Nanosilica-enhanced water-based drilling mud for hole cleaning in inclined wells

Inadequate hole cleaning often leads to challenges in drilling operations such as poor cuttings lifting that causes pipe sticking, losing tools, and difficulties in liner/casing placements. Designing a drilling mud with improved rheological properties that are facing minimal degradation under high temperature conditions would be a better solution to increase cuttings transportation efficiency. Static tests which included rheological properties, fluid loss, and fluid flow behaviour of the drilling mud with and without nanosilica were examined according to API standards. This study also involved dynamic tests which investigated the performance of nanosilica in degraded and non-degraded water-based drilling muds to improve cuttings lifting in inclined drilling operations. This research uses a jacketed mixing tank with a capacity of 200 litres and an operating temperature of up to 482? (250?) to degrade drilling mud with and without nanosilica before testing them at ambient condition in a flow loop. Simulated cuttings of irregular shape and sizes ranging from 1.4 to 4.0 mm were used. Different inclination angles (0, 30, 60, and 90°) have been considered in the dynamic tests with and without pipe rotation (120, 150, and 180 rpm) to simulate the drilling conditions in a wellbore. It was found that the presence of nanosilica has increased the cuttings transportation efficiency (CTE) in all experiments. Results indicate that the presence of nanosilica in mud increases the colloidal interactions with cuttings and contributes to improvements in CTE by 30.8 to 44%. At elevated temperatures, 12 ppg muds performed better than 9 ppg muds. However, after adding the optimum concentration of nanosilica of 1.0 ppb (by weight), the CTE improvement for 9 ppg muds was higher than that for the 12 ppg muds. The presence of nanosilica improves the CTE at elevated temperatures because the distribution of nanosilica in the mud is able to withstand the heat in high temperature conditions thus improving CTE when comparing to mud without nanosilica. The introduction of nanosilica in water-based drilling fluids shows promising results in hole cleaning process which will enable them to be used in extended reach drilling operations

Variation over time of the du mortier calibration algorithm for ground-based spectrometer

Having a stable and steady calibration constants increases the likelihood of a spectrometer to perform as expected over a reasonable period of time. The purpose of this paper is to study the variation over time of the Du Mortier calibration algorithm used in a spectrometer for atmospheric condition measurement. This is carried out over a course of six months and the measurements were taken for every minute intervals from 8.30am to 4.30pm in three locations in Kota Kinabalu. By using the improved Langley method, monthly calibration constants for eight wavelengths were determined for Du Mortier model. Results shows that there were statistically significant differences between mean calibration constants when comparing the selected months. However, if only wavelengths of 460nm, 500nm, 540nm, 580nm and 620nm are taken into account, the results say otherwise

Rapid mapping of digital integrated circuit logic gates via multi-spectral backside imaging

Modern semiconductor integrated circuits are increasingly fabricated at untrusted third party foundries. There now exist myriad security threats of malicious tampering at the hardware level and hence a clear and pressing need for new tools that enable rapid, robust and low-cost validation of circuit layouts. Optical backside imaging offers an attractive platform, but its limited resolution and throughput cannot cope with the nanoscale sizes of modern circuitry and the need to image over a large area. We propose and demonstrate a multi-spectral imaging approach to overcome these obstacles by identifying key circuit elements on the basis of their spectral response. This obviates the need to directly image the nanoscale components that define them, thereby relaxing resolution and spatial sampling requirements by 1 and 2 - 4 orders of magnitude respectively. Our results directly address critical security needs in the integrated circuit supply chain and highlight the potential of spectroscopic techniques to address fundamental resolution obstacles caused by the need to image ever shrinking feature sizes in semiconductor integrated circuits

