18 research outputs found

    Effect of Autonomous Vehicles on Car Rental Services in Sri Lanka

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    This paper will introduce a special kind of logistics management problem which exists in the car rental industry. In order to get a high degree of customer satisfaction and optimize vehicle fleet utilization, logistics managers in the car rental business have predicted few technologies: namely Autonomous driving and on demanding rentals. These ideas that will be seen in action in the near future approximately 10 years from now on. Optimizing resource deployment and reducing the logistics cost are the targets of logistics management in enterprise. This sort of research is prospective and useful for future development of the car rental industry

    Development of Starch-Based Materials Using Current Modification Techniques and Their Applications: A Review

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    Starch is one of the most common biodegradable polymers found in nature, and it is widely utilized in the food and beverage, bioplastic industry, paper industry, textile, and biofuel industries. Starch has received significant attention due to its environmental benignity, easy fabrication, relative abundance, non-toxicity, and biodegradability. However, native starch cannot be directly used due to its poor thermo-mechanical properties and higher water absorptivity. Therefore, native starch needs to be modified before its use. Major starch modification techniques include genetic, enzymatic, physical, and chemical. Among those, chemical modification techniques are widely employed in industries. This review presents comprehensive coverage of chemical starch modification techniques and genetic, enzymatic, and physical methods developed over the past few years. In addition, the current applications of chemically modified starch in the fields of packaging, adhesives, pharmaceuticals, agriculture, superabsorbent and wastewater treatment have also been discussed

    Investigations of wave reflection and transmission through gabion structures

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    This paper presents results from investigations carried out on the hydraulic performance of gabion structures, with respect to wave energy reflection and transmission processes. The focus of the study was to investigate the wave reflection and transmission characteristics, which are important in designing coastal structures with respect to energy dissipation. The paper presents the results of three hydraulic model investigations on vertical gabion structures. The experiments were designed to obtain detailed information of transmission and reflection characteristics of the structures thereby providing a complete profile of wave energy dissipation along the structures. The experimental programmes were conducted using large physical models to minimize scale effects. The results are discussed in the context of economical design, improved hydraulic performance and long term stability

    Development of Li(Ni1/3Mn1/3Co1/3-x Na (x) )O-2 cathode materials by synthesizing with glycine nitrate combustion technique for Li-ion rechargeable batteries

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    Glycine nitrate combustion technique was investigated for synthesizing Li(Ni1/3Mn1/3Co1/3-x Na (x) )O-2, x = 0-0.11 based transition metal oxide cathode materials for the rechargeable Li-ion battery (LIB) under this study. X-ray diffraction and scanning electron microscopy analysis showed that the synthesized powder samples were well crystalline rather spherical secondary particles. These secondary particles were composed of softly agglomerated nano-scale primary particles. The room temperature electrical conductivity of these Na-doped materials was significantly higher than that of the base material (2.60 x 10(-7) S/cm). Among them, the x = 0.04 material reported the highest electrical conductivity of 1.02 x 10(-03) S cm(-1). The half-cell assembled with cathode fabricated from Li(Ni1/3Mn1/3Co1/3)O-2 base material showed an initial discharge capacity of 187 mA h(-1) g(-1) with 25 mA h(-1) g(-1) irreversible capacity loss and 88.47% columbic efficiency at C/5 rate with a cut-off voltage of 2.5-4.6 V at 25 A degrees C. The electrochemical behavior of the x = 0.04 cathode showed a comparable initial discharge capacity as of the base material but with improved capacity retention

    Synthesis of Li (Ni<sub>1/3</sub>Mn<sub>1/3</sub>Co<sub>1/3</sub>) O<sub>2</sub> by Glycine Nitrate combustion process

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    Glycine Nitrate Combustion (GNC) method was successfully employed for the synthesis of Li(Ni1/3Mn1/3Co1/3)O2 with powder characteristics appropriate for the cathode of rechargeable  Li-ion batteries (LIBs). The outcome of this study proposed an optimum value of 0.6 for the Glycine: Nitrate ratio to obtain phase pure, well crystalline and rather spherical shaped Li(Ni1/3Mn1/3Co1/3)O2 micron size secondary particles by the GNC process. These secondary particles were composed of softly agglomerated primary particles of 200 - 300 nm in size. This particle morphology is regarded as a highly favorable for the functioning as a cathode in LIB. The electrical conductivity of Li (Ni1/3Mn1/3Co1/3) O2, determined by the dc four-probe technique, revealed the semiconducting nature with conductivity of the order of 10-7 S cm-1, at  25 °C. Lithium ion half-cell constructed with this prepared cathode material showed initial discharge capacity of 187 mAhg-1 with irreversible capacity of 25 mAhg-1 at C/5 rate with a cut-off voltage of 2.5 - 4.6 V, at 25 °C. This performance can be attributed to the highly favorable particle morphology obtained by the successful use of GNC process for the powder synthesis

