18,590 research outputs found
TCP Congestion Control Identification
Transmission Control Protocol (TCP) carries most of the traffic on the
Internet these days. There are several implementations of TCP, and the most
important difference among them is their mechanism for controlling congestion.
One of the methods for determining type of a TCP is active probing. Active
probing considers a TCP implementation as a black box, sends different streams
of data to the appropriate host. According to the response received from the
host, it figures out the type of TCP version implemented.
TCP Behavior Inference Tool (TBIT) is an implemented tool that uses active
probing to check the running TCP on web servers. It can check several aspects
of the running TCP including initial value of congestion window, congestion
control algorithm, conformant congestion control, response to selective
acknowledgment, response to Explicit Congestion Notification (ECN) and time
wait duration. In this paper we focus on congestion control algorithm aspect of
it, explain the mechanism used by TBIT and present the results
Drillstring Vibration Analysis in Extended Reach Drilling (ERD) using WELLPLANTM
Oil and gas industry always aims efficient service with optimal expenses. This final
year project, aiming to deal with one of the most important parameters, that has
tremendous impact on drilling operations’ time and cost. This parameter as mentioned
above on the topic is a Drillstring Vibrations.
While drilling, Drillstring Vibration causes premature drillstring components and bit
failure [8], and is a waste of drilling energy. To increase drilling efficiency, drillstring
vibrations need to be monitored and analyzed and the optimum drilling parameters and
practices need to be achieved as a well is being drilled. This results in a reduction in the
drillstring failures and the amount of time spent tripping and/or fishing, and an increase
in both bit life and drilling rate.
Drillstring dynamics is one of the most important limiting factors in extended reach
drilling. This is because, long sections of the drillstring lie on the low side of the
wellbore while rotating. When the rotary speed exceeds a critical threshold the
drillstring starts to snake, sliding up and down the borehole wall [1]. If rotated further
beyond the threshold speed, the drillstring will eventually start to whir which can cause
severe damage to string components after only a short period of time [1]. Therefore, the
main scope of the project, considering the earlier mentioned issues, a WELLPLAN
software (Critical Speed Module) used. The project mainly dealt with drillstring, axial
stress, bending stresses and torsional oscillations known as stick-slip motion of the bit.
Besides the WELLPLANTM software, a matlab M.file was developed that uses some
predetermined equations to estimate the critical drillstring vibrations, and critical
operational speed taking into account the weight on bit, BHA length and rock
compressive strengt
Infraclavicular arterio-arterial prosthetic loop is a safe and effective vascular access technique for haemodialysis in frail patients: a prospective observational study
Vascular access failure causes significant morbidity among end stage renal failure patients. With the increased life expectancy and frailty of those patients, maintaining vascular access became a great challenge. In this study, we assess the short and midterm outcomes of infraclavicular arterio-arterial prosthetic loop (IAAPL) as vascular access for haemodialysis in frail patients who have exhausted conventional vascular access methods. A prospective observational study of 43 patients undergoing IAAPL was conducted in a single centre between May 2017 and March 2020. Primary, assisted primary and secondary patency rates were recorded in addition to complications and patient compliance with access. The achieved primary, assisted primary and secondary patency rates at 6 months are 87.5%, 95%, 97.5% respectively, at one year, corresponding rates were 75%, 83.3%, 94.4% and at 18 months they were 68.6%, 77.1%, 85.7% respectively. There was no procedure related mortality and life-threatening complications during the study period. So we can assume that infraclavicular AAPL is a safe and effective method of obtaining alternative vascular access for hemodialysis in frail patients for whom the conventional vascular access for hemodialysis is not suitable or contraindicated
Harnessing the plasmonic properties of gold nanoparticles: functionalization strategies coupled with novel spectroscopic tools
Metallic plasmonic substrates such as gold nanoparticles (AuNPs) have fascinated researchers due to their usefulness in verious interdisciplinary studies at the interface between applied physics, biochemistry, engineering, and medicine. A good understanding of the physics of these noble nanostructures, particularly the plasmonic and optical properties, can be employed to improve a
