Biosorption of Heavy Metals from Aqueous Solutions Using Water Hyacinth as a Low Cost Biosorbent

In this study, biosorption of Cu(II) and Zn(II) ions from aqueous solutions by water hyacinth fiber was investigated as a function of initial solution concentration, initial biomass concentration and temperature. Solutions containing copper and zinc ions were prepared synthetically in single component and the time required for attaining adsorption equilibrium was studied. The optimum sorption conditions were studied for each metal separately. The adsorption equilibrium data were adequately characterized by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich equations. The equilibrium biosorption isotherms showed that water hyacinth possess high affinity and sorption capacity for Cu(II) and Zn(II) ions, with sorption capacities of 99.42 mg Cu2+ and 83.01 mg Zn2+ per 1 g biomass, respectively. All results showed that water hyacinth fiber is an alternative low cost biosorbent for removal of heavy metal ions from aqueous media. Keywords: biosorption, low cost biosorbent, wastewater treatment, heavy meta

Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC)

: The continuous production of ethyl ester was studied by using a steady-state fixed bed reactor (FBR). Transesterification of palm stearin (PS) and waste cooking palm oil (WCPO) with ethanol in the presence of calcium oxide impregnated palm shell activated carbon (CaO/PSAC) solid catalyst was investigated. This work was determined the optimum conditions for the production of ethyl ester from PS and WCPO in order to obtain fatty acid ethyl ester (FAEE) with the highest yield. The effects of reaction variables such as residence time, ethanol/oil molar ratio, reaction temperature, catalyst bed height and reusability of catalyst in a reactor system on the yield of biodiesel were considered. The optimum conditions were the residence time 2-3 h, ethanol/oil molar ratio 16-20, reaction temperature at 800C, and catalyst bed height 300 mm which yielded 89.46% and 83.32% of the PS and WCPO conversion, respectively. CaO/PSAC could be used repeatedly for 4 times without any activation treatment and no obvious activity loss was observed. It has potential for industrial application in the transesterification of triglyceride (TG). The fuel properties of biodiesel were determined

Prompt Learning With Knowledge Memorizing Prototypes For Generalized Few-Shot Intent Detection

Generalized Few-Shot Intent Detection (GFSID) is challenging and realistic because it needs to categorize both seen and novel intents simultaneously. Previous GFSID methods rely on the episodic learning paradigm, which makes it hard to extend to a generalized setup as they do not explicitly learn the classification of seen categories and the knowledge of seen intents. To address the dilemma, we propose to convert the GFSID task into the class incremental learning paradigm. Specifically, we propose a two-stage learning framework, which sequentially learns the knowledge of different intents in various periods via prompt learning. And then we exploit prototypes for categorizing both seen and novel intents. Furthermore, to achieve the transfer knowledge of intents in different stages, for different scenarios we design two knowledge preservation methods which close to realistic applications. Extensive experiments and detailed analyses on two widely used datasets show that our framework based on the class incremental learning paradigm achieves promising performance.Comment: Under Revie

Retrieval-Augmented Meta Learning for Low-Resource Text Classification

Meta learning have achieved promising performance in low-resource text classification which aims to identify target classes with knowledge transferred from source classes with sets of small tasks named episodes. However, due to the limited training data in the meta-learning scenario and the inherent properties of parameterized neural networks, poor generalization performance has become a pressing problem that needs to be addressed. To deal with this issue, we propose a meta-learning based method called Retrieval-Augmented Meta Learning(RAML). It not only uses parameterization for inference but also retrieves non-parametric knowledge from an external corpus to make inferences, which greatly alleviates the problem of poor generalization performance caused by the lack of diverse training data in meta-learning. This method differs from previous models that solely rely on parameters, as it explicitly emphasizes the importance of non-parametric knowledge, aiming to strike a balance between parameterized neural networks and non-parametric knowledge. The model is required to determine which knowledge to access and utilize during inference. Additionally, our multi-view passages fusion network module can effectively and efficiently integrate the retrieved information into low-resource classification task. The extensive experiments demonstrate that RAML significantly outperforms current SOTA low-resource text classification models.Comment: Under Revie

