A narrative study of international postgraduate students’ conceptualization of academic writing through assessment feedback in a UK university

Academic writing is an essential skill for higher education and often used as a form of assessment. Academic writing is also very difficult to define due to its situated concept that varies from one academic context to another. This makes it especially difficult for international students who may have limited academic writing experience and whose first language is not English. Furthermore, previous studies often portray international students as students with deficits (Lee & Rice, 2007) due to the many documented cases reporting international students' difficulty when studying abroad, often presented as statistical or performance data and so giving a non-holistic picture. This narrative study looked at international students’ in-depth and holistic experience in conceptualizing academic writing, over 10 months period, taking into account the unique experiences of each participant. The study used blogs, and conversational semi-structured interviews as method for collecting data. These combinations were essential in order to ensure an ongoing longitudinal collection of data without being too intrusive towards the participants. The findings show that there were many interrelated factors involved in the journey of academic writing conceptualization which were both internal and external. Internal factors included the participants’ traits as a learner, their personality and motivation. External factors contributing in this study included the importance of external support that directly and indirectly determine how the participants perceive feedback, which in turn affects their writing behaviour. The importance of criticality as the focal essence of the UK academic writing was also discussed as it seemed to have an important cultural inference for some participants. Lastly, there was evidence of changes and development as well as the inability to change present and this is discussed in the study. This study concludes by providing a series of implications that could be considered not only by the UK universities and international students alike, but also for future student sponsors

Efficient Key Management Schemes for Smart Grid

With the increasing digitization of different components of Smart Grid by incorporating smart(er) devices, there is an ongoing effort to deploy them for various applications. However, if these devices are compromised, they can reveal sensitive information from such systems. Therefore, securing them against cyber-attacks may represent the first step towards the protection of the critical infrastructure. Nevertheless, realization of the desirable security features such as confidentiality, integrity and authentication relies entirely on cryptographic keys that can be either symmetric or asymmetric. A major need, along with this, is to deal with managing these keys for a large number of devices in Smart Grid. While such key management can be easily addressed by transferring the existing protocols to Smart Grid domain, this is not an easy task, as one needs to deal with the limitations of the current communication infrastructures and resource-constrained devices in Smart Grid. In general, effective mechanisms for Smart Grid security must guarantee the security of the applications by managing (1) key revocation; and (2) key exchange. Moreover, such management should be provided without compromising the general performance of the Smart Grid applications and thus needs to incur minimal overhead to Smart Grid systems. This dissertation aims to fill this gap by proposing specialized key management techniques for resource and communication constrained Smart Grid environments. Specifically, motivated by the need of reducing the revocation management overhead, we first present a distributed public key revocation management scheme for Advanced Metering Infrastructure (AMI) by utilizing distributed hash trees (DHTs). The basic idea is to enable sharing of the burden among smart meters to reduce the overall overhead. Second, we propose another revocation management scheme by utilizing cryptographic accumulators, which reduces the space requirements for revocation information significantly. Finally, we turn our attention to symmetric key exchange problem and propose a 0-Round Trip Time (RTT) message exchange scheme to minimize the message exchanges. This scheme enables a lightweight yet secure symmetric key-exchange between field devices and the control center in Smart Gird by utilizing a dynamic hash chain mechanism. The evaluation of the proposed approaches show that they significantly out-perform existing conventional approaches

Evaluasi Beban Torsi dan Drag pada Sumur Berarah Mila di Lapangan Lepas Pantai Laut Jawa Bagian Barat dengan Menggunakan Software Dswe

