84 research outputs found
Gaze Puisi “At Ta’syirah” Hisyam Al Jakh
No full textPenelitian ini bertujuan membahas konsep gaze Hisyam Aljakh dengan perspektif Slavoj Žižek. Diskursus mengenai gaze dalam karya sastra menyangkut narasi representasi subjek pengarang dari eksterioritas simbolisnya. Representasi dari the other ini mengindikasikan adanya ideologi tertentu pada pengarang yang sudah terkonstruksi secara sistemik dan direpresentasikan melalui uraiannya. Penjelmaan simbolis the other terhadap ideologi pengarang membuatnya terjerembap pada tataran simbolis, kemudian menjadikannya sebagai objek penyebab hasrat. Dalam konteks penelitian ini, gaze memperlihatkan bagaimana upaya yang dilakukan pengarang untuk memperlihatkan subjektivitasnya menuju posisi the real. Interpelasi the other terhadap subjek pengarang diperlihatkan dalam puisi “Atta’syirah” karya Hisyam Aljakh yang mengilustrasikan adanya konstruksi simbolis dari eksternal pengarang. Dengan metode analisis tekstual dan identifikasi konstruksi simbolis, penelitian ini menghasilkan temuan bahwa gaze berhasil mengkonstruksi ideologi pengarang dengan perjumpaan simbolis yang merepresentasikan eksternalnya sekaligus menunjukkan bahwa tulisan itu merupakan representasi dari tatanan simbolisnya.[Hisyam Aljakh’s Gaze in "Atta’syirah"] This research discusses the gaze concept of Hisyam Aljakh with Slavoj Žižek’s perspective. The discourse on gaze in literary works concerns the author’s narration of his subject representation and symbolic exteriority. This representation of the other indicates a the author’s certain ideology which is already systematically constructed and represented through the author’s explanation. The symbolic embodiment of the other on the author’s ideology brings it into the symbolic order, and subsequently makes it the object of desire. In this research, gaze illustratesthe author’s effort to expose his subjectivity leading to the real position. The interpellation of the other on the author’s subject is portrayed on the poem of “Atta’syirah” by Hisyam Aljakh which illustrates the symbolic construction external to the author. With the textual analysis method and symbolic construction identification, this research found that the existence of gaze successfully constructs the author's ideology with a symbolic encounter that represents the external as well as revealsthat the writing isa representation of the symbolic order.Keywords: gaze; subjectivity; symbolic construction; Atta’syirah; Slavoj Žiže
KINETIKA REAKSI KHROM DAN KAPUR PADAM PADA PENGOLAHAN LIMBAH PENYAMAKAN KULIT SECARA BATCH
No full textKulit merupakan bahan baku untuk produk-produk kerajinan. Sebelum digunakan, kulit melalui proses
penyamakan. Sebagaian besar industri penyamakan kulit menggunakan khrom sebagai bahan penyamak.
Untuk limbah penyamakan kulit yang mengandung khrom, kadar maksimum yang diperbolehkan sebesar
2,0 mg/L. limbah yang dihasilkan perlu ditangani agar tidak menimbulkan masalah lingkungan.
Pemungutan khrom dari limbah cair penyamakan kulit dapat dilakukan dengan mereaksikan dengan
kapur padam. Namun kondisi dan kinetika reaksinya belum diketahui secara baik, khususnya reaksi
dalam reaktor batch, sehingga perlu dipelajari. Reaksi pemungutan khrom dengan kapur padam dapat
dilakukan dalam reaktor slurry tangki berpengaduk secara batch. Mula-mula limbah penyamakan kulit
dimasukan kedalam reaktor kemudian diaduk dengan kecepatan tertentu pada suhu kamar. Pada
kondisi reaktor telah tercapai kemudian dimasukan kapur padam. Cuplikan diambil setiap selang waktu
3 menit selama 24 menit..Analisis konsentrasi khrom yang tertinggal dijalankan dengan Atomic
Absorrption Spectrofhotometer (AAS). Variable yang dipelajari adalah variasi kecepatan pengaduk pada
kisaran 140-200 rpm, suhu 30 –60 C, dan perbandingan mol kapur padam dengan mol khrom 1 – 3.
