22 research outputs found

    Metode Ekstraksi Pelarut Berbantuan Ultrasonik Untuk Recovery Minyak Dari Limbah Cair Pabrik Kelapa Sawit

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    In this study, application of ultrasound-assisted solvent extraction for recovery of oil from palm oil mill effluent (POME)was studied. Extraction conditions such as volume ratio of POME to solvent, extraction time and type of solvent were investigated. Extraction was carried out at room temperature with total volume (POME and solvent) of 300 ml. The experimental results showed that ultrasound-assisted extraction provided higher yield than without ultrasound using mechanical stirring. The highest oil yield of 0.265 % obtained at ultrasound-assisted extraction condition of volume ratio of POME to solvent 5:1, extraction time of 60 minutes using n-hexane as solvent. The highest oil yield and carotene concentration were obtained by n-hexane. Meanwhile, there was no significant differenece of carotene concentration obtained from ultrasound-assisted and without ultrasound-assisted extraction

    Dynamic cervical lung lobe herniation in a Shih Tzu dog

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    An 8-year-old spayed female Shih Tzu was referred to University Veterinary Hospital (UVH) with history of chronic coughing for more than a year duration. Dry, hacking cough was heard and bilateral wheezing lung sound was noted upon physical examination. Auscultation of heart revealed left apical systolic heart murmur Grade III/VI. A soft, intermittent swelling was observed at ventral neck, cranial to thoracic inlet (protruded upon expiration and collapsed upon inspiration). Thoracic radiography taken showed presence of apical radiolucency at cervical region and bronchial pattern at caudodorsal lungs with left atrium enlargement and right-sided heart enlargement. Echocardiographic examination revealed myxomatous mitral valve disease (MMVD) with mild regurgitation. Based on diagnostic imaging, this case was diagnosed as dynamic lung lobe herniation secondary to chronic coughing concurrent with myxomatous mitral valve disease. Other differential diagnosis that may lead to chronic cough such as of tracheal collapsed and bronchiectasis was not rule out

    Design of potassium ion conducting PVA based polymer electrolyte with improved ion transport properties for EDLC device application

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    This work presents a report on the preparation of plasticized polyvinyl alcohol PVA-based polymer electrolytes using solution cast technique and their characteristics using a number of electrochemical techniques. Electrical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and transfer number measurement (TNM) techniques were examined on the prepared films to determine the conductivity, decomposition voltage and ion transference number, respectively. The cyclic voltammetry (CV) and charge-discharging measurements were implemented on an assembled EDLC device to estimate the charge storage process and evaluate the device performance, respectively. The EIS was employed for measuring the direct current (DC) electrical conductivity of the films and calculating the ion transport parameters. The CV and charge-discharging responses were used to estimate the capacitance and stability, respectively. The influence of plasticization on the polymer electrolytes was investigated in terms of electrochemical properties. The TNM measurements were used to determine te and tion respectively. The obtained ionic transference number, tion for the electrolytes incorporated with 40 wt.% and 50 wt.% of glycerol content were found to be 0.969 and 0.944, respectively. The LSV study was used to identify the decomposition voltage of the sample. The absence of redox peaks was proved via CV technique, indicating the mechanism of the charge storing process that comprised ion accumulation at the interfacial region. The initial specific capacitance (Cs) of the fabricated EDLC displayed the value of 152.4 F/g

    The study of plasticized sodium ion conducting polymer blend electrolyte membranes based on chitosan/dextran biopolymers: Ion transport, structural, morphological and potential stability

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    The polymer electrolyte system of chitosan/dextran-NaTf with various glycerol concentrations is prepared in this study. The electrical impedance spectroscopy (EIS) study shows that the addition of glycerol increases the ionic conductivity of the electrolyte at room temperature. The highest conducting plasticized electrolyte shows the maximum DC ionic conductivity of 6.10 × 10−5 S/cm. Field emission scanning electron microscopy (FESEM) is used to investigate the effect of plasticizer on film morphology. The interaction between the electrolyte components is confirmed from the existence of the O–H, C–H, carboxamide, and amine groups. The XRD study is used to determine the degree of crystallinity. The transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D) of ions are determined using the percentage of free ions, due to the asymmetric vibration (υas(SO3)) and symmetric vibration (υs(SO3)) bands. The dielectric property and relaxation time are proved the non-Debye behavior of the electrolyte system. This behavior model is further verified by the existence of the incomplete semicircle arc from the Argand plot. Transference numbers of ion (tion) and electron (te) for the highest conducting plasticized electrolyte are identified to be 0.988 and 0.012, respectively, confirming that the ions are the dominant charge carriers. The tion value are used to further examine the contribution of ions in the values of the diffusion coefficient and mobility of ions. Linear sweep voltammetry (LSV) shows the potential window for the electrolyte is 2.55 V, indicating it to be a promising electrolyte for application in electrochemical energy storage devices

