Evaluation of performance of piled-raft foundations on soft clay: A case study

Khanmohammadi, Mohammadreza,Fakharian, Kazem Techno-Press 2018 Geomechanics & engineering Vol.14 No.1

Applicability of constructing piled raft foundations on soft clay has been given attention in recent years. Lack of sufficient stiffness for soil and thus excessive settlements to allow higher contribution of piles is the major concern in this regard. This paper presents a numerical investigation of performance of piled-raft foundations on soft clay with focusing on a case study. A 3D FEM numerical model is developed using ABAQUS. The model was calibrated by comparing physical and numerical modeling results of other researchers. Then the possibility of using piled-raft system in construction of foundation for a water storage tank in Sarbandar, Iran is assessed. Soil strength parameters in the numerical model were calibrated using the instrumentation data of a heavily instrumented preloading project at the construction site. The results indicate that choosing the proper combination of length and spacing for piles can lead to acceptable differential and total settlements while a high percentage of total bearing capacity of piles can be mobilized, which is an efficient solution for the project. Overall, the construction of piled-rafts on soft clays is promising as long as the total settlement of the structure is not imposing restrictions such as the common 25 mm allowable settlement. But instead, if higher allowable settlements are adopted, for example in the case of rigid steel tanks, the method shall be applicable with considerable cost savings.

Sequential optimization strategy for hyaluronic acid extraction from eggshell and its partial characterization

Mehdi Khanmohammadi,Ali Baradar Khoshfetrat,Shahla Eskandarnezhad,Najimeh Feyze Sani,Sirus Ebrahimi 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

The optimization of hyaluronic acid (HA) extraction from eggshell was studied by using a sequentialexperimentation approach. Using the results of factorial experiments, optimization experiments werecarried out by response surface methodology. The experimental data as well as the validation testsshowedthe optimum performance when the extraction pH and time were bounded in the ranges of 3.4–3.5 and3–3.4 days, respectively, at 9 ℃. The purified HAwas characterized by FTIR spectrum, harmonic mean sizeand average molecularweight. The study depicted the potential of eggshell as an alternative source for HAextraction to use in industry and medicine.

Spectrophotometric evaluation of the photocatalytic degradation of formaldehyde by Fe2O3–TiO2 nano hybrid

Mohammadreza Khanmohammadi,Amir Bagheri Garmarudi,Hamideh Elmizadeh,Mohammad Babaei Roochi 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Photocatalytic capabilities of sol–gel synthesized Fe2O3–TiO2 nano hybrid was investigated in degradation of formaldehyde in presence of ultra violet and visible irradiation. The reaction stream was evaluated by UV–vis spectrophotometry at 330–500 nm spectral region, using Fluoral-P (4-amino-3-penten-2-one) as a complexing agent. Obtained results confirmed the effective role of Fe2O3 phase in nano hybrid for degradation of formaldehyde according to Baeyer–Villiger reaction. On the other hand TiO2 would play the role of photocatalyst in presence of UV ray. Nano hybrid assisted process was monitored by spectrophotometry, utilizing multivariate curve resolution chemometric technique.

The Importance of Branding London as a Global Tourism Destination in UK.

Marzieh Khanmohammadi 세계문화관광학회 2011 Conference Proceedings Vol.12 No.-

As more tourism destinations emerge and competition for visitors becomes more intense a destination's ability to project itself on the world stage and differentiate itself from others is ever more important. London has undoubtedly the highest popularity among international tourists.It is also dominant in terms of the amount of heritage-related investment. So brandig London not only as a real cultural capital but also as one of the coolest global cities as the hospitable and safe multi-cultural host of the 2012 Olympics is very important for UK tourism development. This new brand image is so different from the traditionally held view of the city of Harrods the Royal Family. The study aims to discuss the following objectives: Reviewing the literature of branding destinations and related concepts; The advantages of branding London city as a means of promoting the city's features positive image and benefits by giving an example of successful destinations in branding management process. The importance of branding for 2012 Olympic Games The result of the study shows that the real competition between tourism destinations based on intangible to urism services such as providing tourists expectation security satisfaction and positive image which happens by branding the destination image as a safe and hospitable location. Therefore in order to enhance tourism in london as a UK dominant heritage site the tangible and intangible tourism services and attractions should be combined together.

