127 research outputs found

    BIM execution process of construction companies for building projects

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    Building Information Modeling (BIM) has been an emerging concept in architecture, engineering and construction (AEC) industry with a vast amount of promising benefits to construction projects. Implementation of BIM, however, requires comprehensive research and strategic planning. Industry-wide and organizational implementation guidelines and standards have been published around the world either to encourage organizations to adopt BIM or to present the minimum requirements to be followed where BIM implementation is a statutory obligation. In contrast, governments or organizations in several countries such as Turkey have not mandated BIM implementation and provide no guidance. Organizations in these countries which plan to adopt BIM processes are forced to develop their own implementation plans. The purpose of this study is to provide guidance in BIM implementation for construction companies in countries where BIM implementation has not been mandated particularly during the construction phase of the building projects. 23 BIM standards and guidelines covering the BIM execution process have been reviewed. Topics that need to be addressed by BIM implementation plans have been identified and categorized under four headings. A case study of BIM implementation at a large construction company that focuses on conducting quantity takeoff and cost estimation is presented, and unique challenges of BIM implementation in Turkish AEC industry are discussed

    Single-mode lasing from a single 7 nm thick monolayer of colloidal quantum wells in a monolithic microcavity

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    In this work, we report the first account of monolithically-fabricated vertical cavity surface emitting lasers (VCSELs) of densely-packed, orientation-controlled, atomically flat colloidal quantum wells (CQWs) using a self-assembly method and demonstrate single-mode lasing from a record thin colloidal gain medium with a film thickness of 7 nm under femtosecond optical excitation. We used specially engineered CQWs to demonstrate these hybrid CQW-VCSELs consisting of only a few layers to a single monolayer of CQWs and achieved the lasing from these thin gain media by thoroughly modeling and implementing a vertical cavity consisting of distributed Bragg reflectors with an additional dielectric layer for mode tuning. Accurate spectral and spatial alignment of the cavity mode with the CQW films was secured with the help of full electromagnetic computations. While overcoming the long-pending problem of limited electrical conductivity in thicker colloidal films, such ultra-thin colloidal gain media can help enabling fully electrically-driven colloidal lasers

    Hyperbolic Centroid Calculations for Text Classification

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    A new development in NLP is the construction of hyperbolic word embeddings. As opposed to their Euclidean counterparts, hyperbolic embeddings are represented not by vectors, but by points in hyperbolic space. This makes the most common basic scheme for constructing document representations, namely the averaging of word vectors, meaningless in the hyperbolic setting. We reinterpret the vector mean as the centroid of the points represented by the vectors, and investigate various hyperbolic centroid schemes and their effectiveness at text classification

    Development of an optimum proliferation medium via the graph kernel statistical analysis method for genetically stable in vitro propagation of endemic Thymus cilicicus (Turkey)

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    Thymus cilicicus is an endemic Eastern Mediterranean element that has aromatic-medicinal properties. Its natural population spreads across gravelly ground and open rocky areas of South and Southwest Anatolia. The current study on in vitro propagation of T. cilicicus focused deeply on environmental applications such as the development of an optimum medium composition for efficient and genetically stable micropropagation and improved preservation procedures for long-time conservation of elite germplasms for further studies. For this purpose, MS and OM media were used individually and in combination with cytokinins, charcoal, AgNO3, Fe-EDDHA, and H3BO3. The raw data were statistically analyzed via the graph kernel method to optimize the nonlinear relationship between all parameters. The optimal proliferation medium for T. cilicicus was OM supplemented with a combination of 10 g L-1 charcoal and 1 mg L-1 KIN and the calculated averages of the best regeneration rate, the best shoot number and the best shoot length were 96.89%, 3 and 1.24 respectively on this medium. The determination of genetic stability of in vitro grown plants on the optimum medium compositions obtained by the graph kernel method was carried out with the use of the ISSR-PCR technique. All the ISSR primers produced a total of 192 reproductive band profiles, none of which were polymorphic. Furthermore, the micropropagated plants were successfully rooted and acclimatized to greenhouse conditions. In this study, we present a graph kernel multiple propagation index which considers all the possible parameters needing to be analyzed. Such an index is used for the first time for the determination of the optimum proliferation medium

    The effect of carnosine on lung injury induced by abdominal aortic ischemia-reperfusion

