Control of a coupled tank system using PI controller with advanced control methods

The liquid level control in tanks and flow control between cascaded or coupled tanks are the basic control problems exist in process industries nowadays. Liquids are to be pumped, stored or mixed in tanks for various types of chemical processes and all these require essential control and regulation of flow and liquid level. In this paper, different types of tuning methods are proposed for Proportional-Integral (PI) controller and are further improved with integration of Advanced Process Control (APC) method such as feedforward and gain scheduling to essentially control the liquid level in Tank 2 of a coupled tank system. The MATLAB/Simulink tools are used to design PI controller using pole-placement, Ciancone, Cohen Coon and modified Ziegler-Nichols tuning method with Cohen Coon tuning method found to have a better performance. Advanced process control such as feedforward-plus-PI, Gain Scheduling (GS) based PI, Internal Model Control (IMC) based PI, feedforward-plus-GS-based PI and feedforward-plus-IMC-based PI controllers are further tested as improvement version to further compare the significance of the advanced process control outcomes hence GS-PI, improved GI-base PI-plus FF found to have better performance. The GS method is built over five operating points to approximate the system’s nonlinearity and is eventually combined with feedforward control to yield a much better performance

The influence of a curved on copper-type down conductor

The objective of this paper is to investigate the influence of curved copper conductor angle under current transient and voltage using numerical analysis approach. A thorough evaluation for copper down-conductor attainable in lightning protection system with a recommended cross-sectional area of conductor based on the standards under different numerous angles will be examined. The results in terms of field values were reviewed and considered in resemblance with the critical breakdown value of air. Although the comparison is by no means rigorous, it may shed some light on how the geometrical modelling and the physical parameters weighted in the computational modelling and how further refinement could be synthesized. In the end, a realistic approach for the optimal angle of down-conductor contributed to the installation design of a down-conductor in confined area is set and establish

Tantangan Pengembangan Padi Dikabupaten Kepulauan Mentawai

This study aims to identify the problems and develop rice agribusiness in Mentawai Islands from upstream to downstream and formulate appropriate policy recommendations to be implemented. The research location determined by purposive namely in the village Makalo and Malakopa District of South Pagai, Sikakap subdistrict Taikako Village, Village Saumanganya District of North Pagai, Bosua Village and Village Beriulou District of South Sipora, Village Rogdog and Madobag District of South Siberut. Respondents in this study were 30 farmers. Respondents farmers selected by simple random sampling method. The results showed that the majority of rice paddies new openings in six districts consist of peatlands with a depth varying from 0.4- > 2.0 meter, fields new openings that have been implemented in the Mentawai Islands in general can not be expected to result in maximum productivity due to problems of land suitability diverse. Farmers also do not take action appropriate technical culture starting from land preparation, seed selection, weeding, fertilizing and water management. Behaviorally agriculture, farmers in Mentawai Islands is not a society that blends with the culture of rice fields, it is because basically their agricultural base is dry land agriculture with farming patterns. This will certainly give a great challenge and not easy for the cultivation of rice in the Mentawai Islands

Preliminary study on Azolla cultivation and characterization for sustainable biomass source

Azolla is a freshwater fern that belongs to the Azollaceae family. It is easy to grow and is highly productive. It can fix atmospheric nitrogen due to the presence of Anabaena azollae. Azolla has been applied to the rice field as a classic fertilizer. It is a good source of protein and contains almost all essential amino acids and minerals. Various research has been done and is still ongoing to determine the capability of Azolla as a phytoremediator and to be used as a sustainable bioenergy source. This preliminary study investigated the ideal environment for Azolla cultivation in Malaysia (humid weather throughout the year with average daily temperature across Malaysia between 21°C and 32°C). To the best of our knowledge, there is no research conducted in Malaysia to study the optimum environment for Azolla cultivation. Therefore, determining the optimum condition for growing Azolla was done by manipulating parameters: water depth, nutrient concentration, pH, and sunlight exposure. Meanwhile, chemical compositions (moisture, crude protein, crude fat, ash, crude fibre, carbohydrate and energy) were determined using proximate analysis. Results obtained showed that Azolla growth was the best in water depth of 20 cm, the nutrient concentration of 812.5 ppm, pH of 7 and under 100% sunlight exposure. Dried Azolla had 6.38% moisture, 27.1% crude protein, 6.37% crude fat, 14.29% ash, 34.29% crude fibre, 45.86% carbohydrate and 349.17 kcal/100 g energy. Based on the result, Azolla cultivated in this experiment could be used as a sustainable biomass source to produce animal feed (high protein content) and bioenergy (high fibre content)

