716 research outputs found
Porous Metal-Organic Framework CUK-1 for Adsorption Heat Allocation toward Green Applications of Natural Refrigerant Water
No full textThe development of new water adsorbents that are hydrothermally stable and can operate more efficiently than existing materials is essential for the advancement of water adsorption-driven chillers. Most of the existing benchmark materials and related systems in this field suffer from clear limitations that must be overcome to meet global requirements for sustainable and green energy production and utilization. Here, we report the energy-efficient water sorption properties of three isostructural metal-organic frameworks (MOFs) based on the simple ligand pyridine-2,4-dicarboxylate, named M-CUK-1 [M3(μ3-OH)2(2,4-pdc)2] (where M = Co2+, Ni2+, or Mg2+). The highly hydrothermally stable CUK-1 series feature step-like water adsorption isotherms, relatively high H2O sorption capacities between P/P0 = 0.10-0.25, stable cycling, facile regeneration, and, most importantly, benchmark coefficient of performance values for cooling and heating at a low driving temperature. Furthermore, these MOFs are prepared under green hydrothermal conditions in aqueous solutions. Our joint experimental-computational approach revealed that M-CUK-1 integrates several optimal features, resulting in promising materials as advanced water adsorbents for adsorption-driven cooling and heating applications.</p
Aneuploidy in the CUK strains.
No full text<p>The heatmap shows chromosomal copy number for all 36 chromosomes across the 12 CUK strains, based on normalized chromosome read-depth. Copy number varies from disomic (light yellow) to pentasomic (dark-red).</p
Optimasi Sistem Photovoltaik Menggunakan Cuk Konverter Berbasis Simple Perturb and Observe Method
No full textMengingat indonesia merupakan negara tropis, ketersediaan energi matahari cukup melimpah di Indonesia karena musim kemarau berlangsung selama 6 bulan. Photovoltaik juga dapat digunakan sebagai sumber energi listrik di daerah terpencil yang masih belum terjangkau oleh PLN. Rancangan Cuk konverter dipilih karena mampu menurunkan dan menaikkan tegangan sumber dari photovoltaik 200WP. Kelebihan cuk konventer mampu mengurangi ripple pada keluaran PV yang dapat menyebabkan tegangan akan lama mencapai konstan. Metode MPP tracking yang terkenal adalah metode perturb and observe (P&O). PWM digunakan untuk mengontrol konverter dan mengontrol tegangan yang di inginkan. Hasil pengujian tegangan masukan power supply 12V. dengan duty cycle 10% menghasilakan tegangan 1.99V. Sementara hasil pengujian masukan power supply 12V, dengan duty cycle 60% menghasilkan tegangan 11.59V. Penerapan P&O pada cuk konverter dirasa cukup efektif pada sistem photovoltaik dengan hasil yang cukup stabil dengan rata-rata keluaran tegangan 23,848 Volt.
Kata kunci: Photovoltaik, Cuk Konverter, PWM, P&O
AC-DC Cuk converter for power quality improvement of vector controlled PMSM drive
No full textThis paper deals with the analysis, design and digital signal processor (DSP) based hardware implementation of a high frequency isolated AC-DC Cuk converter in discontinuous current mode (DCM) of operation used for power quality improvement at AC mains in vector controlled permanent magnet synchronous motor (PMSM) drive. The design of the Cuk converter is presented to feed the voltage source inverter (VSI) of a vector controlled PMSM drive system. Modeling and simulation is carried out in a standard PSIM software environment. Test results are obtained on DSP based hardware implemented AC-DC Cuk converter fed PMSM drive to demonstrate the improvement in the power quality at AC mains
CUK DÖNÜŞTÜRÜCÜNÜN TASARIMI, DİNAMİK ANALİZİ VEDENETİMİ
No full textGünümüzde artan enerji ihtiyacınıkarşılamak üzere yenilenebilir enerji kaynakları kullanılmaktadır. Güneş enerjisi, hidroelektrik enerji,jeotermal enerji ve rüzgâr enerjisi yoğun olarak kullanılan yenilenebilirenerji kaynaklarındandır. Fosil yakıtların tükenmesi ve çevreye verdiklerizararlardan dolayı gelecek nesillerin enerji talebini karşılamak amacıyla çevredostu yenilenebilir enerji kaynakları kullanılmaktadır. Ülkemizin güneşenerjisi potansiyelinin fazla olması bu alandaki yatırımları her geçen günartırmaktadır. 