Hasil penelitian menunjukkan bahwa reaksi antara kapur padam dengan khrom secara keseluruhan
dikendalikan oleh perpindahan massa pada lapisan film cair dan lapisan hasil. Pada suhu 30 – 60 C,
konstanta kecepatan reaksi mengikuti persamaan Arrhenius. Kenaikan suhu pada rentang tersebut tidak
berpengaruh besar pada nilai difusivitas pada lapisan hasil. Perbandingan mol kapur padam dengan
khrom tidak mempengaruhi konstanta perpindahan massa pada lapisan film cair, difusivitas pada lapisan
hasil maupun konstanta kecepatan reaksi
Design and operation of multivessel batch distillation
No full textDistillation processes in chemical industries have shown significant roles for separating valuable compounds from a mixture. In a specific separation process like separation of perfumes, essential oils, and pharmaceutical products, batch distillation is somehow preferable than continuous one. Batch distillation, however, in these separation processes is advantageous, particularly in the flexibility of fluctuating concentration of feed and products, and in changing production capacity based on market demand. In addition, the separation can be performed in only single batch distillation column for all the changing conditions. Due to the dynamic behavior of the operation of batch distillation that leads to more difficult operation, such efforts have been done to attain the desired specifications and, at the same time, to increase the operability. The efforts include both the design and operation of batch distillation. This research focuses on the investigation of separation behavior of multivessel batch distillation for multicomponent mixtures. The distillation unit used in this research consists of two columns with a vessel between the columns, a reflux vessel on the top of the column, and a reboiler (still pot). The experimental data are validated by simulation. Several cases of separation processes are represented by case studies as follows: Top product recovery, removal of light and heavy impurities, and removal of middle boiling component. By using an ideal ternary mixture consisting of ethanol, 1-propanol, and n-butanol, the case studies were used to investigate the separation behavior. It is found that for the case of top product recovery, increasing the vessel holdup of the middle vessel did not make a significant effect to the increase of ethanol purity in top vessel. However, an increase of ethanol purity in top vessel was obtained by simultaneously increasing the middle vessel holdup and reducing the holdup of top vessel. In this case, reducing the top vessel holdup of 50% results in the maximum achievable ethanol purity in top vessel of 96%. For the case of removal of light and heavy impurities, the concern was on the trade-off between product purity and product recovery. An agreement was found to have 91% purity of 1-propanol in the middle vessel with recovery of 74%. However, if it is desired to produce high purity product with suffering on the product recovery, reprocessing the top and bottom product can be carried out to recover the middle component in another batch. In addition, for the case of removing a middle boiling component from a mixture, increasing the middle vessel holdup did not give significant effect to the ethanol purity in top vessel. This may, therefore, be uneconomical to carry out since it leads to more losses of ethanol in middle vessel. An additional investigation on an introduction of slop vessels in the operation of multivessel batch distillation was also discussed in this thesis through simulation works. For the case studies discussed, it is found that slop vessel holdup and slop vessel position simultaneously give significant effects on the product purity of respective vessels
Responsible Mineral Resource Development: The Way Forward
No full textThis paper provides an insight to a responsible mining, whereby it is an effective application of sustainability concepts to the full mining life cycle. Responsible mining refers to advocacy to reform mining activity, as well as to a marketing strategy used by mining companies to promote their operations as environmentally or socially sound. The author explains the ASEAN principles of responsible mineral resource development, the reporting mechanism and criteria in ASEAN countries responsible mining framework
Modeling and simulation of steady state model approach for horizontal three phase separator (HTPS)
No full text
A New Approach to the Identification of Distillation Column Based on Hammerstein Model
No full textDeveloping a suitable nonlinear model is the most challenging problem in the application of nonlinear model based controllers to distillation column. Hammerstein model consists of a nonlinear static element described by wavenet based nonlinear function, followed by a linear dynamic element described by the Output Error(OE) model was used in this study to represent the nonlinear dynamics of the distillation column. The model parameters were identified using iterative prediction-error minimization method. The model validation results proved that the Hammerstein model was capable of capturing the nonlinear dynamics of distillation column
Study of Important Operating Parameters for the Adsorption of Acrylic Acid from Wastewater Using Palm Ash
No full textThe potential of the agriculture waste residue, palm ash as an adsorbent to remove Acrylic Acid (AA) was investigated in the present study was identified. Palm ash was treated by reflux with sulfuric acid before the adsorption. Batch adsorption study was conducted to study the effect of various operating parameters such as adsorbent dosage, initial concentration of AA, temperature and contact time. The experimental data were correlated to the Langmuir and Freundlich models of adsorption. Isotherm data were fitted well with Freundlich model. The maximum adsorption capacity of AA onto palm ash was obtained as qm = 1.98 mg g-1 with an optimum palm ash dosage w = 200 g L-1 at 303K for C0 = 100 mg L-1. The results indicate that palm ash is suitable as adsorbent to remove AA from aqueous solutions
Modeling and Simulation Study of an Industrial Radial Moving Bed Reactor for Propane Dehydrogenation Process
No full textAn accurate model is required to optimize the propane dehydrogenation reaction carried out in the radial moving bed reactors (RMBR). The present study modeled the RMBR using a plug flow reactor model incorporated with kinetic models expressed in simple power-law model. Catalyst activity and coke formation were also considered. The model was solved numerically by discretizing the RMBR in axial and radial directions. The optimized kinetic parameters were then used to predict the trends of propane conversion, temperature, catalyst activity and coke content in the RMBR along axial and radial directions. It was found that the predicted activation energies of the propane dehydrogenation, propane cracking and ethylene hydrogenation were in reasonable agreement with the experimental values reported in the literature. The model developed has accurately predicted the reaction temperature profile, conversion profile and catalyst coke content. The deviations of these simulated results from the plant data were less than 5%
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