191 research outputs found
Vibrations due to Dynamic Compaction
Ground vibrations due to dynamic compaction (DC), at a harbor site were measured to investigate whether the magnitude of vibrations were unacceptably strong to cause any damage to or increase existing damage on the surrounding structures experienced August 17, 1999 Kocaeli, Gölcük earthquake (M~7.4). The site is located in city of Kocaeli at the seaside of The Port of Derince. It was a reclaimed land formed with Hereke limestones. The measured data included vibrations induced by the tamping energy of DC both at the vicinity of nearby structures and within the DC site. The site was surrounded by a shallow isolation trench all along the land sides. This paper presents the case and the characteristics of vibration such as peak values of the records, Fourier spectrum and amplitude attenuations over distance. The predominant frequencies and amplitude of vibrations were compared to the related code limits to estimate the effect of vibrations on the existing structures
Preventing of Cathode Passivation/Deposition in Electrochemical Treatment Methods – A Case Study on Winery Wastewater with Electrocoagulation
A Review of State-of-the-Art Technologies in Dye-Containing Wastewater Treatment – The Textile Industry Case
Recently, new single or hybrid/combined processes have attracted much attention for treatment of textile and dyeing wastewaters. These processes which may be termed as “state of the art technologies” are membrane separation processes, ultrasonic, photochemical and electrochemical processes. Although the conventional methods still have been tried with some new materials such as, new adsorbents or coagulants, employing the new generation methods such as, electrocagulation-electrooxidation, sonooxidation or photo oxidation are gaining in popularity when the treatment of textile wastewaters is discussed. The purpose of the book chapter is to bring an overview on the new treatment methods for textile wastewaters, one of the most important source of environmental pollution. Despite the fact that there is no uniform standard currently, many countries have legalized some strict discharging standards and scientists and researchers face new technologies including electrical, sonic, magnetic, optical and thermal methods. Although many researches on treatment of synthetic or real wastewaters with various methods are available, very few researches have been carried out on the cutting-edge technologies. Moreover, there are a lot of review article or book chapters on textile wastewater treatment processes individually based on each conventional process such as coagulation, adsorption, chemical oxidation, and biological decolorization. Therefore, in this part of the book, following major and minor titles are stated truly on the aforementioned new technologies. Besides, these parts are not only about cutting-edge technologies, but also related with conventional methods and their new applications in colored wastewater treatment area briefly
Textile Materials in Liquid Filtration Practices: Current Status and Perspectives in Water and Wastewater Treatment
Filtration is considered the keystone of water and wastewater treatment and is used for various purposes, such as sludge dewatering and concentrating any solution. Moreover, as an advanced filtration technology, membranes can remove materials ranging from large visible particles to molecular and ionic chemical species. Proper selection of filter media/membrane material in filtration processes is often the most important consideration for assuring efficient separation. Filter media can be classified by their materials of construction, such as cotton, wool, linen, glass fiber, porous carbon, metals, and rayons. Recently, new polymeric materials have been used both individually and/or blended in filtration processes for the treatment of waters and wastewaters. The purpose of this chapter is to bring an overview on the textile-originated filter materials in filtration applications from conventional filtration to advanced membrane processes. Although many researches on filter media are available, very few researches have been carried out on the cutting-edge technologies about using filter materials on filtration processes from classical to advanced membrane processes. Therefore, in this part of the book, following major and minor titles are stated truly on the aforementioned new technologies and linked with conventional methods in water and wastewater treatment applications
Examination of Changes in Certain Biochemical Parameters Before and After Acute Training in Kick Boxers
Kickbox is one of the modern martial sports. The psychophysiological demands of a kickbox competition require that athletes achieve high thresholds in various aspects of physical fitness.The aim of this study is to analyze and evaluate the physiological properties of kickbox athletes and the activity profile properly in order to put forward proposals for training and new scientific research fields. The blood samples, which were taken before and after the maximal training applied to athletes according to the period, were studied. A total of 50 athletes, including 39 male and 11 female amateurs, were included in the study, with an average age of 20.08±6.33 years. All participants were informed about the study and necessary approvals. There was a significant difference between males and females in terms of BMI (Body Mass Index). It was observed that the GSH values of the athletes increased before and after training in both males and females. On the other hand, IL-1B (interleukin) only increased in males (p<0.05). The information obtained shows that the analyses of the before and after training male kickboxers at the amateur level are significantly more different than that of women. Since GSH is an effective tripeptide of antioxidants involved in the detoxification of harmful compounds, its synthesis is very important for metabolism. It can be said that GSH (glutathione) level may increase with normal exercise in daily life and training in athletes. Furthermore, the athletes should be analyzed metabolically well in response to the stress that may be caused by heavy exercise, and the exercise for improving performance should be achieved by detecting biochemical changes
