555 research outputs found

    Pre Treatment Air Gambut dengan Tanah Lempung Lahan Gambut dan Aplikasi Membran Ultrafiltrasi Sistem Aliran Cross Flow untuk Menyisihkan Zat Organik dan Kekeruhan

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    Usage of peatland clays as liquid coagulant in pre treatment process still have a problem, so needed a process using ultrafiltration membranes. The purpose of this study was to determine the removal efficiency of organics matter and turbidity in pre treatment process using liquid coagulant of peatland clays with variation coagulant doses and learn the flux and rejection of organics matter and turbidity in peat water in processing using cross flow system ultrafiltration membrane without and with pre treatment. This research was conducted by varying the dose of liquid coagulant by 40 ml, 50 ml and 60 ml to 1000 ml of peat water and variations ultrafiltration membrane operating pressure of 0.5 bar, 1 bar and 1.5 bar. The result showed the best coagulant dosage is 40 ml, the highest flux obtained at processing using ultrafiltration membranes with a pre treatment at a pressure of 1.5 bar and highest rejection of organic matter and turbidity obtained on processing using ultrafiltration membranes with a pre treatment at a pressure of 0.5 bar respectively amounted to 96.34% and 100%

    Biocharcoal dari Serbuk Gergaji Kayu Cempaka (Elmerrillia Ovalis Miq) Serta Daya Adsorpsinya pada Zink dan Tembaga

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    Cempaka wood is a typical wood in Sulawesi Island and Maluku archipelago. This wood can be used for wood industry particularly for the manufacture of furniture. However, not only furniture can be produced from the wood but also the sawdust as the waste. This research utilized the sawdust of cempaka wood as biocharcoal to adsorb zinc and copper ions included in liquid organic fertilizer complement based on variation of weight and concentration of biocharcoal. The method used in this study was the spectrophotometry spectroDirect with sawdust of cempaka wood as the adsorbent. The results showed the characteristic of water content of biocharcoal was 4.05% while ash content was 7.75%. The optimum weight of biocharcoal to adsorb zinc ions was 40 mg with the adsorption capacity of 19.97 mg/g while for copper ions was 60 mg with the adsorption capacity of 16.16 mg/g. The optimum concentration of zinc and copper ions than can be adsorbed was 60 ppm with the adsorption capacity of 11.80 mg/g for copper ion and 9.29 mg/g for zinc ion

    Pengaruh Ekstrak Seledri (Apium Graveolens L.) terhadap Kelarutan Kalsium dalam Batu Ginjal

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    Celery (apium graveolens L.) contains chemicals that can be used as traditional medicine for various treatments. The research objective is to determine the effect of celery (apium graveolens L.) extractsin dissolving calcium kidney stones and calcium to determine the relationship between the concentration of extract of celery (apium graveolens L.) with the solubility of calcium in the kidney stones. Determination of the solubility of calcium in an extract of celery is by flame fotometer. The concentration of the extract was varried into 1, 5, 10, 15 and 20%. It showed that a concentration of 1% can dissolve the calcium as much as 15.104%; concentration of 5% can dissolve the calcium as much as 18.708%; concentration of 10% can dissolve the calcium as much as 23.683%; concentration of 15% can dissolve the calcium as much as 28.869%; and to a concentration of 20% can dissolve the calcium as much as 35.048%. It can be concluded that celeries extract can dissolve calcium of kidney stones

    Pengaruh Tekanan Transmembran dan Konsentrasi Chemical Cleaning Agent (NaOH) Membran Ultrafiltrasi Aliran Cross Flow pada Pengolahan Limbah Cair Laundry

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    The rapid economic development and community activities increasingly crowded cause appearance laundry business that effect on the environment. Ultrafiltration membrane is one of wastewater treatment technologies, but membranes have limitations such as the occurrence of the phenomenon of concentration polarization and fouling. The research objective of this study the effect of variations in transmembrane pressure against the rejection percentage COD, TSS , and the effect of variations in transmembrane pressure, concentration of washing of the efficiency and effectiveness of washing the membrane. the concentration of the washing of the efficiency and effectiveness of washing the membrane. The process of ultrafiltration membranes and membrane chemical washing wastewater laundry do with variations in pressure of 1 bar , 2 bar , and 3 bar. Variation of chemical cleaning agent concentration of 1%, 1.5% and 2%, rinsing with distilled water for 30 minutes, filtering wastewater laundry for 120 minutes, and washing using chemical cleaning agent (NaOH) for 30 minutes. Results highest percentage of rejection for COD parameter 86.6% and 85.7% TSS parameters in transmembrane pressure of 3 bar. The highest washing efficiency of the value of Flux Recovery (FR) gained 81.9%, and the value of resistance of Removal (RR) gained 82.59% with a concentration of 2% in the transmembrane pressure of 3 bar. The highest leaching effectiveness obtained at 50.21% with a concentration of 2% and a transmembrane pressure of 3 bar

    Elucidating the magma plumbing system of Ol Doinyo Lengai (Natron Rift, Tanzania) using satellite geodesy and numerical modeling