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    AMAÇ: Aortanın geçici olarak klemplenmesini gerektiren cerrahi girişimlerden sonra, alt ekstremitelerde iskemi/reperfüzyon (IR) hasarı ve akcigerlerde uzak organ hasarı oluşabilir. IR hasarında nötrofillerin aktivasyonunun önemli bir rol oynadığı bilinmektedir. Amacımız rat modelinde abdominal aortanın klemplenmesini takiben olusan akciğer iskemi reperfüzyon hasarında karnozinin etkisini araştırmaktır. GEREÇ ve YÖNTEM: Yirmidört adet Sprague-Dawley cinsi rat, rasgele ve esit sayıda (n=8) olmak üzere üç gruba ayrıldı. Grup 1 deki ratlarda batın açıldı ve abdominal aortları eksplore edildikten sonra hiçbir girişim yapılmadan tekrar kapatıldı. Grup 2'de abdominal aortaya klemp konuldu. 30 dakika iskemi süresinin sonunda klemp kaldırıldı ve 60 dakika reperfüzyon gerçekleştirildi. 2. grupdaki islemin aynısı karnozin verilen 3. gruba da uygulandı ve karnozin intraperitoneal yolla klemp kaldırılmadan 10 dakika önce, 250 mg/kg olarak verildi. Tüm gruplardaki ratlar reperfüzyon süresinin tamamlanmasıyla sakrifiye edildi. Histolojik inceleme ve biyokimyasal analizler için akciğer doku örnekleri alındı. BULGULAR: Akciğer dokusunda Grup 2'ye ait malonil dialdehit, süperoksit dismutaz, myeloperoksidaz, okside glutatyon ve total glutatyon değerleri kontrol grubundaki değerlere göre anlamlı derecede yüksek bulundu. (p<0,05). Grup 3'e ait malonil dialdehit ve okside glutatyon degerleri, aortik iskemi reperfüzyon grubundaki degerlere göre anlamlı derecede düsük bulundu (p<0,05). Immünohistokimyasal degerlendirmede iNOS için immünreaktivitenin grup 1'de olmadıgı, grup 2'de siddetli düzeyde oldugu grup 3'de ise hafif düzeyde oldugu görüldü. SONUÇ: Karnozinin, abdominal aortanın geçici iskemi reperfüzyon hasarına baglı olarak akcigerlerde olusan patolojik degisikleri önlemede yararlı etkileri bulunmaktadır.OBJECTIVE: The purpose of this study is to examine the effect of carnosine on ischemia reperfusion injury in lungs occuring after occlusion reperfusion of infrarenal abdominal aorta in rats. MATERIALS and METHODS: Twentyfour Sprague-Dawley rats were randomly divided into 3 groups (n=8). Sham laparotomy (control) group (Group 1) underwent laparotomy and dissection of the infrarenal abdominal aorta without occlusion. In aortic ischemia reperfusion groups (group 2 and 3), after laparotomy and exteriorization of the infrarenal abdominal aorta, aorta was occluded for 30 min ischemia and then the clamp was removed for 60 min reperfusion. In group 3; 250mg/kg carnosine, were given intraperitoneally 10 min before declamping aorta. The lung tissue specimens were taken for biochemical analysis and immunohistochemical examination. RESULTS: In lung specimens, malonil dialdehyde, oxidized glutathione and total glutathione levels, and superoxide dismutase and myeloperoxidase activities were significantly higher in the aortic ischemia reperfusion (group 2) than the sham laparotomy (control) group (p<0.05). Levels of malonil dialdehyde and oxidized glutathione were significantly lower in the aortic ischemia reperfusion and carnosine group (group 3) than the aortic ischemia reperfusion one (p<0.05). While iNOS immunoreactivities were severe in group 2 and mild in group 3, they were not observed in group 1. CONCLUSION: Carnosine was beneficial in prevention of lung injury after abdominal aortic occlusionreperfusion injury

    The positioning performance of low-cost GNSS receivers in the Precise Point Positioning method

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    Satellite-based positioning, which started being developed in the mid-1960s for military purposes, is now used in almost every area. For the studies single and/or double frequency receivers are used. The cost of a receiver and antenna couple that have capable of high coordinate accuracies ranges from 3000to3000 to 15000. With the production of Original Equipment Manufacturer (OEM) receivers, the cost of satellite-based location determination decreases to approximately one in 10 for the civilian user compared to the operations performed with geodetic receivers and antennas. However, although these receivers collect data in multi-Global Navigation Satellite System (GNSS) and frequencies, the accuracy of the coordinate values estimated is not as high as geodetic receivers and antennas. Therefore, it is necessary to carry out an accuracy study to obtain information about which studies can be used in. In this study, measurements were made at the UZEL point located on the roof of the Yıldız Technical University Geomatics Engineering Department by using the ZED-F9P-02B OEM multi GNSS receiver and ANN-MB L1/L2 multi-band GNSS patch antenna. The performance of the test results has been examined by comparing the results from CSRS(Canadian Spatial Reference System)-PPP with the coordinates of the UZEL point. As a result of the comparison, the difference between the coordinate determined with collected 3.5 hr data and the coordinates of the UZEL point has been determined as – 1.4 cm, 2.8 cm, and 9.3 cm in the East, North, and Height directions, respectivel

    Left Atrial Function Is Improved in Short-Term Follow-Up after Catheter Ablation of Outflow Tract Premature Ventricular Complexes