2018 yılı verilerine bakıldığında Türkiye’nin toplam enerjiihtiyacının %2,6’lık kısmının güneş enerjisi santrallerinden karşılandığıgörülmektedir. Güneş enerjisi fotovoltaik (PV) hücreler tarafından elektrikenerjisine çevrilir. PV hücrelerin birleşmesiyle PV paneller oluşur. PVpanellerin çıkış gerilimleri genellikle ayarsız doğru akım (DA) gerilimdir. Buyüzden bu ayarsız gerilimin ayarlı gerilime dönüştürülmesi gerekmektedir. Enerji sistemlerinde istenilengerilim değerleri DA gerilim üreten güç kaynakları tarafından her zamankarşılanmayabilir. Bu yüzden arzu edilen gerilim seviyelerini karşılayabilmekiçin DA-DA dönüştürücüler tasarlanır. Bu dönüştürücüler arasında yaygın olarakkullanılan topolojilerden birisi de hem düşürücü hem de yükseltici özelliğiolan, düşük çıkış dalgalanma voltajına sahip alçaltıcı ve yükselticidönüştürücülerin birleştirilmesiyle oluşan CUK dönüştürücülerdir. Budönüştürücülerin diğer dönüştürücülerden farkı enerji transferi içinkondansatör kullanmasıdır.Bu amaçla çalışmada PVsistemlerde çıkış geriliminin arzu edilen seviyede ayarlı DA gerilimedönüştürmek için bir CUK dönüştürücü devresi tasarlanmıştır. Çalışma kapsamındaöncelikle CUK dönüştürücünün dinamik modeli anahtarlama elemanının iletim vekesim durumuna göre oluşturulmuştur. Tasarlanan bu CUK dönüştürücü devresineoransal-integral (PI) denetleyici uygulanmıştır. PI denetleyici tasarlanırkenmümkün olabilen en asgari süre ve en az yüzde aşım dikkate alınmıştır.Tasarlanan bu denetleyici yapısı ile CUK dönüştürücü çıkış gerilimi kontroledilmeye çalışılmıştır. Simülasyon çalışmalarında CUK dönüştürücü çıkışgeriliminin 0.06 saniyede istenilen referans değeritakip ettiği gözlemlenmiştir. Simülasyonlar MATLAB/SIMULINK programıkullanılarak gerçekleştirilmiştir. Renewable energy sources are usedto meet the increasing energy demand nowadays. Solar energy, hydroelectricenergy, geothermal energy and wind energy are among the extensively usedrenewable energy sources. Due to the depletion of fossil fuels andenvironmental damage that fossil fuels cause, environmentally friendlyrenewable energy sources are used to meet the energy demand of futuregenerations. Investments in the solar energy field in Turkey increases day byday thanks to the high potential of solar energy in the country. 2.6% portionof the Turkey's total energy needs are met by solar power plants as seen in the2018 year energy consumption data. Solar energy is converted into electricalenergy by photovoltaic (PV) cells. PV panels are formed by merging PV cells.The output voltages of PV panels are usually non-adjustable direct current (DC)voltage. So this non-adjustable voltage must be converted to the adjustable outputvoltage.The desired voltage values inenergy systems may not always be met by the DC voltage generating powersupplies. Therefore, DC-DC converters are designed to meet the desired voltagelevels. One of the most commonly used topologies among these converters is theCuk converters, which are formed by combining buck and boost converters withlow output ripple voltage, which are both buck and boost. The difference ofthese converters from other converters is that they use capacitors for energytransfer.For this purpose, a CUK convertercircuit has been designed to convert the output voltage to the adjustable DCvoltage at the desired level in PV systems. In the scope of this study, thedynamic model of the CUK converter is formed according to the transmission andcutting condition of the switching element at the first hand.Proportional-Integral (PI) controller structure is applied to the designed CUKconverter circuit. When designing the PI controller, the minimum settling time andthe minimum percentage exceeding are considered. With this designed controllerstructure, CUK converter output voltage is tried to be controlled. In thesimulation studies, it was observed that the CUK converter output voltagefollows the desired reference voltage in 0.06 sec. Simulations were performedusing MATLAB / SIMULINK program.</p
Highly selective adsorption of p-xylene over other C-8 aromatic hydrocarbons by Co-CUK-1: a combined experimental and theoretical assessment
No full textHigh quality crystalline Co-CUK-1 can be synthesized rapidly and efficiently by a microwave-assisted method. The resulting microporous coordination material is a highly effective adsorbent for the separation of xylene isomers and ethylbenzene, as demonstrated here through sorption isotherm analysis, Ideal Adsorbed Solution Theory (IASI) calculations, and grand canonical Monte Carlo (GCMC) simulations. Co-CUK-1 showed high sorption capacity and high adsorption selectivity for p-xylene over the corresponding m- and o-isomers, and ethylbenzenes. According to the data obtained from IAST and GCMC simulations, the Co-CUK-1 is found to strongly favour p-xylene adsorption because p-xylene molecules undergo well-defined molecular packing in the 1-D channels; by comparison, the packing efficiencies of o-xylene, m-xylene and ethylbenzene are significantly lower, as is evidenced by lower saturation capacities
Modified CUK Converter with Two Switched Inductor Module Configurations for Photovoltaic Application:Part-II