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    Ol Doinyo Lengai, located in the southern Eastern Branch of the East African Rift had several eruptive episodes with ash falls and lava flows (VEI 3) that caused damage to the nearby communities between 2007 and 2010. The volcano is remote and access is difficult. Although this volcano has been studied for decades, its plumbing system is still poorly understood, in part, because of the lack of precise observations of surface deformation during periods of quiet and unrest. This study investigates the volcanic plumbing system of Ol Doinyo Lengai and its surroundings using data from the network of permanent Global Navigation Satellite System (GNSS) sites monitoring the volcano (the TZVOLCANO network) around the flanks of the volcano and Interferometric Synthetic Aperture Radar (InSAR) observations. We constrain surface motions using 6 GNSS sites distributed around Ol Doinyo Lengai, operating between 2016 and 2021, and InSAR data covering nearly the same time period. Because of the complex local tectonics, the interpretation of the deformation pattern is not straightforward. We first invert the GNSS deformation and InSAR observations independently to infer potential deformation sources. Then we perform a joint inversion of both GNSS and InSAR datasets to verify our findings. We compare the results from the joint inversion with the results from inverting each dataset independently. The GNSS, InSAR, and joint inversion results point to a deflating source, located east of Ol Doinyo Lengai and southwest of the dormant volcano Gelai at a depth of 3.49 ± 0.03 km (GNSS inversion), 5.2 ± 1.2 km (InSAR inversion) and 3.49 ± 0.06 km (joint inversion) relative to the summit (vent) and with a volume change ΔV of -0.04 ± 0.05 × 106 m3 (GNSS inversion), -0.39 ± 0.29 × 106 m3 (InSAR inversion), and -0.04 ± 0.01 × 106 m3 (joint inversion). Although this is non-unique modeling of geodetic datasets with small signals, the inversion results suggest that Ol Doinyo Lengai could be fed by an offset multi-reservoir system that includes a shallow magma reservoir (<5 km) east of Ol Doinyo Lengai, possibly connected to a deeper magma reservoir

    Textile diamond dipoles for body centric communications at 2.45GHZ and 5.8GHZ

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    This study proposes textile diamond dipoles for body centric communication that operate at 2.45GHz and 5.8GHz. The proposed antennas have been rigorously tested under wearable and body centric measurements. Both substrates and conducting parts of the diamond dipoles are entirely made of textiles; which is deemed fit for wearable communications. Experiments such as bending, wetness and SAR were performed to investigate the antennas' performance for body communication realization. Bending was found not to cause any significant performance disruption. On the other hand, since the proposed antenna is not made of water-proof material, the performance was distorted under wet condition. However, once the antenna was dried out, the original performance was achieved. SAR measurement was also conducted and significant SAR values were observed when placing the proposed diamond dipoles close to human body

    Flat-plate solar array project. Volume 4: High-efficiency solar cells

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    The High Efficiency Solar Cell Task was assigned the objective of understanding and developing high efficiency solar cell devices that would meet the cost and performance goals of the Flat Plate Solar Array (FSA) Project. The need for research dealing with high efficiency devices was considered important because of the role efficiency plays in reducing price per watt of generated energy. The R&D efforts conducted during the 1982 to 1986 period are summarized to provide understanding and control of energy conversion losses associated with crystalline silicon solar cells. New levels of conversion efficiency were demonstrated. Major contributions were made both to the understanding and reduction of bulk and surface losses in solar cells. For example, oxides, nitrides, and polysilicon were all shown to be potentially useful surface passivants. Improvements in measurement techniques were made and Auger coefficients and spectral absorption data were obtained for unique types of silicon sheets. New modelling software was developed including a program to optimize a device design based on input characteristics of a cell

    Detection of Equine Herpesvirus Infection : Conventional Versus Molecular Approaches

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    Equine herpesvirus (EHV) are the highly contagious pathogens that infect both domestic and wild equine populations causing a major impact on equine industry worldwide. The methods for diagnosis of EHV have shown a vast improvement in the last decade. Although some conventional techniques are still applicable in certain cases, most of the clinical testing now focusing on rapid diagnosis by using the nucleic acid amplification-based techniques as major advances for the detection of EHV. The diagnosis of EHV does not only depend on clinical situation alone, but the suitability of diagnostic test is also vital for equine clinicians to make a decision regarding the specific treatments and control measures to be taken. Therefore, crucial understanding of the strengths and limitations of each assay are needed in order to interpret the results. Realizing the issue, this review intends to outline the clinical application of conventional approaches and the progress of the new molecular approaches. Relative advantages and limitations of each method have also been discussed

    Sorption potential of oil palm shell for the removal of chlorinated phenol from aqueous solution: Kinetic investigation

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    In this study, activated carbons (ACs) from oil palm shell (OPS) were prepared using the two-stage self-generated atmosphere method, comprising of a semi carbonization stage and a chemical activation stage, which were fixed at 300 oC and 500 oC respectively. The prepared adsorbents were tested in the removal of 2,4-dichlorophenol (2,4-DCP) from aqueous solution. The samples were impregnated by varying the zinc chloride (ZnCl2 ) to precursor (OPS) ratio, after which, the final products, ACs, underwent several aspects of chemical and physical characterizations, i.e. percentage of yield, moisture content, ash content, pH, porosity, adsorption kinetics and isotherms (2,4-DCP) and surface chemistry of the adsorbent. The results indicated that the percentage of yield, moisture content and ash content had increased in proportional to the increase in ZnCl2 ratio. It was found that AC4, with the impregnation ration of 1:4 (OPS:ZnCl2 ) had the highest adsorption capacity of 26.40 mg/g. While the maximum Brunauer, Emmett and Teller (BET) surface area of AC4 was found to be around 1020 m 2 /g. Adsorption studies indicated an increased in adsorption capacity in proportional to the increase in adsorbate initial concentration and adsorbent dosage, whereas a higher pH decreased the adsorption capacity. The adsorption isotherm of all the prepared ACs fitted well to the Langmuir model, while the sorption kinetics followed the pseudo-second order, indicating that the adsorption was a single layer chemisorption process
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