A multi-layer approach to designing secure systems: from circuit to software

In the last few years, security has become one of the key challenges in computing systems. Failures in the secure operations of these systems have led to massive information leaks and cyber-attacks. Case in point, the identity leaks from Equifax in 2016, Spectre and Meltdown attacks to Intel and AMD processors in 2017, Cyber-attacks on Facebook in 2018. These recent attacks have shown that the intruders attack different layers of the systems, from low-level hardware to software as a service(SaaS). To protect the systems, the defense mechanisms should confront the attacks in the different layers of the systems. In this work, we propose four security mechanisms for computing systems: (i ) using backside imaging to detect Hardware Trojans (HTs) in Application Specific Integrated Circuits (ASICs) chips, (ii ) developing energy-efficient reconfigurable cryptographic engines, (iii) examining the feasibility of malware detection using Hardware Performance Counters (HPC). Most of the threat models assume that the root of trust is the hardware running beneath the software stack. However, attackers can insert malicious hardware blocks, i.e. HTs, into the Integrated Circuits (ICs) that provide back-doors to the attackers or leak confidential information. HTs inserted during fabrication are extremely hard to detect since their overheads in performance and power are below the variations in the performance and power caused by manufacturing. In our work, we have developed an optical method that identifies modified or replaced gates in the ICs. We use the near-infrared light to image the ICs because silicon is transparent to near-infrared light and metal reflects infrared light. We leverage the near-infrared imaging to identify the locations of each gate, based on the signatures of metal structures reflected by the lowest metal layer. By comparing the imaged results to the pre-fabrication design, we can identify any modifications, shifts or replacements in the circuits to detect HTs. With the trust of the silicon, the computing system must use secure communication channels for its applications. The low-energy cost devices, such as the Internet of Things (IoT), leverage strong cryptographic algorithms (e.g. AES, RSA, and SHA) during communications. The cryptographic operations cause the IoT devices a significant amount of power. As a result, the power budget limits their applications. To mitigate the high power consumption, modern processors embed these cryptographic operations into hardware primitives. This also improves system performance. The hardware unit embedded into the processor provides high energy-efficiency, low energy cost. However, hardware implementations limit flexibility. The longevity of theIoTs can exceed the lifetime of the cryptographic algorithms. The replacement of the IoT devices is costly and sometimes prohibitive, e.g., monitors in nuclear reactors.In order to reconfigure cryptographic algorithms into hardware, we have developed a system with a reconfigurable encryption engine on the Zedboard platform. The hardware implementation of the engine ensures fast, energy-efficient cryptographic operations. With reliable hardware and secure communication channels in place, the computing systems should detect any malicious behaviors in the processes. We have explored the use of the Hardware Performance Counters (HPCs) in malware detection. HPCs are hardware units that count micro-architectural events, such as cache hits/misses and floating point operations. Anti-virus software is commonly used to detect malware but it also introduces performance overhead. To reduce anti-virus performance overhead, many researchers propose to use HPCs with machine learning models in malware detection. However, it is counter-intuitive that the high-level program behaviors can manifest themselves in low-level statics. We perform experiments using 2 ∼ 3 × larger program counts than the previous works and perform a rigorous analysis to determine whether HPCs can be used to detect malware. Our results show that the False Discovery Rate of malware detection can reach 20%. If we deploy this detection system on a fresh installed Windows 7 systems, among 1,323 binaries, 198 binaries would be flagged as malware

Excellent educare tuition centre / Marsytah Shaari... [et al.]

Committing to the business domain expressly in education directly will help the Ministry Of Education to increase the education level or standard in Malaysia. Barrel to the government’s aspiration is to produce the educated and excellent younger for the new millennium era. That is why we come out with this business in order to overcome the barrel. Apart from that, in order to realize the government's encouragement, to increase the number of excellent students in our country, to increase the quality of education and to produce more expertise and professional in fieldwork, therefore we come out with this business. Based on the objectives of Excellent Educare Tuition Centre, we will provide a space for the USPR, PMR, SPM & STPM candidates and also for those are the former students (repeaters ), to improve their quality of studies. Besides that, we come out with the latest technology approach, meaning that our services are totally technology-oriented. The teachers will conduct the learning session using the projector and laptop. This will be the best way to attract student's attention and will avoid the feeling of the bore during the learning session. These actually comply with our target to establish the best learning condition for the student

Review of synthesis, characteristics and technical challenges of biodiesel based drilling fluids

Acknowledgements The Egyptian authors were supported by Science, Technology & Innovation Funding Authority (STDF) under the grant (30894). The UK's authors would like to acknowledge the financial support from an Institutional Links grant, ID 352343681, under the Newton-Mosharafa Fund partnership. The grant is funded by the UK Department for Business, Energy and Industrial Strategy and delivered by the British Council. We are also grateful to the publishers, journals, and authors who provided their permission for us to reproduce their figures and tables in this review.Peer reviewedPostprin

mTreeIllustrator: A Mixed-Initiative Framework for Visual Exploratory Analysis of Multidimensional Hierarchical Data