    Transesterifikasi Minyak Kemiri Sunan Menjadi Biodiesel Menggunakan Katalis Padat K2O/C

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    Preparasi katalis padat K2O/C telah berhasil disiapkan dengan mengimpregnasi K2CO3 pada permukaan karbon aktif sekam padi selama 6 jam. Campuran tersebut dikalsinasi pada suhu 300 oC selama 3 jam hingga terbentuk K2O/C. Tujuan penelitian ini adalah untuk menginvestigasi kinerja katalis K2O/C dalam proses transesterifikasi minyak biji kemiri sunan menjadi biodiesel. Karbon sekam padi (C) dipersiapkan dengan proses pirolisis sekam padi, dilanjutkan dengan proses aktivasi untuk mendapatkan karbon sebagai penyangga berpori. Katalis K2O/C dikarakterisasi dengan Scanning Electron Microscopy (SEM) dan Energy-Dispersive X-ray (EDX). Hasil analisa EDX menunjukkan bahwa komposisi katalis didominasi oleh karbon (C) dan kalium (K). Fasa aktif K2O terdistribusi pada permukaan karbon aktif secara merata. Katalis K2O/C yang dihasilkan digunakan dalam reaksi transesterifikasi minyak kemiri sunan menggunakan reaktor batch. Yield biodiesel tertinggi dicapai hingga 98,68% ketika menggunakan katalis 4%, loading K2CO3 pada karbon aktif 0,5% berat, waktu reaksi 90 menit, serta rasio molar metanol terhadap minyak 8:1. Katalis K2O/C sangat berpotensi untuk dikembangkan selanjutnya sebagai salah satu katalis padat untuk mengkonversi minyak nabati menjadi biodiesel

    Blending and characteristics of electrochemical double-layer capacitor device assembled from plasticized proton ion conducting chitosan:dextran:NH4PF6 polymer electrolytes

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    This research paper investigates the electrochemical performance of chitosan (CS): dextran (DX) polymer-blend electrolytes (PBEs), which have been developed successfully with the incorporation of ammonium hexafluorophosphate (NH4PF6). X-ray diffraction (XRD) analysis indicates that the plasticized electrolyte system with the highest value of direct current (DC) ionic conductivity is the most amorphous system. The glycerol addition increased the amorphous phase and improved the ionic dissociation, which contributed to the enhancement of the fabricated device’s performance. Transference number analysis (TNM) has shown that the charge transport process is mainly by ions rather than electrons, as tion = 0.957. The CS:DX:NH4PF6 system was found to decompose as the voltage goes beyond 1.5 V. Linear sweep voltammetry (LSV) revealed that the potential window for the most plasticized system is 1.5 V. The fabricated electrochemical double-layer capacitor (EDLC) was analyzed with cyclic voltammetry (CV) and charge-discharge analysis. The results from CV verify that the EDLC in this work holds the characteristics of a capacitor. The imperative parameters of the fabricated EDLC such as specific capacitance and internal resistance were found to be 102.9 F/g and 30 Ω, respectively. The energy stored and power delivered by the EDLC were 11.6 Wh/kg and 2741.2 W/kg, respectively

    Metal complex as a novel approach to enhance the amorphous phase and improve the EDLC performance of plasticized proton conducting chitosan-based polymer electrolyte

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    Abstract This work indicates that glycerolized chitosan-NH4F polymer electrolytes incorporated with zinc metal complexes are crucial for EDLC application. The ionic conductivity of the plasticized system was improved drastically from 9.52 × 10−4 S/cm to 1.71 × 10−3 S/cm with the addition of a zinc metal complex. The XRD results demonstrated that the amorphous phase was enhanced for the system containing the zinc metal complex. The transference number of ions (tion) and electrons (te) were measured for two of the highest conducting electrolyte systems. It confirmed that the ions were the dominant charge carriers in both systems as tion values for CSNHG4 and CSNHG5 electrolytes were 0.976 and 0.966, respectively. From the examination of LSV, zinc improved the electrolyte electrochemical stability to 2.25 V. The achieved specific capacitance from the CV plot reveals the role of the metal complex on storage properties. The charge–discharge profile was obtained for the system incorporated with the metal complex. The obtained specific capacitance ranged from 69.7 to 77.6 F/g. The energy and power densities became stable from 7.8 to 8.5 Wh/kg and 1041.7 to 248.2 W/kg, respectively, as the EDLC finalized the cycles
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