    Synthesis of Li(Ni1/3Mn1/3Co1/3-xBax)O-2 cathode materials for lithium-ion rechargeable battery by glycine-nitrate combustion process

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    This study was based on developing Li(Ni1/3Mn1/3Co1/3-xBax)O-2 (x=0.04, 0.08, 0.11, 0.22, and 0.33) materials by substituting expensive Co with Ba, for the use in the cathode of rechargeable lithium-ion batteries (LIBs). Glycine-nitrate combustion method, which is a low-cost combustion technique, was employed to synthesize spherical shaped micron size secondary particles formed by densely agglomerated primary particles. The phase analysis performed by the X-ray diffractometry revealed the formation of the required layered phase of R-3m structure with trace amounts of a secondary phase. Furthermore, these Ba-substituted novel materials showed considerably higher electrical conductivity than those of the Li(Ni1/3Co1/3Mn1/3)O-2 base material. In the cell performance studies, the Ba-substituted cathode materials synthesized in this study showed slightly lower initial discharge capacity of 162.4mAhg(-1) but with considerably improved cycle performance compared to those of the Li(Ni1/3Co1/3Mn1/3)O-2 base material (187.7mAhg(-1)). More importantly, the Li(Ni1/3Mn1/3Co1/3-xBax)O-2, x=0.04 material clearly showed its ability to eliminate and prevent structural transformation usually associated with excess Li extraction at potentials above 4.5V. Therefore, the Li(Ni1/3Mn1/3Co1/3-xBax)O-2, x=0.04 material can be proposed as a potential candidate for the high-voltage cathode application of LIB

    Carbon Dioxide Capture through Physical and Chemical Adsorption Using Porous Carbon Materials: A Review

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    Due to rapid industrialization and urban development across the globe, the emission of carbon dioxide (CO2) has been significantly increased, resulting in adverse effects on the climate and ecosystems. In this regard, carbon capture and storage (CCS) is considered to be a promising technology in reducing atmospheric CO2 concentration. Among the CO2 capture technologies, adsorption has grabbed significant attention owing to its advantageous characteristics discovered in recent years. Porous carbon-based materials have emerged as one of the most versatile CO2 adsorbents. Numerous research activities have been conducted by synthesizing carbon-based adsorbents using different precursors to investigate their performances towards CCS. Additionally, amine-functionalized carbon-based adsorbents have exhibited remarkable potential for selective capturing of CO2 in the presence of other gases and humidity conditions. The present review describes the CO2 emission sources, health, and environmental impacts of CO2 towards the human beings, options for CCS, and different CO2 separation technologies. Apart from the above, different synthesis routes of carbon-based adsorbents using various precursors have been elucidated. The CO2 adsorption selectivity, capacity, and reusability of the current and applied carbon materials have also been summarized. Furthermore, the critical factors controlling the adsorption performance (e.g., the effect of textural and functional properties) are comprehensively discussed. Finally, the current challenges and future research directions have also been summarized

    Dynamically recommending repositories for health data : a machine learning model

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    Recently, a wide range of digital health record repositories has emerged. These include Electronic Health record managed by the government, Electronic Medical Record (EMR) managed by healthcare providers, Personal Health Record (PHR) managed directly by the patient and new Blockchain-based systems mainly managed by technologies. Health record repositories differ from one another on the level of security, privacy, and quality of services (QoS) they provide. Health data stored in these repositories also varies from patient to patient in sensitivity, and significance depending on medical, personal preference, and other factors. Decisions regarding which digital record repository is most appropriate for the storage of each data item at every point in time are complex and nuanced. The challenges are exacerbated with health data continuously streamed from wearable sensors. In this paper, we propose a recommendation model for health data storage that can accommodate patient preferences and make storage decisions rapidly, in real-time, even with streamed data. The model maps health data to be stored in the repositories. The mapping between health data features and characteristics of each repository is learned using a machine learning-based classifier mediated through clinical rules. Evaluation results demonstrate the model's feasibility. © 2020 ACM.E

    Surface modification of natural vein graphite for the anode application in Li-ion rechargeable batteries

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    Natural vein graphite with high purity and crystallinity is seldom used as anode material in lithium-ion rechargeable batteries (LIB) due to impurities and inherent surface structure. This study focuses on improving the surface properties of purified natural vein graphite surface by employing mild chemical oxidation. Needle-platy graphite sample with initial average carbon percentage of 99.83% was improved to 99.98% after treatment with 5 vol.% HCl. Surface modification of purified graphite was done by chemical oxidation with (NH4)(2)S2O8 and HNO3. Fourier-transform infrared spectra of graphite after chemical indicating surface oxidation of graphite surface. X-ray diffraction and scanning electron microscopic studies show the improvement of graphite structure without modification of crystalline structure. Electrochemical performance of lithium-ion cell assembled with developed anode material shows noticeable improvement of the reversible capacity and coulombic efficiency in the first cycle and cycling behavior after surface modification
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