A Procedure for Application of Critical Path Method with Fuzzy Sets and Fuzzy Operations

Critical Path Method (CPM), which is used to schedule construction activitiesdepending to each other with network relationships, is deterministic in regards of the certaindurations assigned to activities for its execution and the results it produces in certain values.Unfortunately, construction activities are performed under uncertain conditions. Project riskscause variation in activity durations and in turn, the entire network is affected from uncertainty. In this context, activity durations are represented by fuzzy sets and CPM network calculations are performed by fuzzy operations through a new procedure developed in this study. In construction projects, the duration of an activity can not be proposed certainly inadvance. The predictions like "this activity can be completed most probably between 7 and 10days but perhaps it takes 15 days maximum and 5 days minimum depending on theconditions" are frequently made. Fuzzy numbers enable modeling such kind of uncertain predictions mathematically. Since the activity durations are represented by fuzzy numbers and network calculations are performed by fuzzy operations, the activity early/late start/finishtimes and the project completion time are calculated as fuzzy numbers by the proposed procedure. An example CPM application with fuzzy sets is also presented in the paper. The findings show that CPM is applicable with fuzzy sets and the developed procedure operates well for modeling the uncertainty in CPM calculations

A Case Study on the Use of Flexible Earth Retaining Structure In Instable Slopes

Recently new highway, motorway and railway projects take place in many developing countries within the aggressive infrastructure investment programme of governments. In rugged topography, engineers face the challenging problems of designing safe and cost effective cuts and fills for these projects especially under seismic loading and marginal stability conditions. Overall stability mechanism and safety of the cut generally controls the design decisions for the relevant section. In addition, because of the construction width limitations, in some mechanically stabilized earth wall projects sufficient width to accommodate the strip lengths of the retaining system cannot be provided. To eliminate all these problems, to minimize cut and backfill volumes and provide an innovative solution in such difficult terrains, soil nailing is implemented in the cut side together with the mechanically stabilized earth wall in the fill side together both are being flexible earth retaining structures. In addition, soil nails could be designed in such configuration and length that nails will also contribute to overall stability conditions of the cut slope. Furthermore, implementation of the system brings the advantage of reduction of both cut and fills volumes, therefore more cost effective and safer design. This paper presents application of this system in a recent case study, in Baku, Azerbaijan

Bio-inspired micro robots swimming in channels

Swimming micro robots that mimic micro organisms have a huge potential in biomedical applications such as opening clogged hard-to-reach arteries, targeted drug delivery and diagnostic operations. Typically, a micro swimmer that consists of a magnetic bead as its body, which is attached to a rigid helical tail, is actuated by a rotating external magnetic field and moved forward in the direction of the rotation in fluids. Understanding of hydrodynamic effects has utmost importance for modeling and prediction of the trajectory of the robot. In this work, a computational fluid dynamics (CFD) model is presented for the mm-long swimmer with the helical tail; the swimmer is used in our previous experiments on the effect of the confinement of the robot in a liquid filled channel. Forward velocity, fluid forces and torques on the micro swimmer are studied with respect to robot’s radial position in the channel and the number of waves on the helical tail. Forward velocities from the CFD model for the robots swimming near the wall agree reasonably well with experimental measurements

The Effects of Ten Weekly Plyometric Training of Judokas on Anaerobic Power

This study was conducted to determine the effects of ten weekly plyometric training on anaerobic power in judokas. 30 male judokas participated in the study and the subjects were divided into two groups as an experimental (15 male age = 21,40 ± 1,99) and control (15 male age = 21,53 ± 1,80) groups. Judo training programme was applied in both groups for 3 days / 90 minutes per week. Experimental and control group were made warm up exercises for 20 minutes. Both groups continued with the special preparatory period judo training program. After warm up exercises, experimental group judokas were made plyometric training consisting of 15 different movements for 20 minutes. Then they were allowed to continue the judo training. As the groups showed normal distribution, Paired Samples T-Test was applied for the significance between pre-test and post-test measurements of the groups. Independent Samples T-Test was used to analyze the difference between the test group and control group. The Independent Samples T-Test was used to analyze the difference between the experimental group and the control group. As a result of the plyometric training, when the pre-test and post-test differences of the physical measurement parameters for the experimental and control groups were compared, the mean values of back strength, anaerobic power and body fat percentage were found to be significant(p0.05). As a result, it is seen that the regular plyometric exercises increase the performance of anaerobic power to judokas. It can be said that putting plyometric training besides judo training has a positive effect for performance

Inhibitory effects of regorafenib, a multiple tyrosine kinase inhibitor, on corneal neovascularization

