Ablation of Oil-Sand Lumps in Hydrotransport Pipelines

Oil-sand ore is a kind of heavy crude oil found primarily in Canada. The surface mining of this petroleum resource requires expensive 400-ton capacity trucks to transport the ore to the slurry plant. The slurry prepared with the crushed ore is usually conditioned in a hydrotransport pipeline prior to extracting bitumen. As the elimination of the mammoth trucks has a tremendous economic and environmental incentive, it is of industrial interest to employ new processes capable of conditioning oil-sand right at the mine face. This would demand an accelerated rate of conditioning compared to what is achieved at present in the industry. One of the significant steps of the conditioning process is oil-sand lump ablation (OSLA). An understanding of the fundamental concepts associated with OSLA is essential to achieve any industrial-scale change in the current conditioning method. A number of parameters such as temperature, lump size, pipe diameter, pipe length, flow rate, and shear influence the ablation process. The current chapter introduces the concept of OSLA. It also includes a comprehensive review of the most important models available to predict the ablation rate and the scope of future works

Modeling Friction Losses in the Water-Assisted Pipeline Transportation of Heavy Oil

In the lubricated pipe flow (LPF) of heavy oils, a water annulus acts as a lubricant and separates the viscous oil from the pipe wall. The steady state position of the annular water layer is in the high shear region. Significantly, lower pumping energy input is required than if the viscous oil was transported alone. An important challenge to the general application of LPF technology is the lack of a reliable model to predict frictional pressure losses. Although a number of models have been proposed to date, most of these models are highly system specific. Developing a reliable model to predict pressure losses in LPF is an open challenge to the research community. The current chapter introduces the concept of water lubrication in transporting heavy oils and discusses the methodologies available for modeling the pressure drops. It also includes brief descriptions of most important pressure loss models, their limitations, and the scope of future works

ANALISIS PUTUSAN BEBAS OLEH HAKIM PENGADILAN NEGERI TANJUNGKARANG TERHADAP BANDAR SABU YANG MELAKUKAN TINDAK PIDANA PEREDARAN GELAP NARKOTIKA (Studi Putusan Nomor 13/Pid.Sus/2022/PN.Tjk)

Ditengah upaya dalam pemberantasan narkotika yang dilakukan oleh penegak hukum, terdapat salah satu putusan yang memicu kontroversi dan menarik untuk dibahas yaitu pada Putusan Pengadilan Negeri Tanjungkarang Nomor 13/Pid.Sus/2022/PN.Tjk karena Majelis Hakim Pengadilan Negeri memutus untuk membebaskan terdakwa bernama Muhammad Sulton yang didakwa melakukan tindak pidana narkotika menjadi otak dalam tindak pidana pemufakatan jahat melakukan pengedaran narkotika golongan I jenis sabu. Adapun putusan dalam perkara ini berbanding terbalik dengan dakwaan Jaksa Penuntut Umum yang menuntut hukuman mati dan denda sebesar Rp.10.000.000.000,- (sepuluh milyar rupiah). Dalam menjatuhkan putusan Majelis Hakim dalam memutus perkara atas dasar pertimbangan yuridis diantaranya keterangan terdakwa, keterangan saksi serta dakwaan Jaksa Penuntut Umum namun pada proses pembuktian Jaksa Penuntut Umum tidak bisa menunjukkan bukti yang kuat dan meyakinkan Hakim bahwa terdakwa telah melanggar Pasal 114 dan Pasal 112 UU Narkotika sebagaimana dalam dakwaan, sehingga hakim memutus terdakwa dengan putusan bebas. Tujuan yang hendak dicapai adalah untuk mengetahui dasar pertimbangan hakim serta proses pembuktian terhadap putusan bebas yang dijatuhkan oleh Majelis Hakim dengan menggunakan jenis penelitian yuridis normatif, dan metode pendekatan menggunakan pendekatan perundang-undangan serta pendekatan kasus. Dalam analisis penelitian karena tidak adanya bukti yang cukup dihadirkan oleh Jaksa Penuntut Umum dengan demikian Hakim tidak memiliki keyakinan yang cukup akan keterlibatan terdakwa dengan ditemukannya narkotika tersebut dan sesuai dengan in dubio pro reo yang artinya Hakim ketika memutus perkara tidak boleh ada keragu-raguan dan jika ada keraguan maka hal yang menguntungkan bagi terdakwa yaitu dibebaskan dari dakwaan. Hal ini dikarenakan barang bukti berupa handphone yang diajukan dalam persidangan Jaksa Penuntut Umum tidak mampu menghadirkan bukti berupa percakapan antara terdakwa dengan kurir dari tindak pidana narkotika tersebut. Akibatnya hukum yang didapatkan pada Putusan Nomor 13/Pid.Sus/2022/PN.Tjk ialah adanya putusan bebas akibat pembuktian yang belum sempurna. Kata Kunci: Narkotika, Putusan Bebas, Pertimbangan Hakim, Pembuktia

Receding Horizon Optimization in Haar Domain for Unconstrained Linear Time-invariant Systems

The focus of this study is on developing Haar wavelet based Model Predictive Controller (MPC) for linear unconstrained systems. The problem of computation load in MPC has been addressed. By utilizing the structure of the Haar transformation, the coefficients that construct the first control input in the prediction horizon of the MPC are isolated. Considering only these coefficients, Haar based optimization procedure has been modified. The performance and computational load are compared with those of a Dynamic Matrix Controller (DMC) for a velocity regulation problem of a DC motor. Using the proposed modified Haar based MPC, position and orientation control of a two link planar robot and a wheeled mobile robot are provided as examples toreinforce the discussions.Modifications in the Haar based MPC reduced the amount of computation necessary to construct the first control action in the prediction horizon. Despite the modification and reduction in computation, the controller could handle sudden changes in setpoint, which was depicted in a velocity regulationof a DC motor. For increase in the size of prediction horizon beyond 26 time steps, Haar based MPC requires less computation than DMC. Large prediction horizons provide more stability, less aggressive control action and smoother response for the Haar based MPC.Mechanical Engineerin

