152 research outputs found
Improving Building Information Modeling (BIM) Implementation throughout the Construction Industry
Building Information Modeling (BIM) is extensively used in the construction industry due to its benefits throughout the Project Life Cycle (PLC). BIM can simulate buildings throughout PLC, detect and resolve problems, and improve building visualization that contributes to the representation of actual project details in the construction stage. BIM contributes to project management promotion by detecting problems that lead to conflicts, cost overruns, and time delays. This work aims to implement an effective BIM for the Iraqi construction projects’ life cycle. The methodology used is a literature review to collect the most important factors contributing to the success of BIM implementation, interview the team of the Central Bank of Iraq (CBI) building, and strive to improve the BEP of the CBI building. However, previous studies indicate collaborative work and communications enhance effective BIM implementation, which can improve BIM use by applying a BEP and an AEC (UK) BIM protocol that leads to positive BIM impact. BEP comprises important information and goals related to the intended project, including the BIM collaborative process (process map), information exchange requirements, BIM data management, BIM model management, and quality control, which are considered essential for enhancing BIM collaboration during PLC. This paper concludes that implementing BIM effectively requires overcoming obstacles faced by Iraqi construction projects. Effective BIM implementation requires improving collaboration and communication throughout the construction process, which could be achieved by depending on the BIM Execution Planning Guide(BEP Guide) and the AEC (UK) BIM Protocol 2012 V2.
Proposing an Approximate Mathematical Model to Conduct the Calculations of Radioactive Cs137 in the Plant
This study aims at calculating theoretically the radioactive of cesium Cs 137 in the plant of Nineveh governorate by selecting 50 positions as samples of the study. The calculations are carried out by constructing a mathematical model that determines theoretically the radioactive of cesium Cs 137in the plant. In this paper, the main features and process of mathematical modeling is stated and used clearly in the process of constructing the mathematical model which conducts the determination of the radioactive of cesium Cs 137. The values calculated by the proposed mathematical model show that Cs 137 radioactive range is: (1.0832 in (A42 & A42) – 4.1020 in (A48)) Bq/kg in plant. These calculations are conducted by comparing the results, obtained from the constructed model, with the values of other references. The result of this comparison shows good agreement with other literatures
Enhancing Oil Removal from Water using Ferric Oxide Nanoparticles Doped Carbon Nanotubes Adsorbents
Oil contaminated water is one of the challenges in water resources management. It is crucial to remove the oil droplets from water in order to meet the discharge regulations set by the environmental authorities. Carbon nanotubes (CNTs) have generated a lot of attention as a new type of adsorbent due to their exceptionally high adsorption capacity for oil–water separation. The high hydrophobicity of CNTs makes them good candidates to enhance the de-oiling process from wastewater. In this study, we have reported the synthesis and evaluation of novel iron-oxide/CNTs nanocomposites for oil–water separation. The CNTs were doped with different loadings of iron oxide nanoparticles using a wet impregnation technique. The synthesized nanocomposite nanomaterials were characterized using field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (TEM), Brunauer, Emmett and Teller (BET) technique, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The effect of adsorption parameters, including, adsorbent dosage, contact time, and agitation speed on the oil removal efficiency were optimized using batch experiments. The sorption capacities of doped CNTs were found to be greater than 7 g/g for gasoline oil. The doped CNTs reached maximum sorption capacity after only 15 min providing one of the fastest minimum contact times reported of all oil sorbent materials. The loading of Fe2O3 nanoparticles on the negative surface of CNT decreases the negative sign and magnitude of the zeta potential by overcoming the repulsive effects of the electrical double layers to allow the finely sized oil droplets to form larger droplets through coalescence. Therefore increasing percentage of the Fe2O3 on the surface of CNT increased the removal of the emulsified oil from the water
The effect of Valsalva maneuver on diastolic filling indices in patients with essential hypertension.
Background: Left ventricular hypertrophy and diastolic dysfunction are considered to be an important risk factor for cardiovascular morbidity and mortality in asymptomatic hypertensive
patients. At the bedside, left ventricular geometric remodeling and diastolic dysfunction in hypertension can not be diagnosed without echocardiography which is a useful adjunct to the medical history, physical examination, ECG, and chest radiography. Hence, it provides an opportunity for good management and prognosis of what appears to be preclinical hypertensive complication.