Pemboran berarah adalah sebuah teknologi pemboran dengan membelokkan lubang bor menuju kearah tertentu untuk mencapai target dibawah permukaan bumi yang telah ditentukan sebelumnya. Dalam pemboran berarah, timbulnya beban torsi dan drag yang ditanggung oleh rangkaian pipa bor merupakan salah satu faktor yang mempengaruhi keberhasilan pemboran. Tersebut Sumur Mila adalah salah satu sumur pengembangan gas yang terletak pada Cekungan Sunda yang berjarak kira-kira 50 mil arah Barat Laut dari Jakarta. Dalam kegiatan operasi pemboran pada sumur tersebut, dijumpai adanya peningkatan torsi yang tinggi dibeberapa titik pada saat kegiatan operasi pemboran sedang berlangsung. Salah satu penyebabnya adalah karena kondisi lubang bor yang tidak begitu baik, yaitu karena banyaknya cutting yang ditemukan pada lubang bor. Pada penelitian ini akan ditinjau faktor – faktor yang menyebabkan meningkatnya torsi dan drag pada proses pemboran sumur tersebut . Dan diharapkan dari hasil penelitian ini akan dapat diperoleh suatu cara penanggulangan yang tepat untuk mencegah terjadinya masalah yang mengakibatkan munculnya torsi dan drag yang tinggi

Early Proterozoic Birimian Gold Mineralization Of The Bogosu And Prestea Districts Of The Ashanti Gold Belt, Ghana, West Africa

Mesothermal gold ores of the Bogosu and Prestea concessions of southwestern Ghana are hosted by Birimian (2.1 Ga) carbonaceous sedimentary rocks. Gold mineralization is post-peak metamorphism, and occurs within dilatant zones of the Ashanti Structural Belt. Host sedimentary and mafic lithologies have been altered to an assemblage containing abundant ankerite, siderite and sericite.;Deeper portions of the gold system are exposed on the Prestea concession, and higher-level ores at Bogosu. Crack-seal quartz veins and carbonaceous shear-zones are the common ore types in the brittle-ductile rocks at Prestea. Tectonically-disrupted sediments with smaller zones of carbonate-altered mafic dikes are the common ore types at Bogosu.;Pyrrhotite was the first sulphide to precipitate; however, increase in pH and fO{dollar}\sb2{dollar} resulted in its alteration to marcasite and pyrite. This was followed by precipitation of arsenian pyrite and arsenopyrite. In-situ analysis and ion mapping by SIMS suggest that most of the gold may have precipitated in solid-solution with the arsenian pyrite and arsenopyrite. However, gold was subsequently redistributed, concentrated and crystallized as colloidal and microscopic particles within voids, microfractures and at grain boundaries of the arsenian pyrite, arsenopyrite and trace amounts of other sulphides.;Ankerite-siderite and arsenopyrite geothermometers indicate that mineral deposition occurred from about 400 to 145{dollar}\sp\circ{dollar}C. The lower limit of carbonate formation temperatures suggest that the ambient country-rock temperatures at the time of mineralization were about 145 and 215{dollar}\sp\circ{dollar}C for Bogosu and Prestea ores, respectively. Peak metamorphic temperatures are estimated at {dollar}{lcub}\approx{rcub}375\sp\circ{dollar}C.;Calculated oxygen and carbon-isotope values for the hydrothermal fluid ({dollar}\rm\delta\sp{lcub}18{rcub}O \approx 11.8\pm 1.5\perthous,\ \delta\sp{lcub}13{rcub}C \approx -12.7\ \pm\ 2.2\perthous{dollar}) are consistent with the generation of a metamorphic ore fluid in equilibrium with the Birimian sedimentary rocks. However, lower calculated fluid {dollar}\delta\sp{lcub}18{rcub}{dollar}O and {dollar}\delta\sp{lcub}13{rcub}{dollar} values of 8.1 {dollar}\pm{dollar} 2.0{dollar}\perthous{dollar} and {dollar}-13.8\ \pm\ 3.3\perthous{dollar}, respectively, for quartz and carbonates in mineralized samples suggest that phase separation of the ore fluid to a CO{dollar}\sb2{dollar}-rich gas phase and a residual ore fluid occurred prior to mineralization.;Geological and geochemical evidence suggest that the Ashanti Gold Belt formed in a sediment-dominated accretionary prism similar to the southern coast of Alaska

Comparative study of NETmix and T-jets reactors based on pressure dynamics

Tese de mestrado integrado. Engenharia Química. Universidade do Porto. Faculdade de Engenharia. 201