Sisi Gelap Demokrasi: Kekerasan Masyarakat Madani di Indonesia

Salah satu capaian penting reformasi di Indonesia adalah tumbuhnya masyarakat madani (civil society) yang kuat. Namun, beberapa di antara organisasi masyarakat madani yang paling efektif dewasa ini justru adalah kelompok-kelompok Islamis garis-keras yang mendakwahkan intoleransi dan menyebarluaskan kebencian. Di beberapa wilayah, seperti Jawa Barat dan seputar Jakarta, organisasi-organisasi ini terbukti amat memengaruhi agenda kebijakan publik, dengan mendesak pemerintah—baik di tingkat lokal maupun nasional—untuk menerapkan pandangan mereka mengenai moralitas dan pemahaman mereka mengenai ortodoksi. Meskipun mengusung agenda-agenda yang antidemokrasi, semua organisasi di atas justru memanfaatkan ruang-ruang bebas yang disediakan demokrasi. Pertanyaannya, apakah organisasi-organisasi itu tumbuh berjalan seiring dengan meningkatnya konservatisme sosial masyakarat Indonesia, atau karena koneksi-koneksi politik tingkat tinggi yang kuat? Mengapa mereka tampak lebih efektif dalam advokasi mereka dibanding organisasi-organisasi lainnya? Bagaimana demokrasi mengatasi kekuatan-kekuatan anti-demokrasi yang menggerogotinya itu? Bermula dari Nurcholish Madjid Memorial Lecture (NMML) VII (2013), di buku ini Sidney Jones menjawab pertanyaan-pertanyaan di atas dari perspektif teori gerakan sosial. Dia juga mengevaluasi berbagai tawaran yang sudah diajukan untuk “mengatasi” organisasi-organisasi di atas dan memperkuat pluralisme seperti yang pernah disuarakan almarhum Nurcholish Madjid. Aspek-aspek tersebut dibahas lebih lanjut dari berbagai sudut pandang oleh para penanggapnya: Elga Sarapung, M. Najib Azca, Jeremy Menchik, Sana Jaffrey, Titik Firawati, dan Zainal Abidin Bagir. Semuanya menyajikan persoalan dan tantangan yang tidak mudah, namun tetap menjaga harapan akan Perubahan dan perbaikan demokrasi dan masyarakat madani. Buku ini perlu dibaca oleh para pengambil kebijakan, akademisi, aktivis sosial dan siapa pun yang merasa peduli dengan masa depan demokrasi Indonesia

Computational Cancer Biology: An Evolutionary Perspective

ISSN:1553-734XISSN:1553-735

Evaluation of Local Feed Ingredients Based Diets on Growth Performance of African Catfish, Clarias gariepinus

Formulating the right feed based on the requirements of the fish species is the main solver to reduce the high cost of aquaculture production. In formulating suitable diet, factors such as the sustainability or availability of the feed sources used, quality of the feeds and price of raw materials, need to be taken into account as well so that the diets can be formulated at least cost. Low cost diets using local feed ingredients were formulated in pelleted and extruded forms and fed to juvenile African catfish, Clarias gariepinus, to determine their effect on the growth performance of the fish. Two formulations were tested: Diet A - Formula 1 MARDI and Diet B - Formula 2 MARDI, which were formulated to be iso-caloric and iso-nitrogenous with 32 % digestible protein and energy value of 14 MJ/kg. A commercial diet (Diet C) was included as a control. At 15 wk of culture, fish fed diet C showed the highest growth performance in terms of weight gain, feed conversion ratio (FCR) and specific growth rate (SGR). There were no significant differences (P>0.05) found among diets for weight gain and feed intake. However, FCR and SGR of Diet C were significantly better (P<0.05) compared to the experimental diets. The best FCR was recorded in Diet C at 1.17, followed by Diet A (1.42) and Diet B (1.46). Diet C also had the highest SGR with 1.99%/day followed by Diet B (1.70) and Diet A (1.67). Cost of both diets, A and B, was RM 2.50/kg compared to RM 3.50/kg for Diet C. Although the FCR of the commercial feed was lower than the experimental diets, the production cost of fish was RM4.11/kg for the commercial feed compared to RM 3.54-3.65/kg for the experimental diets. It is concluded that local feed ingredients can be used in formulating diets for catfish and they have no detrimental effect on the growth of African catfish