Pulsed Free Space Photonic Vector Network Analyzers

Terahertz (THz) radiation (0.1–10 THz) has demonstrated great significance in a wide range of interdisciplinary applications due to its unique properties such as the capacity to penetrate optically opaque materials without ionizing effect, superior spatial resolution as compared to the microwave domain for imaging or ability to identify a vast array of molecules using THz fingerprinting. Advancements in generation and detection techniques, as well as the necessities of application-driven research and industry, have created a substantial demand for THz-range devices and components. However, progress in the development of THz components is hampered by a lack of efficient and affordable characterization systems, resulting in limited development in THz science and technology. Vector Network Analyzers (VNAs) are highly sophisticated well-established characterization instruments in the microwave bands, which are now employed in the lower end of the THz spectrum (up to 1.5 THz) using frequency extender modules. These modules are extremely expensive, and due to the implementation of hollow metallic waveguides for their configuration, they are narrowband, requiring at least six modules to achieve a frequency coverage of 0.2–1.5 THz. Moreover, they are susceptible to problems like material losses, manufacturing and alignment tolerances etc., making them less than ideal for fast, broadband investigation. The main objective of this thesis is to design a robust but cost-effective characterization system based on a photonic method that can characterize THz components up to several THz in a single configuration. To achieve this, we design architectures for the Photonic Vector Network Analyzer (PVNA) concept, incorporating ErAs:In(Al)GaAs-based photoconductive sources and ErAs:InGaAs-based photoconductive receivers, driven with a femtosecond pulsed laser operating at 1550 nm. The broadband photonic devices replace narrowband electronic ones in order to record the Scattering (S)-parameters in a free space configuration. Corresponding calibration and data evaluation methods are also developed. Then the PVNAs are configured, and their capabilities are validated by characterizing various THz components, including a THz isolator, a distributed Bragg Reflector, a Split-Ring Resonator array and a Crossed-Dipole Resonator (CDR) array, in terms of their S-parameters. The PVNAs are also implemented to determine the complex refractive index or dielectric permittivity and physical thickness of several materials in the THz range. Finally, we develop an ErAs:In(Al)GaAs-based THz transceiver and implement it in a PVNA configuration, resulting in a more compact setup that is useful for industrial applications. The feasibility of such systems is also verified by characterizing several THz components. The configured systems achieve a bandwidth of more than 2.5 THz, exceeding the maximum attainable frequency of the commercial Electronic Vector Network Analyzer (EVNA) extender modules. For the 1.1-1.5 THz band, the dynamic range of 47-35 dB (Equivalent Noise Bandwidth (ENBW) = 9.196 Hz) achieved with the PVNA is comparable to the dynamic range of 45-25 dB (ENBW = 10 Hz) of the EVNA. Both amplitude and phase of the S-parameters, determined by the configured PVNAs, are compared with simulations or theoretical models and showed excellent agreement. The PVNA could discern multi-peak and narrow resonance characteristics despite its lower spectral resolution (∼3-7 GHz) compared to the EVNA. By accurately determining the S-parameters of multiple THz components, the transceiver-based PVNA also demonstrated its exceptional competence. With huge bandwidth and simpler calibration techniques, the PVNA provides a potential solution to bridge the existing technological gap in THz-range characterization systems and offers a solid platform for THz component development, paving the way for more widespread application of THz technologies in research and industry

Characterization of a Crossed Dipole Resonator Array using a Pulsed Free Space Two-Port Photonic VNA

We demonstrate a Photonic Vector Network Analyzer (PVNA) capable of measuring a complete set of scattering parameters within the frequency range of 0.2 – 2 THz. The PVNA shows superiority in terms of bandwidth compared to electrical VNAs and is also free from the errors introduced by standing waves, metal waveguides, misaligned flanges, and features less stringent requirements on rigorous and time-consuming calibration routines. As a proof of principle, we characterize a crossed dipole resonator array using the free space two-port PVNA

Terahertz Time-Domain Spectroscopy Based on Commercially Available 1550 nm Fabry–Perot Laser Diode and ErAs:In(Al)GaAs Photoconductors

THz time-domain spectroscopy (TDS) is a promising tool for quality control purposes in industrial applications, but the high cost and the relatively large laser sources still make it difficult to use the full potential of the technology for a decent price. In this work, a THz TDS system, which uses a commercially available Fabry–Perot laser diode emitting at 1550 nm, is presented. By dispersion compensation, pulses with a duration of 544 fs were generated, resulting in THz radiation with a bandwidth of 1.4 THz and a peak dynamic range of 56 dB with state-of-the-art ErAs:In(Al)GaAs photoconducting antennas. These results are compared with those of a conventional and expensive fiber laser system with a 90 fs pulse duration

A Comparison of Continuous-Wave and Pulsed Free Space 2-Port Photonic Vector Network Analyzers for Terahertz Characterization

Photonic Vector Network Analyzers (PVNA) provide a viable solution to the rising demand for efficient, accurate, and affordable characterization instruments for benchmarking terahertz devices and components. This paper compares continuous-wave and pulsed versions of the free space 2-port PVNA and their aptitudes for THz characterization using a distributed Bragg reflector as an application example