Repair of Osteochondral Defects in Rabbit Knee Using Menstrual Blood Stem Cells Encapsulated in Fibrin Glue: A Good Stem Cell Candidate for the Treatment of Osteochondral Defects

Manijeh Khanmohammadi,Hannaneh Golshahi,Zahra Saffarian,Samaneh Montazeri,Somaye Khorasani,Somaieh Kazemnejad 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.3

BACKGROUND: In recent years, researchers discovered that menstrual blood-derived stem cells (MenSCs) have the potential to differentiate into a wide range of tissues including the chondrogenic lineage. In this study, we aimed to investigate the effect of MenSCs encapsulated in fibrin glue (FG) on healing of osteochondral defect in rabbit model. METHODS: We examined the effectiveness of MenSCs encapsulated in FG in comparison with FG alone in the repair of osteochondral defect (OCD) lesions of rabbit knees after 12 and 24 weeks. RESULTS: Macroscopical evaluation revealed that the effectiveness of MenSCs incorporation with FG is much higher than FG alone in repair of OCD defects. Indeed, histopathological evaluation of FG ? MenSCs group at 12 weeks posttransplantation demonstrated that defects were filled with hyaline cartilage-like tissue with proper integration, high content of glycosaminoglycan and the existence of collagen fibers especially collagen type II, as well as by passing time (24 weeks post-transplantation), the most regenerated tissue in FG ? MenSCs group was similar to hyaline cartilage with relatively good infill and integration. As the same with the result of 12 weeks post-implantation, the total point of microscopical examination in FG ? MenSCs group was higher than other experimental groups, however, no significant difference was detected between groups at 24 weeks (p > 0.05). CONCLUSION: In summary, MenSCs as unique stem cell population, is suitable for in vivo repair of OCD defects and promising for the future clinical application.

The Importance of Branding London as a Global Tourism Destination in UK

Marzieh Khanmohammadi 한국문화관광학회 2011 문화관광연구 Vol.13 No.2

As more tourism destinations emerge and competition for visitors becomes more intense, a destination’s ability to project itself on the world stage and differentiate itself from others is ever more important. London has undoubtedly the highest popularity among international tourists. It is also dominant in terms of the amount of heritage-related investment. So, brandig London not only as a real cultural capital but also as one of the coolest global cities, as the hospitable and safe multi-cultural host of the 2012 Olympics is very important for UK tourism development. This new brand image is so different from the traditionally held view of the city of Harrods, the Royal Family. The study aims to discuss the following objectives: Reviewing the literature of branding destinations and related concepts; The advantages of branding London city as a means of promoting the city’s features, positive image and benefits by giving an example of successful destinations in branding management process; The importance of branding for 2012 Olympic Games. The result of the study shows that the real competition between tourism destinations based on intangible tourism services such as providing tourists expectation, security, satisfaction and positive image which happens by branding the destination image as a safe and hospitable location. Therefore, in order to enhance tourism in london as a UK dominant heritage site the tangible and intangible tourism services and attractions should be combined together.

THE IMPACT OF SAFETY AND SECURITY ON HOSPITALITY AND CUITURAL TOURISM DEVELOPMENT

Marzieh Khanmohammadi 세계문화관광학회 2009 Conference Proceedings Vol.10 No.0

Tourism is a very delicate and sensitive industry especially in relation with safety and security matters in different national, regional and international levels. Every kind of security incidents such as:crime against tourists, war, riots and terrorism will cause irrecoverable damage to the industry. Today's tourists want to be assured of security, value, hospitality and comfort in these stormy times. Safety and security plays a major role in the new paradigm and in people's decision-making about where to travel. It goes together with sustainability based on responsible hospitality which emphasis on value rather than volume. Therefore, establishing hospitality with safety and security focal points at comfort and satisfaction of tourists is urgnt for sustainable tourism development in destinations and safety and security are vital to providing quality in tourism and it is known as the universal power which protect tourism. Therefore, Security should be evaluated as an impressive factor on tourism industry and it is considered as the main axies of all the plans and has the main role in stability of cultural, natural and human-made resources as tourism attractions. The aim of this paper is focusing on tourism security related matters on developing plans to deal with natural and human- made disasters,(such as crime against tourists, terrorism, wars and so on...), health and the physical, psychological and integrity of travellers, food safety, standardizing and quality of tourism goods and services and hospitality which increase guest satisfaction and make them travel further and improve market keeping action. Finally, the destination management and continuous improvement of quality in the fields of safety and security on tourism services is a tool for competition, excellence and tourism development. So, promotion of tourism services quality and prevention of incidents and crises management (prevention/reduction) are functional strategies in order to improve cultural tourism.

