation were all studied. The anchor pullout capacity is shown to be strongly affected by embedment depth, overburden pressure, load inclination angle, rate of clay shear strength increase per depth and soil-anchor interface strength. Similarly, disturbed clay strengths adjacent to the anchor following installation were found to cause a significant reduction in the anchor capacity. The effect of other parameters, such as the anchor thickness and the load application point, were found to be less significant. Among the studied base shapes, the triangular based anchors were found to have the greatest vertical pullout resistance, while the lateral pullout was not significantly improved for any of the studied shapes. This form of anchor was also shown to be the most efficient shape in terms of cross-sectional steel area compared to the pullout capacity. Normal and inclined load vertical and horizontal plate anchors with rectangular openings were studied at different embedment depths for no-breakaway and immediate breakaway conditions. For this anchor type, the embedment depth showed a significant effect on the efficiency for fully bonded conditions, but only a negligible effect for immediate breakaway conditions. The results suggest the feasibility of this anchor type as an alternative to regular plate anchors, especially for shallow offshore conditions, where limitations on cranage capacity exist

Problemas de durabilidad de los materiales de construcción arqueológicos en ambientes acuosos y subaéreos, con aplicaciones a la restauración y conservación en Egipto y Sudán.

The main objective of the study was to identify and assess the conservation problems of the building materials of each case study and compare the aggressive impacts of each environment on the sustainability of the construction materials. Carefully, the construction materials (limestone, sandy limestone, sandstone, lime mortars, gypsum, hydraulic lime mortar/roman mortar) were selected from different archaeological sites with different environmental conditions in Egypt and Sudan (desert: Sahure?s pyramid and pyramids of Meroe; urban/agricultural: Nero/Ramses II Temple; coastal: Anfushi?s Necropolis; and fluvial: Abaton/Osiris Temple). To achieve this goal, field observations, analytical (X-ray diffraction, X-ray fluorescence, Raman spectroscopy, UV-Vis spectrometry), microscopic (binocular microscope, polarizing microscope and scanning electron microscope), mapping (AutoCAD, ArcMap 10.8, SeaDAS, QGIS), and physical and mechanical testing investigations were carried out. Furthermore, open-access satellite lenses were used for the detection and assessment of the archaeological sites and their risks, and, the deterioration patterns of each case study were recorded through decay mappings. Finally, to preserve the lime mortar surfaces, a newly synthesized nanomaterial of SiO2-TiO2 NPs/TEOS was applied and tested. The results showed the severity of each factor on the construction materials. In this sense, Sahure?s pyramid was affected mainly by climatic and environmental factors, earthquakes and the inner composition of the building materials. Nero/Ramses II Temple showed its susceptivity mainly from the salt attack which came from the contaminated sources of water around the temple. Water intrusion, earthquakes, storms, and heavy rains factors attacked Anfushi?s Necropolis severely. Abaton/Osiris Temple was decayed because of Nile water fluctuations impact and the inner weakness of the temple sandstones. In Sudan, the pyramids of Meroe were damaged because of the sand dunes and wind forces, in addition to the flooding risks. Finally, and concerning to the heritage conservation, the research exhibited the efficacy of the multifunctional 3% and 5% SiO2-TiO2 NPs/TEOS in the consolidation and improvement of the physical and mechanical ancient lime mortars

ENHANCEMENT OF FILTRATE LOSS CONTROL USING SMART NANO-WBM TO MINIMIZA TIGHT SPOTS PROBLEMS IN WELLBORE

The objective of this project is to use a smart nano drilling fluid which is prepared using nano size bentonite clay which has an enhancement of its rheological properties of the mud especially quick plastering of the wall of the wellbore based on the efficient filtrate loss control into the high porous and high permeable formation. The appreciable enhancement in the filtrate loss control properties is expected by using thus smart nano drilling fluid as compared to the conventional water based mu

The Unified Methodology for Application and Database Development UMADD (Using “abbCode” Framework)

The study describes a new methodology for architecting software using a new developed tool in a way that make development processes easier, increase productivity and reducing bugs and potential errors avoiding overheads.

Opportunities and challenges in personalized MOOC experience

To provide MOOC participants with efficient learning resources and feedback according to the unique needs of each learner is obvious a greater challenge. In this paper, we describe the top five challenges that have the power to hinder the overall personalize MOOC experience. In addition to that, we suggest new opportunities considering individual differences in order to support personalized MOOC experienc

A systematic literature review

Bahaa, A., Abdelaziz, A., Sayed, A., Elfangary, L., & Fahmy, H. (2021). Monitoring real time security attacks for iot systems using devsecops: A systematic literature review. Information (Switzerland), 12(4), 1-23. [154]. https://doi.org/10.3390/info12040154In many enterprises and the private sector, the Internet of Things (IoT) has spread globally. The growing number of different devices connected to the IoT and their various protocols have contributed to the increasing number of attacks, such as denial-of-service (DoS) and remote-to-local (R2L) ones. There are several approaches and techniques that can be used to construct attack detection models, such as machine learning, data mining, and statistical analysis. Nowadays, this technique is commonly used because it can provide precise analysis and results. Therefore, we decided to study the previous literature on the detection of IoT attacks and machine learning in order to understand the process of creating detection models. We also evaluated various datasets used for the models, IoT attack types, independent variables used for the models, evaluation metrics for assessment of models, and monitoring infrastructure using DevSecOps pipelines. We found 49 primary studies, and the detection models were developed using seven different types of machine learning techniques. Most primary studies used IoT device testbed datasets, and others used public datasets such as NSL-KDD and UNSW-NB15. When it comes to measuring the efficiency of models, both numerical and graphical measures are commonly used. Most IoT attacks occur at the network layer according to the literature. If the detection models applied DevSecOps pipelines in development processes for IoT devices, they were more secure. From the results of this paper, we found that machine learning techniques can detect IoT attacks, but there are a few issues in the design of detection models. We also recommend the continued use of hybrid frameworks for the improved detection of IoT attacks, advanced monitoring infrastructure configurations using methods based on software pipelines, and the use of machine learning techniques for advanced supervision and monitoring.publishersversionpublishe