1,721,257 research outputs found
OPTIMIZING THE PERFORMANCE OF THE INDUSTRIAL ROBOT CTFLEX IN PACKAGING AUTOMATION SYSTEMS
No full textThis experimental Ph.D. research, developed within the CT Pack company, manufacturer of machines and plants for food packaging, aims at improving the performance (i.e. in terms of products per minute) of the operations of picking and placing of products in a packaging line. In particular, the objective is to develop a new Delta robot, fully realized inside the company, with unique mechanical features in terms of payload capacity with using the latest technologies for industrial automation and control.
This research illustrates the development of a novel parallel Delta robot. The kinematic structure known as Delta robot is one of the most important inventions in the industrial machinery sector, mainly used in the packaging industry. The robot specifically developed in CT Pack Company is called CTFLEX. Its development consists of choosing the proper control hardware and creating the programming software to configure new characteristics as mechanically performed; the software has been chosen to be the same used in PLC controllers of the machines, obtaining a robot well integrated into the same line. This research will further demonstrate the uses of this robot, the steps during software development and the optimization of its performanceThis experimental Ph.D. research, developed within the CT Pack company, manufacturer of machines and plants for food packaging, aims at improving the performance (i.e. in terms of products per minute) of the operations of picking and placing of products in a packaging line. In particular, the objective is to develop a new Delta robot, fully realized inside the company, with unique mechanical features in terms of payload capacity with using the latest technologies for industrial automation and control.
This research illustrates the development of a novel parallel Delta robot. The kinematic structure known as Delta robot is one of the most important inventions in the industrial machinery sector, mainly used in the packaging industry. The robot specifically developed in CT Pack Company is called CTFLEX. Its development consists of choosing the proper control hardware and creating the programming software to configure new characteristics as mechanically performed; the software has been chosen to be the same used in PLC controllers of the machines, obtaining a robot well integrated into the same line. This research will further demonstrate the uses of this robot, the steps during software development and the optimization of its performanc
Frequency control scheme for islanded distribution network with high PV penetration / Mohammad Hussein Mohammad Dreidy
Get PDFAir pollution due to fossil fuel power plants are causing serious environmental problems, which affect all aspects of life. Due to this, many governments and power utility companies are expressing great interest in Renewable Energy Sources (RESs). Generally, using RESs in a distribution system such as solar Photovoltaic (PV) decreases dependence on fossil fuel. However, at high PV penetration levels, an islanded distribution network suffers from critical frequency stability issues. This occurs due to two main reasons: first, the reduction of the distribution network inertia with high PV penetration, where in this condition, the rate of change of frequency (ROCOF) will be high enough to activate the load shedding controller, even for small power disturbance, and second, this type of networks has a small spinning reserve, where the PV generations are normally providing the maximum output power.
The main aim of this research is to develop a comprehensive frequency control scheme for islanding distribution networks with high PV penetration. This scheme is used to stabilize the frequency of the network to a value that is suitable for the islanded and reconnection processes. To achieve this aim, three different controllers were proposed in this scheme; inertia, frequency regulation, and under-frequency load shedding (UFLS) controllers. The inertia controller is designed for PV generation to reduce the network frequency deviation, which is initiated immediately during disturbance event. After a few seconds, a frequency regulation controller, which consists of primary and secondary frequency controllers, is activated. This frequency regulation controller was proposed to provide sufficient power from the Battery Storage System (BSS) to stabilize the frequency within a few minutes. When inertia and frequency regulation controllers fail to stop the frequency deviation, an optimal (UFLS) controller is initiated from Centralized Control System (CCS) to shed the required loads. On top of shedding loads, the CCS is used to manage the operation of frequency control scheme and reconnect the grid.
The proposed frequency control scheme and centralized control system were tested using a part of Malaysia’s distribution network (29-bus). The distribution network was modeled and simulated for different PV penetration levels using PSCAD//EMTDC software. The simulation results confirmed that the proposed scheme is able to stabilize the frequency of an islanded distribution network, with 50% PV penetration. This scheme is also capable of recovering the network frequency for small load and radiation changes just before it reaches the load shedding limit (49.5 Hz). Furthermore, at high PV penetration and large disturbance events, the proposed scheme can still recover the frequency by shedding the required loads within (0.254 seconds) without overshooting the frequency. Moreover, when the proposed frequency control scheme is coordinated with CCS, the islanded distribution network will be smoothly reconnected to the main grid. Therefore, this frequency control scheme has potential to be applied in real distribution networks with high PV penetration
The islamic realism of Sheikh Yusuf Qaradawi (1926–) and Sayyid Mohammad Hussein Fadlallah (1935–2010)
