379 research outputs found

    Modeling electrodialysis and a photochemical process for their integration in saline wastewater treatment.

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    Oxidation processes can be used to treat industrial wastewater containing non-biodegradable organic compounds. However, the presence of dissolved salts may inhibit or retard the treatment process. In this study, wastewater desalination by electrodialysis (ED) associated with an advanced oxidation process (photo-Fenton) was applied to an aqueous NaCl solution containing phenol. The influence of process variables on the demineralization factor was investigated for ED in pilot scale and a correlation was obtained between the phenol, salt and water fluxes with the driving force. The oxidation process was investigated in a laboratory batch reactor and a model based on artificial neural networks was developed by fitting the experimental data describing the reaction rate as a function of the input variables. With the experimental parameters of both processes, a dynamic model was developed for ED and a continuous model, using a plug flow reactor approach, for the oxidation process. Finally, the hybrid model simulation could validate different scenarios of the integrated system and can be used for process optimization

    Traumatic 6th Nerve Palsy Managed with Medial Rectus Recession with Hangback Sutures and Hummelsheim Procedure

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    Traumatic paralytic esotropia due to 6th nerve palsy is not uncommon but difficult to manage. We reported a case of 38‑year‑old male who sustained head injury in road traffic accident 15 years ago and inward deviation of his left eye. His vision in right eye was 20/20 and counting fingers at one foot in the left eye. He had >70 prism diopters esotropia in the left eye with restriction of movements in all directions of gaze except adduction. His forced duction test was positive. Examinations of the anterior and posterior segments of both eyes were within normal limits. Magnetic resonance imaging suggested old traumatic insult in the left eye. Diagnosis of left eye traumatic 6th nerve palsy with medial rectus contracture was made. Left medial rectus recession with hangback sutures and Hummelsheim procedure were performed. Postoperatively, the patient’s vision in the left eye had improved to 20/80 the esotropia had reduced to 15 prism diopters (delta).Keywords: Abducent nerve, esotropia, traum

    Optimization of a hydrodynamic cavitation reactor using salicylic acid dosimetry

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    In the present work, optimization of a hydrodynamic cavitation reactor, for maximizing the extent of hydroxyl radical generation, has been investigated using salicylic acid as a dosimeter. The effect of differing operating parameters such as inlet pressure into the reactor, shape of the orifice, and concentration of salicylic acid employed was investigated where the extent of hydroxyl radical generation was quantified in terms of concentration of the hydroxylated products 2,5- and 2,3- dihydroxybenzoic acid. With an upstream pressure of <100 psi no hydroxyl radicals were produced but excellent results were obtained with a small circular nozzle at 4000 psi and a salicylate concentration of 750 ppm. The use of a combination of ultrasound along with hydrodynamic cavitation is also reported for the first time and results in a 15% improvement in the hydroxyl radical generation when the distance between the orifice and transducer is 5 mm to 10 mm

    Efficacy of Ayurvedic multidimentional therapy in Darunaka - A Case Study

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    Ancient Acharyas have stated that ‘Shira’ is one among the ‘Dashapranayatana’ and it is very much important to protect the ‘Shira’ from any external and internal trauma as all sensory organs or Indriyas are located here. Darunaka is a condition affecting the Shirotwaka and hair and it is commonly encountered in a clinical practice. It affects almost everyone mostly in the adult life. Dryness, itching, scaling of the scalp along with hair-fall are the cardinal symptoms of this disease involving mainly vitiated Vata and Kapha Doshas. In modern dermatological practice, there is no any satisfactory remedy for this irritating disorder. Hence, many patients are looking with a hope towards Ayurveda. In the present case study, a 22 years old female patient having symptoms of Darunaka was treated with Ayurvedic Chikitsa. The combine effect of Shodhana Chikitsa and Shamana Aushadhis along with Sthanika Chikitsa in the form of Lepa and Dhavana were advocated and at the same time, Nidana Parivarjana was strictly followed. The assessment of symptoms of the disease was done with the help of gradation index of symptoms of Darunaka. There was significant relief in all the complaints of patient within a period of two months

    Ultrasound intensification suppresses the need of methanol excess during the biodiesel production with Lipozyme TL-IM