Multidimensional hierarchical (mTree) data are very common in daily life and scientific research. However, mTree data exploration is a laborious and time-consuming process due to its structural complexity and large dimension combination space. To address this problem, we present mTreeIllustrator, a mixed-initiative framework for exploratory analysis of multidimensional hierarchical data with faceted visualizations. First, we propose a recommendation pipeline for the automatic selection and visual representation of important subspaces of mTree data. Furthermore, we design a visual framework and an interaction schema to couple automatic recommendations with human specifications to facilitate progressive exploratory analysis. Comparative experiments and user studies demonstrate the usability and effectiveness of our framework

Experimental investigation of hole cleaning in directional drilling by using nano-enhanced water-based drilling fluids

The authors wish to thank the Ministry of Higher Education, Malaysia and Universiti Teknologi Malaysia for funding this project under grants with cost center and reference numbers of Q.J130000.2646.15J52 (PY/2017/01823), Q.J130000.2546.14H83 (PY2016/06266) and R.J130000.7651.4C195 (PY/2018/03001). We are also grateful to Ainuddin Wahid Endowment Fund for providing the necessary support to accomplish this research. Also, the support from the School of Engineering at the University of Aberdeen UK to complete this work is appreciated.Peer reviewedPostprin

Potential of using natural and synthetic binder in wood composites

The physical and mechanical properties of particleboard bonded with different cooking percentages of seaweed (Kappaphycus alvarezii), with different percentages of starch and different percentages of adhesives, and wood plastic composite (WPC) from High-Density Polyethlene (HDPE) with Acacia mangium wood powder were determined in this study. Seaweed mixed with different percentages of sulfuric acid (30%, 50%, 70%) and Sodium Hydroxide (70%, 50%, 30%) were prepared as a binder for particleboard. For a starch-based binder, different percentages of starch (10%, 15%, 20%) were prepared, before producing particleboard with different amounts of binder (20%, 25%, 30%). As for WPC, wood powders were bonded with different percentages of HDPE content (70%, 80%, 90%). Results indicated that WPC at 90% HDPE shows the best performance in the water absorption (0.07%) and thickness swelling test (2.54%). Starch-based particleboard recorded the highest Modulus of Elasticity (MOE) value (1115.07 N/mm2 at 15% starch with 30% amount of binder), while WPC (90% HDPE) and starch-based particleboard (10% starch with 20% amount of binder) both recorded the highest Modulus of Rupture (MOR) at the same value, which is 7.84 N/mm2. Starch-based particleboard has a better internal bond, which is 0.05 N/mm2. However, seaweed-based particleboard has a higher density value, which is 0.6 g/cm3

Late Paleozoic adakites and Nb-enriched basalts from northern Xinjiang, northwest China: evidence for the southward subduction of the Paleo-Asian Oceanic Plate

Abstract Volcanic rocks consisting of adakite and Nb-enriched basalt are found in the early Devonian Tuoranggekuduke Group in the northern margin of the KazakhstanJunggar Plate, northern Xinjiang, northwest China. The geochemical characteristics of the andesitic and dacitic rocks in this area resemble that of adakites. The relatively high Al 2 O 3 , Na 2 O and MgO content and Mg # values indicate that the adakites were generated in relation to oceanic slab subduction rather than the partial melting of basaltic crust. A slightly higher SrI and a lower e Nd (t = 375 Ma) compared to adakites of mid-oceanic ridge basalt (MORB) imply that slab sediments were incorporated into these adakites during slab melting. The Nb-enriched basalt lavas, which are intercalated in adakite lava suite, are silica saturated and are distinguished from the typical arc basalts by their higher Nb and Ti content (high field strength element enrichment). They are derived from the partial melting of the slab melt-metasomatized mantle wedge peridotite. Apparently, positive Sr anomalies and a slightly higher heavy rare earth element content in these adakites compared to their Cenozoic counterparts indicate that the geothermal gradient in the PaleoAsian Oceanic subduction zone and the depth of the Paleo-Asian Oceanic slab melting are between those of their Archean and Cenozoic counterparts. The distribution of the adakites and Nb-enriched basalts in the northern margin of the Kazakhstan-Junggar Plate, northern Xinjiang, indicates that the Paleo-Asian Oceanic Plate subducted southward beneath the Kazakhstan-Junggar Plate in the early Devonian period