No full textA new member of Modified CUK Converter family with a two-switched inductor module (MCCSI): Modified CUK Converter with XYL configuration (MCCSI-XYL), Modified CUK Converter with LYZ configuration (MCCSI-LYZ) and Modified CUK Converter with XLZ configuration (MCCSI-XLZ) is introduced in this paper. The highlighting points of the proposed converters are (i) single switch topologies, (ii) continuous input current, (iii) high voltage gain, and (iv) inverted output. The voltage gain analysis of three configurations is carried out in detail. Additionally, the comparison of the three converters is made w.r.t. the component count and voltage gain. The MatLab simulation results meet the mathematical analysis and validate the functionality and feasibility of the presented three converters
Benefits of the Coupled Inductors Combined Cuk-SEPIC (CI-CCS) Converter
No full textAn enhanced DC-DC converter is proposed in this paper, based on the combination of the Cuk and SEPIC converters. This converter uses a single switching node which is common to both Cuk and SEPIC energy transfer stages. The converter uses only one switch, yet provides dual outputs in the form of a bipolar DC bus with a common ground. Since the switch is grounded, a simple, non-isolated gate driver may be used. The proposed converter uses integrated magnetics cores to couple the input and output inductors, which significantly reduces the input current ripple. The new converter is referred to as the Coupled Inductors Combined Cuk-SEPIC (CI-CCS) converter
¬MPPT Pada Sistem PV Menggunakan Algoritma Firefly dan Modified P&O dengan Konverter Hybrid Cuk terkoneksi ke Grid Satu Phasa di Bawah Kondisi Partial Shaded
No full textAbstrak— Photovoltaic (PV) merupakan sumber energi terbarukan yang paling banyak dijumpai di alam serta merupakn energi alternatif yang sangat pesat perkembangannya. Untuk mengahasilkan daya, sebuah PV dipengaruhi sebuah nilai intensitas cahaya matahari yang mengenainya. Sebuah sistem PV membutuhkan sebuah kontrol yang bertujuan untuk meningkatkan efisien daya PV tersebut. Kontrol ini adalah Maximum Power Point Tracking (MPPT) yang dapat mengoptimalkan daya yang dihasilkan oleh PV. Sebuah PV hanya menghasilkan nilai tegangan yang rendah, untuk itu perlu menggunakan koverter DC-DC step up untuk menaikan rasio tegangan DC tadi. Untuk mengoptimalkan sistem ini, diperlukan sebuah konverter yang efisien dan dapat menghasilkan rasio konversi tegangan yang tinggi. Pada penelitian menggunakan firefly algoritm (FFA) dan modified perturb and observe (P&O) sebagai MPPT untuk mendapatkan nilai daya optimal pada keluaran PV. Konverter DC-DC yang digunakan adalah hybrid cuk converter boost mode yang memiliki rasio tegangan yang tinggi. Dari DC-link kemudian masuk ke inverter (VSI) yang diinterkoneksi dengan grid menggunakan current control. Hasil analisis simulasi menunjukan bahwa FFA dan P&O mampu menghasilkan daya PV yang optimum dengan riak yang kecil dan konverter hybrid cuk converter boost mode dapat menghasilkan rasio tegangan yang lebih besar dibandingkan konverter cuk biasa. Kata Kunci — PV, MPPT FFA, MPPT P&O, Hybrid Cuk Converter, DC-Link, Inverter Grid Connected</p
¬MPPT pada Sistem PV Menggunakan Algoritma Firefly dan Modified P&O dengan Konverter Hybrid Cuk Terkoneksi ke Grid Satu Phasa di Bawah Kondisi Partial Shaded
No full text— Photovoltaic (PV) merupakan sumber energi terbarukan yang paling banyak dijumpai di alam serta merupakn energi alternatif yang sangat pesat perkembangannya. Untuk mengahasilkan daya, sebuah PV dipengaruhi sebuah nilai intensitas cahaya matahari yang mengenainya. Sebuah sistem PV membutuhkan sebuah kontrol yang bertujuan untuk meningkatkan efisien daya PV tersebut. Kontrol ini adalah Maximum Power Point Tracking (MPPT) yang dapat mengoptimalkan daya yang dihasilkan oleh PV. Sebuah PV hanya menghasilkan nilai tegangan yang rendah, untuk itu perlu menggunakan koverter DC-DC step up untuk menaikan rasio tegangan DC tadi. Untuk mengoptimalkan sistem ini, diperlukan sebuah konverter yang efisien dan dapat menghasilkan rasio konversi tegangan yang tinggi. Pada penelitian menggunakan firefly algorithm (FFA) dan modified perturb and observe (P&O) sebagai MPPT untuk mendapatkan nilai daya optimal pada keluaran PV. Konverter DC-DC yang digunakan adalah hybrid cuk converter boost mode yang memiliki rasio tegangan yang tinggi. Dari DC-link kemudian masuk ke inverter (VSI) yang diinterkoneksi dengan grid menggunakan current control. Hasil analisis simulasi menunjukan bahwa FFA dan P&O mampu menghasilkan daya PV yang optimum dengan riak yang kecil dan konverter hybrid cuk converter boost mode dapat menghasilkan rasio tegangan yang lebih besar dibandingkan konverter cuk biasa. Kata Kunci — PV, MPPT FFA, MPPT P&O, Hybrid Cuk Converter, DC-Link, Inverter Grid Connecte
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