The Importance of Branding on Tourism Destination Image

Marzieh Khanmohammadi 세계문화관광학회 2010 Conference Proceedings Vol.11 No.0

The tourism industry generates many jobs which in they turn generate revenue for the destinations. But in order to take part of this revenue, destinations must first attract the tourists. This is done with destination branding and destination imaging which means that the image and the brand of a destination are playing a significant role. As more tourism destinations emerge and competition for visitors becomes more intense, a destination‘s ability to project itself on the world stage and differentiate itself from others is ever more important. As tourism destinations become more substitutable due to increasing competition in global tourism markets, destination personality and positive image which is seen as an important factor for building destination brands and crafting a unique identity for tourism places. The study aims to discuss the following objectives: ? Reviewing the literature of branding destinations and related concepts; ? The advantages of branding the city as a destination as a means of promoting the city‘s features and benefits by giving an example of successful destinations in branding management process. ? The elements of brand identity and branding destination management. ? The role of destination image on tourism industry and tourists behaviour; ? The importance of creating branding in distorted destination like Iran for removing and changing the negative image of visitors; The result of the study shows that the real competition between tourism destinations based on intangible tourism services such as providing tourists expectation, security ,satisfaction and positive image which happens by branding the destination image as a safe and hospitable location. Besides, branding is at the very heart of marketing strategy, and so the purpose of all destination marketing activity must be to enhance the value of the brand. Therefore, brandig with long time marketing process is essential for enhancing destination image among visitors and assists DMOs in measuring achievements. So branding strategies finalized to growth the competitive of the tourist destinations image.

Novel plastic hinge modification factors for damaged RC shear walls with bending performance

Komarizadehasl, Seyedmilad,Khanmohammadi, Mohammad Techno-Press 2021 Advances in concrete construction Vol.12 No.4

This paper introduces several new damage states for shear walls with flexural behavior damaged in an earthquake. These damage states are deducted by carefully interpretation of reported available test results of shear walls in the literature. Moreover, two methods for obtaining the plastic hinge modification factors of strength, stiffness and ductility capacity of the damaged shear walls with the flexural behavior are presented. A method based on secant stiffness at maximum displacement of each cycle of observed damage and the second method uses the reloading stiffness of the hysteresis curves consistent with damage levels. The later method introduced in this research is more reasonable for obtaining modification factors among the introduced methods. Using these factors, a reliable residual capacity for damaged structures can be assessed and the proper seismic retrofitting method can be followed. In this research, the effects of damages caused by various experimental tests have been studied on 43 reinforced concrete shear walls with flexural behavior. By introducing and describing the bending performance's damage levels, given the shear wall's observable condition such as cracks' width, concrete spalling and crushing, conditions of longitudinal and transvers rebars, 10 damage levels are introduced. The factors of modification of stiffness, strength, and the acceptable range of ductility of the member (𝜆k, 𝜆Q, and 𝜆D) were proposed for each level of damage. The results show that almost across all damage levels, the damage grew with increased drift. Nonetheless, stiffness and ductility modification factors are constant during the first damage states; they decrease dramatically after the third damage state (DS4). However, the reduction of the strength decreased gradually as of the fourth damage state. the results presented in current research are more reliable estimation of reduction factors in comparison with current approaches.

A Soft Robotics Nonlinear Hybrid Position/Force Control for Tendon Driven Catheters

Minou Kouh Soltani,Sohrab Khanmohammadi,Farzan Ghalichi,Farrokh Janabi-Sharifi 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.1

Minimally invasive steerable catheters, commonly implemented in cardiac ablation, are currently operatedby interventionalists exposing them to X-ray radiation and requiring the dexterity for accurate steering. Toconduct robot-assisted cardiac ablation, highly accurate stable control platform for precise force/position controlon the moving tissue is required. This paper introduces hybrid force/position control strategy to apply a constantforce to the cardiac tissue while tracking the desired trajectory. The position controller is based on a nonlinearmodel predictive tracking control satisfying the input constraints. Cosserat rod theory is incorporated for the distalshaft modeling of tendon-driven catheters, and the model is reformulated for controller design and stabilityproof. Lyapunov-based stability analysis is conducted. To apply the controller, the force-displacement mapping ofthe cardiac tissue is obtained through ex vivo experimental tests. The performance of the controller is evaluated,and the catheter is capable of regulating the force with the RMSE of 4.9 mN and tracking the position with theRMSE of 0.89 mm. The promising results verify the potential of the application of the introduced approach in realapplications including in vitro and clinical cardiac ablation.