Subjects and Methods: 127 subjects with essential hypertension of either sex attending echo unit were subjected to medical history, clinical examination, physical measurements, ECG, M-mode and Doppler echocardiography. They were classified as 46 treated hypertensives where they were on regular antihypertensive medication, and 81 untreated hypertensive patients. In addition, they were sex and age matched to 39 healthy subjects who served as control group.
Results: The results of this study revealed that hypertensive patients especially those with stage II hypertension were prone to develop left ventricular hypertrophy (LVH) of concentric geometric pattern and diastolic dysfunction. However, small percentage of those patients found to have diastolic dysfunction despite they were without LVH. In addition, Doppler echocardiography clarify that hypertensives with abnormal transmitral inflow profile; of left ventricular impaired relaxation pattern suffered left ventricular systolic dysfunction. Moreover, in this study there was no evidence of pseudonormal transmitral inflow filling pattern which is excluded after Valsalva maneuver.
Conclusion: There is a strong association between left ventricular hypertrophy and diastolic dysfunction which was more common in patients with stage II hypertension. However, left
ventricular diastolic dysfunction is usually follows left ventricular hypertrophy, but it still may proceed especially in those patients with left ventricular hypertrophy (LVH) of concentric geometric pattern. In addition, left ventricle diastolic dysfunction is not necessary coincide with the development of systolic dysfunction, namely normal ejection fraction and fractional shortening
Aberrant right subclavian artery in a cadaver: a case report of an aortic arch anomaly
In early embryogenesis, aortic anomalies occur as a consequence of disorders in the development of the primitive aortic arches system. Aberrant right subclavian artery, also known as arteria lusoria, is one of the important congenital anomalies of the aortic arch, in which the right subclavian artery arises from the arch of aorta instead of the brachiocephalic trunk. During routine dissection of a female cadaver, we observed retro-oesophageal aberrant right subclavian artery arising as the fourth branch from the aortic arch. In this case, the brachiocephalic trunk was absent. Early detection of aortic arch anomalies through diagnostic interventions is helpful to avoid complications during surgical procedures
Neoadjuvant Chemotherapy for Intrahepatic, Perihilar, and Distal Cholangiocarcinoma:a National Population-Based Comparative Cohort Study
IntroductionData supporting the utilization of neoadjuvant chemotherapy (NAC) in patients receiving resection for cholangiocarcinoma (CCA) remains uncertain. We aimed to determine whether NAC followed by resection improves long-term survival in intrahepatic (iCCA), perihilar (hCCA), and distal (dCCA) cholangiocarcinoma, analyzed separately.MethodsPatients undergoing surgery for iCCA, hCCA, and dCCA, receiving either none, NAC, or adjuvant chemotherapy (AC) from 2010 to 2016 were identified from the National Cancer Database (NCDB). Cox regression was performed to account for selection bias and to assess the impact of surgery alone (SA) versus either NAC or AC on overall survival (OS).ResultsThere were 9411 patients undergoing surgery for iCCA (n = 3772, 39.5%), hCCA (n = 1879, 20%), and dCCA (n = 3760, 40%). Of these, 10.6% (n = 399), 6.5% (n = 123), and 7.2% (n = 271) with iCCA, hCCA, and dCCA received NAC, respectively. On adjusted analyses, patients receiving NAC followed by surgery had significantly improved OS, compared to SA for iCCA (HR 0.75, CI95% 0.64-0.88, p < 0.001), hCCA (HR 0.72, CI95% 0.54-0.97, p = 0.033), and for dCCA (HR 0.65, CI95% 0.53-0.78, p < 0.001). However, sensitivity analyses demonstrated no differences in OS between NACs, followed by surgery or AC after surgery in iCCA (HR 1.19, CI95% 0.99-1.45, p = 0.068), hCCA (HR 0.83 CI95% 0.59-1.19, p = 0.311), and dCCA (HR 1.13 CI95% 0.91-1.41, p = 0.264).ConclusionsThis study associated NAC with increased OS for all CCA subtypes, even in patients with margin-negative and node-negative disease; however, no differences were found between NAC and AC. Our results highlight that a careful and interdisciplinary evaluation should be sought to consider NAC in CCA and warrant the need of larger studies to provide robust recommendation