<b>AIM:</b>To evaluate the inhibitory effects of regorafenib (BAY 73-4506), a multikinase inhibitor, on corneal neovascularization (NV).<b>METHODS:</b>Thirty adult male Sprague-Dawley rats weighing 250-300 g, were used. Corneal NV was induced by NaOH in the left eyes of each rat. Following the establishment of alkali burn, the animals were randomized into five groups according to topical treatment. Group 1 (<i>n </i>= 6) received 0.9% NaCl, Group 2 (<i>n </i>= 6) received dimethyl sulfoxide, Group 3 (<i>n </i>= 6) received regorafenib 1 mg/mL, Group 4 (<i>n </i>=6) received bevacizumab 5 mg/mL and Group 5 (<i>n </i>= 6) received 0.1% dexamethasone phosphate. On the 7d, the corneal surface covered with neovascular vessels was measured on photographs as the percentage of the cornea’s total area using computer-imaging analysis. The corneas obtained from rats were semiquantitatively evaluated for caspase-3 and vascular endothelial growth factor by immunostaining.<b>RESULTS:</b>A statistically significant difference in the percent area of corneal NV was found among the groups (<i>P </i>&lt;0.001). Although the Group 5 had the smallest percent area of corneal NV, there was no difference among Groups 3, 4 and 5 (<i>P </i>&gt;0.005). There was a statistically significant difference among the groups in apoptotic cell density (<i>P </i>= 0.002). The staining intensity of vascular endothelial growth factor in the epithelial and endothelial layers of cornea was significantly different among the groups (<i>P </i>&lt;0.05). The staining intensity of epithelial and endothelial vascular endothelial growth factor was significantly weaker in Groups 3, 4 and 5 than in Groups 1 and 2.<b>CONCLUSION:</b> Topical administration of regorafenib 1 mg/mL is partly effective for preventing alkali-induced corneal NV in rats

Plasma total anti-oxidant capacity correlates inversely with the extent of acute appendicitis: a case control study

BACKGROUND: The role of free oxygen radicals in inflammatory conditions is well known. Free radicals cause lipid peroxidation of cellular membranes resulting in cell death. The purpose of this study was to investigate the levels of total anti-oxidant status (TAS), as a marker of anti-oxidant defense system and malondialdehyde (MDA), as a marker of oxidative stress, in the plasma of patients with acute appendicitis. METHODS: Fifty-one adult patients with a median age of 31 years who underwent operations with a preoperative diagnosis of acute appendicitis were included in this prospective study. Blood samples for C-reactive protein (CRP), MDA and TAS were collected preoperatively. Groups were compared by using the Mann-Whitney U test. RESULTS: There were 27 patients with acute phlagmenous appendicitis and 19 patients with advanced appendicitis (10 gangrenous and 9 perforated appendicitis), while 5 negative explorations were documented. No significant differences in WBC counts and MDA levels between groups were encountered. Plasma CRP was significantly higher in patients with perforated appendicitis, but not in the other groups. In advanced appendicitis group, TAS level was significantly lower than the other groups. On the other hand, plasma TAS level in acute phlagmenous appendicitis group was significantly higher. CONCLUSION: A decrease in plasma total anti-oxidant capacity might be a predictor of the progression of inflammation to the perforation in acute appendicitis

Are the single-step resection and primary anastomosis suitable for obstructıve colorectal patients in older cases?

Aim To investigate the efficacy and safety of the single-step surgery in elderly patients with obstructive colorectal cancer. Methods All patients who underwent single-step surgery and primary anastomosis for obstructive colorectal cancer in the period between January 2012 December 2017 were evaluated in this study. The patients were divided into two groups: younger than 65 (Group Young) and older than 65 (Group Old). Demographic data, American Society of Anesthesiologists scores (ASA) scores, comorbidities, preoperative albumin levels, type of surgery, postoperative morbidity and mortality, pathological stages, and overall survival rates were investigated. Results A total of 89 patients were included: 49 (54%) were older than 65 (Group Old). In Group Old, the mean age was 75 (65-97), of which 28 (58.3%) were males. There were 41 patients younger than 65 (Group Young) with the mean age of 52.6 (41-64 years of age), of which 21 (51.2%) were males. There was no difference between groups according to albumin level. There was no statistical difference between two groups according to tumour localization, pathological stage and type of surgery, as well as according to surgical complications. The median overall survival rate was 11 months in both groups (0-66) (p=0.320). Conclusion Meticulous preparation of older patients (correction of anaemia, electrolyte levels and pH ) paves the road for successful surgeries, including single-step resection and primary anastomosis

Influence of colonic mesenteric area on the number of lymph node retrieval for colon cancer: a prospective cohort study

Purpose The minimum harvested 12 lymph nodes (LNs) is regarded as the limit for accurate staging of nodal status in colorectal cancer patients. Besides the association of the lengths of resected intestinal segments and vascular pedicles, the mesocolic mesenteric area’s impact on LN count has not been studied. We aimed to evaluate the associations between metric variables, including the mesocolic mesentery area on the nodal harvest. Methods All consecutive patients who underwent elective colectomy with a curative intention for colon adenocarcinoma were prospectively included. The metric variables included the lengths of resected intestinal segments, vascular pedicle, and colonic mesenteric area. The variables influencing the LN count and the correlation between the total LN count and the specimens’ relevant metric measurements were analyzed. Results There were 46 patients with a median age of 64 years. The median count for total LNs was 22, and the LN positivity was 59.2%. There was an inadequate LN yield (0.05). There were significant positive correlations between total LN number and length of vascular pedicle and mesenteric area (r=0.576, P<0.001 and r=0.566, P<0.001). Conclusion The length of the vascular pedicle and mesenteric area were significantly correlated with total LN counts. Although there was no significant impact on the length of resected segments, the colonic mesenteric area can be used alone as a measure for the assessment of the nodal yield in colon cancer