No full textThe article sheds light on the core realist assumptions—regarding international anarchy, the centrality of power to international relations and human nature—that underpin the international relations perspectives of two leading contemporary Islamist thinkers, Sheikh Yusuf Qaradawi (1926–) and the late Sayyid Mohammad Hussein Fadlallah (1935–2010). It further asserts that the law of mutual restraining—which Qaradawi and Fadlallah derive from the Qur’an—bears a major affinity to realism’s balance of power principle. It argues that Qaradawi and Fadlallah articulate a non-western variant of realism that this article refers to as Islamic realism. After defining Islamic realism, the article compares it to four strands of realism: structural, neoclassical, classical and Christian realism. The conclusion suggests that realism should not be viewed as exclusively a product of European experiences and western ‘secular’ thought, but as a mode of theorizing about international relations that transcends cultural boundaries. In addition, it underscores the links between religion and realism, calling for research into the likely sources of realism in the three Abrahamic religions.PublishedN/
In vitro propagation of Carica papaya L. cv. eksotika via somatic embryogenesis / Baker Mohammad Hussein al-Shara
Get PDFThis thesis summarizes the optimal protocols to achieve in vitro micropropagation of Carica papaya ‘Eksotika’ using somatic embryogenesis. Half strength MS medium supplemented with 10 mg L-1 Dichlorophenoxyacetic acid (2,4-D) and 18 mg L-1 of boric acid produced high yields of somatic embryos. ½ MS medium augmented with 10 mg L- 1 phloroglucinol was found to be best suited for embryo maturation. The well-formed embryos produced shoots in MS medium supplemented with 0.05% activated charcoal, elongated in MS medium supplemented with 1 mg L-1 gibberellic acid (GA3), 0.5 mg L-1 indol-3- acetic acid (IBA), 100 mg L-1 Myo-insitol and 3.76 mg L-1 riboflavin and produced roots in MS medium after being cultured for four days in full strength MS medium supplemented with 2 mg L-1 IBA. After the rooting phase, in vitro plantlets were acclimatized in peatmos soil. For artificial seeds, the somatic embryos encapsulated in MS medium without calcium demonstrated the highest percentage of shoot formation and the lowest percentage of callus formation at the base end of somatic embryos. Histological analysis demonstrated that somatic embryogenesis could be induced from embryogenic cells that originated in meristematic centers or from clusters of cells. The pro-embryos, globular-shaped embryos, heart-shaped embryos, torpedo-shaped embryos and cotyledonary stages were found to closely resemble the ontogeny of zygotic embryos. Active gene expression of all selected genes, namely CpLAX2, CpLAX3 and CpPIN4, were detected in all somatic embryos collected during the maturation and germination phases. All genes (CpLAX2, CpLAX3 and CpPIN4) were involved in the development and growth of somatic embryos
Design and Characterization of Flexible and Implantable Electrodes
No full textA Master of Science thesis in Biomedical Engineering by Aseel Dirar Alatoom entitled, “Design and Characterization of Flexible and Implantable Electrodes”, submitted in April 2019. Thesis advisor is Dr. Amani Al-Othman and thesis co-advisors are Dr. Hasan Awad Moh'd Al-Nashash and Dr. Mohammad Hussein Al-Sayah. Soft and hard copy available.Implantable bioelectrodes have the potential to advance neural sensing and muscle stimulation, especially in cases of peripheral nerve injuries. In such cases, the application of electrical stimulation to the muscles prevents muscular atrophy and helps to bridge the gap between the injured nerve and the corresponding muscle. Conventional materials for these implantable electrodes are usually metals, but they suffer from several limitations ranging from mechanical mismatch to immunological responses. Another problem is damage to tissues due to mechanical forces exerted on soft tissues by the stiff mechanical electrodes. Therefore, there is a need for the development of flexible, durable implantable electrodes with low interfacial impedance characteristics. This thesis discusses the fabrication and characterization of novel, low-cost, flexible bioelectrodes based on silicone polymer (polysiloxane) and other electrode materials, including titanium dioxide and stainless steel powder as well as their combinations. For this purpose, this work synthesized and characterized three types of implantable electrodes based on their electrochemical and mechanical properties; where titanium dioxide, stainless steel, and a mixture of the two were used as the main conducting components for fabrication. The titanium dioxide-based samples exhibited a bulk impedance of 353±13.5 Ω with an impedance of 198±183 kΩ at frequency of 1 kHz; in addition, they had a modulus of elasticity of 4.52±1.15 MPa. The stainless steel-based electrodes had a bulk impedance of 1.69±1.16 kΩ and an impedance of 1.21±1.13 MΩ at frequency of 1 kHz, and they had a modulus of elasticity of 0.722±0.393 MPa. The third type, which was a mixture of both titanium dioxide and stainless steel-based samples, had a bulk impedance of 1.71±0.849 kΩ and an impedance of 191 ± 160 kΩ at frequency of 1 kHz; along with a modulus of elasticity of 0.453±0.32 MPa. The results for the silicone with metal powders showed promising electrochemical and mechanical characteristics with flexible and ductile properties, with the titanium dioxide-based material performing the best. Compared with the values reported in the literature, the results show superior performance. Thus, supporting the composite material’s potential for being used in implantable electrode applications.College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Quand une fatwa défend le droit des femmes...
No full textPage d'accueil du site de Mohammad Hussein Fadlallah … bien peu de médias occidentaux s’y intéressent ! Et pourtant, à l’occasion de la "Journée mondiale de lutte contre les violences à l’encontre des femmes", une des plus grandes autorités religieuses chiites, cheikh Mohammad Hussein Fadlallah, a donné un "avis juridique" qui fait grand bruit dans l’ensemble du monde arabe.Le quotidien Al-Quds al-‘arabi raconte ainsi qu’en Jordanie, comme ailleurs dans la région, la journée de prière de vend..
Quand une fatwa défend le droit des femmes...
No full textPage d'accueil du site de Mohammad Hussein Fadlallah … bien peu de médias occidentaux s’y intéressent ! Et pourtant, à l’occasion de la "Journée mondiale de lutte contre les violences à l’encontre des femmes", une des plus grandes autorités religieuses chiites, cheikh Mohammad Hussein Fadlallah, a donné un "avis juridique" qui fait grand bruit dans l’ensemble du monde arabe.Le quotidien Al-Quds al-‘arabi raconte ainsi qu’en Jordanie, comme ailleurs dans la région, la journée de prière de vend..
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