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    The synthesis of biodiesel from sunflower oil and methanol based on transesterification using the immobilized lipase from Thermomyces lanuginosus (Lipozyme TL-IM) has been investigated under silent conditions and under an ultrasound field. Ultrasound assisted process led to reduced processing time and requirement of lower enzyme dosage. We found for the first time that ratio 1:3 (oil to methanol) was favoured for the ultrasound assisted enzymatic process which is lower as that favoured for the silent process (ratio of 1.4). Our results indicate that intensification provided by ultrasound suppresses the need of the excess of the methanol reactant during the enzymatic biodiesel production. Ultrasound assisted enzymatic biodiesel production is therefore a faster and a cleaner processes.The authors acknowledge Brenntag India Pvt. Ltd. for kindly providing gift sample of lipase enzyme Lipozyme TL IM to carry out the research work. All authors acknowledge the funding of Department of Science and Technology and Portuguese Science Foundation under the Indo-Portuguese collaborative program

    Ultrasound enhances lipase-catalyzed synthesis of poly (ethylene glutarate)

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    The present work explores the best conditions for the enzymatic synthesis of poly (ethylene glutarate) for the first time. The start-up materials are the liquids; diethyl glutarate and ethylene glycol diacetate, without the need of addition of extra solvent. The reactions are catalyzed by lipase B from Candida antarctica immobilized on glycidyl methacrylate-ter-divinylbenzene-ter-ethylene glycol dimethacrylate at 40 °C during 18 h in water bath with mechanical stirring or 1 h in ultrasonic bath followed by 6 h in vacuum in both the cases for evaporation of ethyl acetate. The application of ultrasound significantly intensified the polyesterification reaction with reduction of the processing time from 24 to 7 h. The same degree of polymerization was obtained for the same enzyme loading in less time of reaction when using the ultrasound treatment. The degree of polymerization for long-term polyesterification was improved approximately 8-fold due to the presence of sonication during the reaction. The highest degree of polymerization achieved was 31, with a monomer conversion of 96.77%. The ultrasound treatment demonstrated to be an effective green approach to intensify the polyesterification reaction with enhanced initial kinetics and high degree of polymerization.This study was supported by Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The work was also supported by Bioprocess and Bionanotechnology Research Group (BBRG) of Minho University and the Post Graduate Funding Program of Jiangnan University for Overseas Study. All authors also acknowledge the funding of Department of Science and Technology and Portuguese Science Foundation under the Indo-Portuguese collaborative program

    Build orientation optimization problem in additive manufacturing

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    Additive manufacturing (AM) is an emerging type of production technology to create three-dimensional objects layer-by-layer directly from a 3D CAD model. AM is being extensively used by engineers and designers. Build orientation is a critical issue in AM since it is associated with the object accuracy, the number of supports required and the processing time to produce the object. Finding the best build orientation in the AM will reduced significantly the building costs and will improve the object accuracy. This paper presents an optimization approach to solve the part build orientation problem considering the staircase effect, support area characteristics and the build time. Two global optimization methods, the Electromagnetism-like and the Stretched Simulated Annealing algorithms, are used to study the optimal orientation of four models. Preliminary experiments show that both optimization methods can effectively solve the build orientation problem in AM, finding several global solutions.This work has been supported and developed under the FIBR3D project - Hybrid processes based on additive manufacturing of composites with long or short fibers reinforced thermoplastic matrix (POCI-01-0145-FEDER-016414), supported by the Lisbon Regional Operational Programme 2020, under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was also supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

    Variation of cataract surgery costs in four different graded providers of China

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    <p>Abstract</p> <p>Background</p> <p>China has the largest population of cataract patients in the world. However, the cataract surgery rate per million remains low in China. We carried out a survey on costs of cataract surgery from four different graded providers in China and analyzed differences in cost among these clinics.</p> <p>Methods</p> <p>1,189 patients were recruited for the study in four eye clinics, located in two provinces, Guangdong province in southern China and Hubei province in central China. The average cost of each cataract surgery episode was calculated including cost of intraocular lens, cost of drugs and facility cost. We also collected information on reimbursement and disposable annual income of local residents.</p> <p>Results</p> <p>Mean total cost per cataract intervention of four different providers varied considerably, ranging from US1,293inUnionHospitaltoUS 1,293 in Union Hospital to US 536 in Jingshan County Hospital. In all providers, except for Jingshan County Hospital, the cost exceeded annual disposable income of local rural residents. As to the proportion of patients with reimbursement, the figure for Union Hospital was only 36%, while for other three clinics it was more than 60%. There was a significant difference between mean reimbursement ratios, with the highest ratio in Zhongshan Ophthalmic Center being 71%.</p> <p>Conclusions</p> <p>Significant differences in costs of cataract surgery were found among the 4 different graded providers. A part of the cost was borne by patients. Proportion of patients with reimbursement and mean reimbursement ratios were higher in economically developed regions than in economically developing regions. Much more financial support should be directed into the rural New Cooperative Medical Scheme to raise the reimbursement ratio in rural China.</p
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