International multicenter propensity score matched study on laparoscopic versus open left lateral sectionectomy
Background: Despite a lack of high-level evidence, current guidelines recommend laparoscopic left lateral sectionectomy (LLLS) as the routine approach over open LLS (OLLS). Randomized studies and propensity score matched studies on LLLS vs OLLS for all indications, including malignancy, are lacking.Methods: This international multicenter propensity score matched retrospective cohort study included consecutive patients undergoing LLLS or OLLS in six centers from three European countries (January 2000-December 2016). Propensity scores were calculated based on nine preoperative variables and LLLS and OLLS were matched in a 1:1 ratio. Short-term operative outcomes were compared using paired tests.Results: A total of 560 patients were included. Out of 200 LLLS, 139 could be matched to 139 OLLS. After matching, baseline characteristics were well balanced. LLLS was associated with shorter operative time (144 (110-200) vs 199 (138-283) minutes, P < 0.001), less blood loss (100 (50-300) vs 350 (100-750) mL, P = 0.005) and a 3-day shorter postoperative hospital stay (4 (3-7) vs 7 (5-9) days, P < 0.001).Conclusion: This international multicenter propensity score matched study confirms the superiority of LLLS over OLLS based on shorter postoperative hospital stay, operative time, and less blood loss thus validating current guideline advice.</p
Learning Curves of Minimally Invasive Distal Pancreatectomy in Experienced Pancreatic Centers
IMPORTANCE Understanding the learning curve of a new complex surgical technique helps to reduce potential patient harm. Current series on the learning curve of minimally invasive distal pancreatectomy (MIDP) are mostly small, single-center series, thus providing limited data.OBJECTIVE To evaluate the length of pooled learning curves of MIDP in experienced centers.DESIGN, SETTING, AND PARTICIPANTS This international, multicenter, retrospective cohort study included MIDP procedures performed from January 1, 2006, through June 30, 2019, in 26 European centers from 8 countries that each performed more than 15 distal pancreatectomies annually, with an overall experience exceeding 50 MIDP procedures. Consecutive patients who underwent elective laparoscopic or robotic distal pancreatectomy for all indications were included. Data were analyzed between September 1, 2021, and May 1, 2022.EXPOSURES The learning curve for MIDP was estimated by pooling data from all centers.MAIN OUTCOMES AND MEASURES The learning curvewas assessed for the primary textbook outcome (TBO), which is a composite measure that reflects optimal outcome, and for surgical mastery. Generalized additive models and a 2-piece linear model with a break point were used to estimate the learning curve length of MIDP. Case mix-expected probabilities were plotted and compared with observed outcomes to assess the association of changing case mix with outcomes. The learning curve also was assessed for the secondary outcomes of operation time, intraoperative blood loss, conversion to open rate, and postoperative pancreatic fistula grade B/C.RESULTS From a total of 2610 MIDP procedures, the learning curve analysis was conducted on 2041 procedures (mean [SD] patient age, 58 [15.3] years; among 2040 with reported sex, 1249 were female [61.2%] and 791 male [38.8%]). The 2-piece model showed an increase and eventually a break point for TBO at 85 procedures (95% CI, 13-157 procedures), with a plateau TBO rate at 70%. The learning-associated loss of TBO rate was estimated at 3.3%. For conversion, a break point was estimated at 40 procedures (95% CI, 11-68 procedures); for operation time, at 56 procedures (95% CI, 35-77 procedures); and for intraoperative blood loss, at 71 procedures (95% CI, 28-114 procedures). For postoperative pancreatic fistula, no break point could be estimated.CONCLUSION AND RELEVANCE In experienced international centers, the learning curve length of MIDP for TBO was considerable with 85 procedures. These findings suggest that although learning curves for conversion, operation time, and intraoperative blood loss are completed earlier, extensive experience may be needed to master the learning curve of MIDP
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