Energy dissipation characteristics of slab type buildings with special connectors
The latest developments in the construction technologies and the materials facilitated the practicing engineers to go higher and energy-efficient buildings. However, the safety of the buildings and the residents has been an issue all the time. This is not an exception for the precast structures. The advantages of the precast elements are the quality assurance and the rapid erection on the site and challenged by the connection details and their performances during the extreme loading cases such as earthquakes. The utilization of a special mechanical connection of the precast members have been in the focus of the recent works in Istanbul Technical University (ITU-STEELAB). The prototypes of the proposed special connectors, called as cushion, were tested in STEELAB in order to determine the mechanical properties such as lateral and axial stiffness and the failure modes. Once the properties were determined, a hypothetical building of single story multi-bay slab type structure was modeled in the computer framework capable of substituting various parametric values into the model, processing and extracting the results for statistical analysis, SAMA. SAMA is developed based on the use of SAP 2000 OAPI functions called in MATLAB and Python scripts. In the hypothetical model, the cushions were modeled as link elements and placed between all the precast elements including foundation-cladding interface. Extensive non-linear time-history analysis was conducted to identify the damage localization by comparing the energy dissipation at each mechanical connector under ground motion records selected according to focal distance, site conditions and intensity. The preliminary results reveal that the cushions are effectively dissipating a significant amount of energy and mitigating the collapse of the precast elements. The more detailed conclusions will be discussed in the near future.Publisher's Versio
Usage of a special shotcrete panel to strengthen reinforced concrete frames
Duvarların püskürtme beton ile güçlendirilmesi yöntemi, ülkemizde hasarlı veya hasarsız yığma binaların güçlendirilmesi amacıyla yaygın olarak kullanılmaktadır. Bu yazıda, püskürtme beton kullanarak; ülkemizdeki betonarme yapılara yönelik uygun, etkili, kolay uygulanabilir ve ekonomik bir güçlendirme yöntemi önermek amacı ile yapılmış olan çalışmanın bir kısmı sunulacaktır. Püskürtme beton ile güçlendirme yönteminin betonarme çerçevenin yatay yük taşıma, enerji yutma kapasitesi ve rijitlik özelliklerine olan etkisi ile sistemin göçme şekli incelenmiştir. Ülkemizdeki betonarme yapıların genel özelliklerini yansıtan tek katlı ve tek açıklıklı ½ ölçekli düzlem çerçevelerin içerisine tuğla duvar yerine ıslak karışımlı püskürtme beton paneller eklenmiştir. Oluşturulan panel; dış çerçevenin kirişlerine kayma kamaları kullanılarak bağlanmış, duvar ve çerçevenin birlikte çalışması amaçlanmıştır. Panel, kolon iç yüzeyine 20 cm mesafeli olarak yerleştirilmiştir. Panel genişliğine karar verirken, çerçeve kirişinde yatay ve düşey yükler etkisinde göreli olarak daha az eğilme momenti meydana gelen bir bölgede kalınması hedeflenmiştir. Üretilen numuneler, sabit düşey yük ve tersinir tekrarlı yatay yük çevrimleri etkisinde denenmiştir. Yalın çerçeve ile püskürtme beton bölme duvarlı çerçeve davranışları karşılaştırıldığında, önerilen güçlendirme yöntemi ile sistemin yatay yük taşıma kapasitesinin yaklaşık 1.6 kat arttığı gözlenmiştir. Püskürtme beton ile oluşturulan duvarın sistem davranışına etkisi analitik olarak da incelenmiştir. Anahtar Kelimeler: Püskürtme beton, güçlendirme, betonarme çerçeve.The existence of many vulnerable reinforced concrete buildings in earthquake prone areas that were built before the current Turkish earthquake code, presents one of the most serious problems facing Turkey, especially in Istanbul today. During 1999 Kocaeli Earthquake, buildings had greater damage than expected at that magnitude of an earthquake in the city. Since then researchers have been trying to find cheap and easily applicable strengthening solutions for the reinforced concrete and masonry structures. Shotcrete is used in lieu of conventional concrete, in most instances, for reasons of cost or convenience. Properly applied shotcrete is a structurally sound and durable construction material which exhibits excellent bonding characteristics to existing concrete, rock, steel, and many other materials. It can have high strength, low absorption, good resistance to weathering and resistance to some forms of chemical attack. Shotcrete is used for repairing of bridges, buildings, marine structures; underground excavations in rock; slope and surface protection and for new structures such as building pools, tanks, walls, floors and domes. Shotcrete can be applied by two distinct application techniques; the dry-mix process and the wet-mix process. In this study wet-mix shotcrete is used. Retrofitting structures with shotcrete is commonly used for damaged and undamaged masonry structures in Turkey. The aim of this study is to adapt this retrofitting technique to find out whether it is fast, cheap and adequate method for reinforced concrete structures. To understand the effect of this retrofitting technique, experimental research has been carried out. Panels made from wet-mixed shotcrete in lieu of a traditional masonry are used to form an infill wall within a vulnerable reinforced concrete