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    Background: Association of premature ventricular complexes (PVC) with left ventricular systolic dysfunction (LVSD) and efficacy of catheter ablation treatment have been demonstrated in studies. The role of left atrial (LA) mechanics in the etiopathogenesis of PVC-induced cardiomyopathy (PVC-CMP) as well as changes in LA mechanics with catheter ablation have not been studied before. Methods: A total number of 61 patients (Mean Age 43 ± 3) with idiopathic outflow tract (OT) PVCs undergoing radiofrequency catheter ablation (RFCA) were enrolled. ECG, 24 h Holter, and echocardiographic evaluation with left ventricular (LV) diastolic functions and LA volumetric assessments were performed before and three months after RFCA. Results: Along with a marginal increase in left ventricle ejection fraction (LVEF), improvement in diastolic functions and left atrial mechanics were observed in the study (LVEF 53 ± 7 versus 57 ± 6, p < 0.01) in short-term follow-up. The frequency of LV diastolic dysfunction (LVDD) decreased with catheter ablation (n = 5 to 0, p = 0.02). The overall LA function improved. Left atrium passive and overall emptying fraction (LAEF) increased significantly (0.32 ± 0.04 to 0.41 ± 0.04, p < 0.05 and 0.62 ± 0.04 to 0.65 ± 0.004, p < 0.05, respectively). Active LAEF decreased significantly (0.29 ± 0.005 to 0.24 ± 0.006, p < 0.05). Conclusions: The results of this study are indicative of "PVC-induced atriomyopathy" which responds to RFCA in short-term follow-up. Atrial dysfunction might play a role in symptoms and etiopathogenesis of LVSD

    Closing Water Cycles in the Built Environment through Nature-Based Solutions: The Contribution of Vertical Greening Systems and Green Roofs

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    Water in the city is typically exploited in a linear process, in which most of it is polluted, treated, and discharged; during this process, valuable nutrients are lost in the treatment process instead of being cycled back and used in urban agriculture or green space. The purpose of this paper is to advance a new paradigm to close water cycles in cities via the implementation of naturebased solutions units (NBS_u), with a particular focus on building greening elements, such as green roofs (GRs) and vertical greening systems (VGS). The hypothesis is that such “circular systems” can provide substantial ecosystem services and minimize environmental degradation. Our method is twofold: we first examine these systems from a life-cycle point of view, assessing not only the inputs of conventional and alternative materials, but the ongoing input of water that is required for irrigation. Secondly, the evapotranspiration performance of VGS in Copenhagen, Berlin, Lisbon, Rome, Istanbul, and Tel Aviv, cities with different climatic, architectural, and sociocultural contexts have been simulated using a verticalized ET0 approach, assessing rainwater runoff and greywater as irrigation resources. The water cycling performance of VGS in the mentioned cities would be sufficient at recycling 44% (Lisbon) to 100% (Berlin, Istanbul) of all accruing rainwater roof–runoff, if water shortages in dry months are bridged by greywater. Then, 27–53% of the greywater accruing in a building could be managed on its greened surface. In conclusion, we address the gaps in the current knowledge and policies identified in the different stages of analyses, such as the lack of comprehensive life cycle assessment studies that quantify the complete “water footprint” of building greening systems.info:eu-repo/semantics/publishedVersio

    Evaluation of patients with fibrotic interstitial lung disease: Preliminary results from the Turk-UIP study

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    OBJECTIVE: Differential diagnosis of idiopathic pulmonary fibrosis (IPF) is important among fibrotic interstitial lung diseases (ILD). This study aimed to evaluate the rate of IPF in patients with fibrotic ILD and to determine the clinical-laboratory features of patients with and without IPF that would provide the differential diagnosis of IPF. MATERIAL AND METHODS: The study included the patients with the usual interstitial pneumonia (UIP) pattern or possible UIP pattern on thorax high-resolution computed tomography, and/or UIP pattern, probable UIP or possible UIP pattern at lung biopsy according to the 2011 ATS/ERSARS/ALAT guidelines. Demographics and clinical and radiological data of the patients were recorded. All data recorded by researchers was evaluated by radiology and the clinical decision board. RESULTS: A total of 336 patients (253 men, 83 women, age 65.8 +/- 9.0 years) were evaluated. Of the patients with sufficient data for diag-nosis (n=300), the diagnosis was IPF in 121 (40.3%), unclassified idiopathic interstitial pneumonia in 50 (16.7%), combined pulmonary fibrosis and emphysema (CPFE) in 40 (13.3%), and lung involvement of connective tissue disease (CTD) in 16 (5.3%). When 29 patients with definite IPF features were added to the patients with CPFE, the total number of IPF patients reached 150 (50%). Rate of male sex (p<0.001), smoking history (p<0.001), and the presence of clubbing (p=0.001) were significantly high in patients with IPE None of the women <50 years and none of the men <50 years of age without a smoking history were diagnosed with IPE Presence of at least 1 of the symptoms suggestive of CTD, erythrocyte sedimentation rate (ESR), and antinuclear antibody (FANA) positivity rates were significantly higher in the non-IPF group (p<0.001, p=0.029, p=0.009, respectively). CONCLUSION: The rate of IPF among patients with fibrotic ILD was 50%. In the differential diagnosis of IPF, sex, smoking habits, and the presence of clubbing are important. The presence of symptoms related to CTD, ESR elevation, and EANA positivity reduce the likelihood of IPF
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