Development of Type A Quadrupole Magnet for Siam Photon Source II

A prototype of a type A quadrupole magnet has been designed and manufactured for the 3 GeV storage ring of Siam Photon Source II, the second synchrotron light source in Thailand. The required quadrupole gradient is 51 T/m with the magnet effective length being 162 mm. Magnet modeling and magnetic field calculation were performed using Radia and Opera-3D. The bore radius of the magnet is 16 mm. The magnet will be operated at the excitation of 5544 A-turns. A mechanical analysis of the magnet structure was performed in SOLIDWORKS and ANSYS, where the maximum deformation of 0.003 mm was found at the magnet poles, and the first-mode natural frequency was higher than 100 Hz. The magnet yoke is made of AISI 1006 low-carbon steel with a fabrication tolerance of ±0.020 mm. Magnet coils are water-cooled and made of high-purity copper. The temperature rise of the coils was below 3.0 °C at the maximum excitation of 6664 A-turns, which is 20% above the operating point. Magnetic field measurement was carried out using the Hall probe technique. The measured magnetic field and coil temperature of the prototype show good agreement with the calculations

Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC)

The continuous production of ethyl ester was studied by using a steady-state fixed bed reactor (FBR). Transesterification of palm stearin (PS) and waste cooking palm oil (WCPO) with ethanol in the presence of calcium oxide impregnated palm shell activated carbon (CaO/PSAC) solid catalyst was investigated. This work was determined the optimum conditions for the production of ethyl ester from PS and WCPO in order to obtain fatty acid ethyl ester (FAEE) with the highest yield. The effects of reaction variables such as residence time, ethanol/oil molar ratio, reaction temperature, catalyst bed height and reusability of catalyst in a reactor system on the yield of biodiesel were considered. The optimum conditions were the residence time 2-3 h, ethanol/oil molar ratio 16-20, reaction temperature at 800C, and catalyst bed height 300 mm which yielded 89.46% and 83.32% of the PS and WCPO conversion, respectively. CaO/PSAC could be used repeatedly for 4 times without any activation treatment and no obvious activity loss was observed. It has potential for industrial application in the transesterification of triglyceride (TG). The fuel properties of biodiesel were determine

การศึกษาการเพิ่มประสิทธิภาพการใชัพลังงานโดยใช้ตัวเก็บประจุยิ่งยวดด้วยการจำลองผลรถไฟฟ้าหนึ่งขบวนA Study of Increasing Efficiency of Energy Utilization by Using Supercapacitor with a Single-train Simulation

บทความนี้นำเสนอแนวทางการเพิ่มประสิทธิภาพเชิงพลังงานในระบบรถไฟฟ้าขนส่งมวลชน โดยการจัดการพลังงานคืนกลับจากการเบรกรถไฟฟ้าด้วยการติดตั้งตัวเก็บประจุยิ่งยวดบนขบวนรถไฟ เพื่อกักเก็บพลังงานที่ได้จากการเบรกจ่ายคืนพลังงานกลับแล้วนำไปใช้ในระบบขับเคลื่อนรถไฟอย่างเหมาะสม โดยศึกษาผลกระทบของขนาดพิกัดของตัวเก็บประจุยิ่งยวดที่ติดตั้งบนขบวนรถต่อการเปลี่ยนแปลงการใช้พลังงานของระบบ การทดสอบจะใช้ระบบรถไฟฟ้าขนส่งมวลชนกระแสตรง BTS Skytrain สายสีลม พิจารณาการเคลื่อนที่และสมรรถนะของรถไฟฟ้า 1 ขบวน ทั้งขาขึ้นและขาล่อง จากการทดสอบพบว่าการติดตั้งตัวเก็บประจุยิ่งยวดบนขบวนรถไฟฟ้าที่เหมาะสมจะทำให้ประสิทธิภาพการใช้ประโยชน์จากพลังงานที่ได้จากการเบรกจ่ายคืนพลังงานกลับสูงตามไปด้วย โดยตัวเก็บประจุยิ่งยวดขนาดไม่เกิน 15 kWh สามารถช่วยให้ประหยัดพลังงานรวมได้สูงสุดประมาณ 18 % สามารถใช้พลังงานคืนกลับได้มากกว่า 80 % และลดพลังงานสูญเสียในระบบจ่ายไฟได้สูงสุดประมาณ 44%This article presents a guideline to enhance the efficiency of energy usage in Mass Rapid Transit Systems by means of management of regenerative energy from brake systems of an electric train using onboard supercapacitor. The onboard supercapacitors are designed to store regenerative energy and to appropriately supply energy for traction systems. The effects of capacity of onboard energy storage to energy usage of train system are studied based on the BTS Skytrain-Silom line, an urban mass transit system currently operated in Bangkok. The cases studies are performed numerically by considering a single train running along the ordinary operating route in the directions of up-track and down-track. From the numerical results, suitable capacity of supercapacitor can considerably increase the efficiency of regenerative energy usage. For energy saving purpose, a 15 kWh supercapacitor can increase energy saving rate by approximately 18%, provide regenerative energy’s recovery rate up to 80% and reduce energy losses in transmission system by 44%