frame. The frames were chosen to represent weak column/strong beam type structures that were very common in Turkey especially for the buildings constructed before the current earthquake code. The experimental work is composed of strengthening of one undamaged and one bare frame. Nearly ½ scale one story, one bay specimens were tested under constant vertical loads acting on the columns and lateral reversed cycling loads. The panel is connected to the beam and the foundation through shear studs used at two edges of the infill wall to create strong bond between panel and reinforced concrete members of the frames. They are connected by lapping the infill reinforcement to the anchorage placed in frame members. The panel has 20 cm distance to the columns. The specimens had non-seismic details such as large spacing of hoops, no hoop in beam-column connection region and no use of 135° seismic hooks. One story, one bay reinforced concrete frames with a portion of slab on top and a foundation at the bottom have been constructed in the laboratory. The cross sectional dimensions of columns and beam of the frames are 20 cm by 25 cm and 20 cm by 32.5 cm, respectively. The height and the width of the frames are 152.5 cm and 220 cm, respectively. Main reinforcement of the frames was consisted of 16 mm steel bars (average yield stress, fy = 270 N/mm2) and the reinforcement of the panels 4.5 mm steel bars (average yield stress, fy = 320 N/mm2). The reinforcement ratio of the column and the panel are 1.6% and 0.2% respectively. A wire mesh (Q 106/106) consisting of 4.5 mm steel bars was placed in the middle of the frame. By lapping the infill reinforcement to the anchorages placed in the frame members, full contact of the panel was established. The anchorages used were 10 mm steel bars placed in the frame by epoxy resin. The length of the anchorage in the panel was 20 cm. By using wet-mixed sprayed concrete, a 5 cm-thick panel was formed. The axial load applied on each column is 132.5 kN. Lateral reversed cycling loading imposed as displacement was applied to the specimen by means of a 250 kN-capacity hydraulic MTS actuators, which were placed at the slab level. Up to 0.467 mm top displacement, the cycles were applied only once. Later target displacements were repeated three times up to 42 mm. In this study, the effect of the technique on load carrying capacity, energy dissipation, rigidity and the failure mode of the frame is investigated with experiments. The results of the experiments show that the lateral load carrying capacity of the infilled frames strengthened using this method are approximately one and a half times that of the bare one. Keywords: Shotcrete, strengthening, reinforced concrete frame
Effect of visitor activities on topsoil hydrophysical properties in two protected areas in northern blacksea region
In this study, the effects of visitor acitivities on topsoil hydrophysical properties in two protected areas in northern Bleacksea region were investigated. For this purpose, soil samples taken from study area that was characterized as heavily trafficked site (HTS), moderately trafficked sites (MTS) and control (non-trafficked site). The soil bulk density and soil penetration resistance increased from 1.02 to 1.39 g cm–3 and 0.66 to 1.55 MPa, respectively, saturated hydraulic conductivity decreased from 60.60 to 10.35 mm h–1 in moderately and heavily trafficked sites, respectively, at 0–10 cm soil depth in Ayder protected area. The soil bulk density and soil penetration resistance increased from 0.85 to 1.40 g cm–3 and 0.68 to 1.50 MPa, respectively, saturated hydraulic conductivity decreased from 58.75 to 10.35 mm h–1 in moderately and heavily trafficked sites, respectively, at 0–10 cm soil depth in Kafkasor protected area. The intensity of visitor activities had a negative impact on topsoil hydrophysical properties in the study area in Ayder and Kafkasor. The principles of management in Ayder and Kafkasor protected areas should be revised, and use of this area without a plan should be stopped as soon as possible
Cervical Priming Before Diagnostic Operative Hysteroscopy in Infertile Women: A Randomized, Double-Blind, Controlled Comparison of 2 Vaginal Misoprostol Doses
The aim of this study was to evaluate the efficacy of vaginal misoprostol for cervical priming at doses of 200 mcg and 400 mcg, 12 to 15 hours before diagnostic office hysteroscopy (OH) without anesthesia in patients with infertility. Sixty infertile patients requiring a diagnostic office hysteroscopy for investigation of infertility were included in the study. The patients were randomly allocated into 3 vaginally administered misoprostol groups: (1) control group, (2) 200-mcg dose group, and (3) 400-mcg dose group. Misoprostol significantly facilitated the procedure of OH: cervical entry was easier; procedural time was shorter; baseline cervical width was larger; and pain scoring was lower in the misoprostol groups compared with the control group. Increasing the dose of misoprostol from 200 mcg to 400 mcg did not improve the effect on cervical dilation. Misoprostol is a promising analog to use for cervical priming before OH. Since doses of 200 mcg and 400 mcg vaginal misoprostol 12 hours before the OH both have proven to be effective regimens, 200 mcg may be preferred. However, before routine clinical usage, further research is needed through large, randomized, controlled trials powered to detect a difference in complications to determine whether misoprostol reduces complications in OH.Scientific Research Projects Coordination Unit of Istanbul UniversityIstanbul University [26324]An earlier version of this research was presented at the 42nd Annual Meeting of American Society of Reproductive Medicine in San Diego, 2012. This was made possible by funding from the Scientific Research Projects Coordination Unit of Istanbul University (grant 26324)
- …