wide range of sensors and electronic devices. The relevance of molecular recognition and the binding of biological and chemical entities to diagnostics, biosensors, and drug delivery has attracted significant research interest. By addressing material functionalization design and advanced characterization methods, this doctoral work aims to highlight efforts to exploit the surface modification strategies to enhance the responsiveness of nanoparticle substrates for improved detection of health-relevant biomolecules. The self-assembly of small ligands, such as alkanethiols, and oligonucleotides on the surface of AuNPs provided a possible starting route for the preparation of bio-nanomaterials with precise physicochemical properties. The versatile AuNPs were optimized and thoroughly characterized by employing electron microscopy techniques such as transmission electron microscope (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM), spectroscopic techniques, including ultraviolet/visible (UV/Vis), dynamic light scattering (DLS), and thermal lens spectrometry (TLS), and biochemical assays (gel electrophoresis, Dot plot, Western plot, and the Enzyme Linked Immunosorbent Assay (ELISA)). Subsequently, the molecular recognition capabilities of functionalized AuNPs were investigated using multiple techniques, including novel detection routes such as the electrophoresis approach coupled with online TLS. This work establishes a versatile platform for AuNP engineering with controlled size and surface functionality. The strategies presented in this thesis aim to improve medical diagnostics to make them affordable for point-of-care scenarios to enhance the quality of human health.wide range of sensors and electronic devices. The relevance of molecular recognition and the binding of biological and chemical entities to diagnostics, biosensors, and drug delivery has attracted significant research interest. By addressing material functionalization design and advanced characterization methods, this doctoral work aims to highlight efforts to exploit the surface modification strategies to enhance the responsiveness of nanoparticle substrates for improved detection of health-relevant biomolecules. The self-assembly of small ligands, such as alkanethiols and oligonucleotides on the surface of AuNPs provided a possible starting route for the preparation of bio-nanomaterials with precise physicochemical properties. The versatile AuNPs were optimized and thoroughly characterized by employing electron microscopy techniques such as transmission electron microscope (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM), spectroscopic techniques, including ultraviolet/visible (UV/Vis), dynamic light scattering (DLS), and thermal lens spectrometry (TLS), and biochemical assays (gel electrophoresis, Dot plot, Western plot, and the Enzyme Linked Immunosorbent Assay (ELISA)). Subsequently, the molecular recognition capabilities of functionalized AuNPs were investigated using multiple techniques, including novel detection routes such as the electrophoresis approach coupled with online TLS. This work establishes a versatile platform for AuNP engineering with controlled size and surface functionality. The strategies presented in this thesis aim to improve medical diagnostics to make them affordable for point-of-care scenarios to enhance the quality of human health
Cross-Cultural Conflict and Pursuit of Identity in Ameen Rihani’s The Book of Khalid
Multiculturalism is an outcome of developing global culture emanating from ceaseless flow of people between nations and intercultural interactions. Crossing the borders results in psychological transformation of the immigrants as their ethnic identity shaped by social, religious, historical and political forces over decades is in continual flux. Though different kinds of responses to the situation of cultural multiplicity may be diagnosed, the fact remains that there are no simplistic ways of dealing with or responding to multiculturalism. The immigrants face cultural clash and find difficulties in acculturating. When the immigrants come to install in another country, they are accosted with a new culture, a new statute and a reserved group of people who do not mix so very easily. Everyone does not have the capacity to adjust their feelings and mind. They form a community of diaspora who are always reminded of their roots in an alien land. The impact of diasporic experiences on immigrants’ psyche depends on their level of belonging in an alien land. Ameen Rihani’s odyssey from Lebanon to United States gives him a cutting edge over his contemporaries to be established as most revered author of Arabs diaspora abroad. Rihani, molded and transformed by the cultures of his countries of origin, movement and settlement, has been earnestly engaged in re-conceptualizing the idea of diaspora as a profitable affair as opposed to the popular beliefs that render immigration and displacement as a condition of loss. His novels are bulging with different protagonists of staunch spirit and calibrating credence who win the tussle with cultural conflict and in the process evolve and finally lost. The aim of this paper is to demonstrate how Rihani’s protagonist Khalid in his novel of the same name evolves with cultural changes, endeavors for pursuit of identity in both origin and adopted worlds and finally takes control of his destiny
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