Total phenolic content and antioxidant activities of corchorus capsularis and stevia rebaudiana extracts

The purposes of this study were to determine total phenolic content (TPC) and antioxidant activities of C.capsularis and S.rebaudiana. Methodology: C.capsularis was extracted successively with methanol and chloroform methanol separately while S.rebaudiana was extracted using methanol and chloroform solvent. The plant extracts were used to conduct various antioxidant assays. TPC assay using Folin-Ciocalteu method was used to assess the presence of phenolic compounds in each sample. The extracts samples were also subjected to assess their potential antioxidant activities through DPPH, ABTS and FRAP assay. The present study showed that both methanol extract of C.capsularis and S.rebaudiana had highest TPC, followed by chloroform extract of S.rebaudiana and chloroform methanol extract of C.capsularis. Next, the DPPH radical scavenging assay was found to be higher in the methanol extract of S.rebaudiana at the concentration of 154.67μg/ml. The cation radical scavenging activity, measured by ABTS assay was shown that methanol extract of S.rebaudiana (278μg/ml) had the lowest EC50 as compared to the other samples. Interestingly, among the various samples, the methanol extract of S.rebaudiana demonstrated a very significant antioxidant activity in FRAP assay (p<0.05). The results of the present study showed that all the extract samples contain significantly high phenolic compounds with superior antioxidant activity as evidence by scavenging of free radical including DPPH and ABTS. In conclusion, it is conceivable that the C.capsularis and S.rebaudiana have shown potential as sources of natural antioxidants

Efficiency Droop Of InGaN/GaN Led With Different Indium Composition

III-nitride light emitting diodes (LEDs) have attracted considerable attraction due to their various applications in displays and illumination lighting. Nevertheless, the majority of InGaN/GaN LEDs suffer from the efficiency droop. This droop would limit the potential of the LEDs in high current applications. As widely reported, high indium content in InGaN/GaN multiquantum well active region of the LED promotes indium fluctuation that degrades the efficiency of the LED. In this work, we will present results of the efficiency droop for InGaN/GaN LED with indium content of 18% and 8%, respectively. The efficiency droop of the LED with 18% of indium shows higher efficiency droop than the LED with 8% of indium content

Effect Of Nucleation Time With TMAl Preflow Assistance On Reducing Dislocation Density Of Aln Layer For

AlGaN-based UVC LEDs have now received numerous attentions due to their ability to eliminate coronaviruses which cause COVID-19 disease. It is therefore essential to improve the efficiency of the LEDs to make them compatible for large scale applications. One of the major challenges to improve the efficiency is to reduce the dislocation density in AlN layer; the base layer for the LEDs, to be below 109 cm-2. Thus far, many works have been proposed to reduce the dislocation in the AlN layer. However, by properly adjusting the AlN nucleation time in the growth of the AlN layer, the dislocation can be reduced. The effect might be more significant with TMAl preflow assistance, which is applied after the growth of the nucleation. In this work, we will present the effect of the nucleation time with the assistance of TMAl preflow on reducing the dislocation density in the overgrown AlN layer. With 60 seconds of nucleation, the density of the dislocation in the AlN layer can be as low as 9.0 x 108 cm-2. In addition. the role of the TMAl preflow assistance will be justified. The AlN layer was subsequently used to grow a 255 nm UVC LED. The diode characteristic and CL emission of the LED will be discussed towards the endof the presentation