Performance Comparison of a Water-to-Water Heat Pump System with Low GWP Refrigerant

Waseem Raza,Tuul Otgonpurev,Boo Chul Kim,Youn Cheol Park 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12

A study on the Combined Driven Refrigeration Cycle using Ejector

Waseem Raza,Gwang Soo Ko,박윤철 대한설비공학회 2021 International Journal Of Air-Conditioning and Refr Vol.29 No.1

The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4 mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.

Multistep sequestration and storage of CO₂ to form valuable products using forsterite

Raza, Waseem,Raza, Nadeem,Agbe, Henry,Kumar, R.V.,Kim, Ki-Hyun,Yang, Jianhua Elsevier 2018 ENERGY Vol.155 No.-

<P><B>Abstract</B></P> <P>The potential use of mineralogical carbonation is greatly acknowledged not only in reducing CO<SUB>2</SUB> emissions through carbon capture and storage (CCS) but also in producing industrially viable products. The direct carbonation of stable silicate minerals by supercritical CO<SUB>2</SUB> is unrealistic due to the low conversion efficiencies. The natural abundance of silicate minerals (e.g., olivine) is theoretically sufficient to fix the entire quantity of man-made CO<SUB>2</SUB> emissions, while carbonation of sorbents obtained from the dissolution of silicate rocks could proceed in a multistep (or continuous) process. In this work, the optimum experimental conditions for a multistep procedure of sequestration of minerals and conversion of CO<SUB>2</SUB> into valuable products were investigated using synthetic forsterite. In this research, magnesium sulfate obtained from the dissolution of forsterite in aqueous H<SUB>2</SUB>SO<SUB>4</SUB> was successfully carbonated to produce valuable byproducts (e.g., silica and hydrates of magnesite) with an economical carbonation as a means of CO<SUB>2</SUB> mitigation. Hydromagnesite, while being commercially applied in various fields (e.g., fire retardation and catalysis), can be transformed to magnesite which is stable for millions of years.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The carbonation of synthetic forsterite can be achieved via multistep reaction pathways. </LI> <LI> Through such conversion, the complete set of valuable products can be produced. </LI> <LI> This approach can effectively mitigate CO<SUB>2</SUB> through the formation of valuable products. </LI> <LI> In this work, optimum reaction conditions for such conversion has been sought. </LI> </UL> </P>

Recent advancements in supercapacitor technology

Raza, Waseem,Ali, Faizan,Raza, Nadeem,Luo, Yiwei,Kim, Ki-Hyun,Yang, Jianhua,Kumar, Sandeep,Mehmood, Andleeb,Kwon, Eilhann E. Elsevier 2018 Nano energy Vol.52 No.-

<P><B>Abstract</B></P> <P>Supercapacitors (SCs) are attracting considerable research interest as high-performance energy storage devices that can contribute to the rapid growth of low-power electronics (e.g., wearable, portable electronic devices) and high-power military applications (e.g., guided missile techniques and highly sensitive naval warheads). The performance of SCs can be assessed in terms of the electrochemical properties determined through a combination between the electrode and the electrolyte materials. Likewise, the charge storage capacities of SCs can be affected significantly by selection of such materials (e.g., via surface redox mechanisms). Enormous efforts have thus been put to make them more competitive with existing options for energy storage such as rechargeable batteries. This article reviews recent advances in SC technology with respect to charge storage mechanisms, electrode materials, electrolytes (e.g., particularly paper/fiber-like 3D porous structures), and their practical applications. The challenges and opportunities associated with the commercialization of SCs are also discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There has been great demand for a reliable technical platform for electrochemical storage. </LI> <LI> SCs are highly attractive option due to their fast storage capability and enhanced cyclic stability. </LI> <LI> This review covers the charge storage mechanisms of SCs along with comparison of selected SCs. </LI> <LI> We also discuss the technical challenges for developing SCs with high enough energy density. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Removal of phenolic compounds from industrial waste water based on membrane-based technologies

Waseem Raza,이제찬,Nadeem Raza,Yiwei Luo,김기현,Jianhua Yang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

Phenol and its derivatives from various man-made activities pose threats to public health and aquaticecosystems. A number of technologies (e.g., adsorption, oxidation, and biological methods) have beenproposed and tested to remove phenolic compounds from waste water. Among these technologies,membrane separation is considered one of the most efficient tools for abating phenolic compounds fromwaste water because of low capital cost, easy scalability, and ecofriendly production with the lowestemission of noxious compounds. In this review, we aim to address the potent role of membranetechnology by evaluating its performance in separating various phenolic compounds from industrialeffluents.

Performance Evaluation of Battery Thermal Management System in Electric Vehicle Using Induction Heater (Part 1: Parallel System)

Waseem Raza,Gwang Soo Ko,박윤철 대한설비공학회 2020 International Journal Of Air-Conditioning and Refr Vol.28 No.1

The fast evolving Electric vehicles (EVs) have become popular due to their zero-emission, fuel economy and better technology. However, the performance and life of batteries are very sensitive to temperature, it is important to maintain the proper temperature range. The battery thermal management system (BTMS) plays an important role in the performance of EVs. In this context, this study is conducted to evaluate the thermal performance of a battery with a parallel system using an induction heater. The GT-Suite software is used for simulation and evaluation. Mixture of water and ethylene glycol 50:50 is used as a working fluid and controlled by pump and valves. The heating rate of battery was analyzed by changing the capacity of induction heater 2, 4 and 6 kW and the flow rate of fluid was 2, 3, 5, 7, 10 and 27 LPM. The simulation work predicts that the battery heating rate increases with the increase in fluid flow. The study concluded that the battery heating rate is maximum with a flow rate of 27 LPM which is the highest amount of LPM, indicating that the rise in flow rate causes the increase in heating rate of the system which is also affected by induction heater capacity.

Recent developments in analytical quantitation approaches for parabens in human-associated samples

Raza, Nadeem,Kim, Ki-Hyun,Abdullah, Muhammad,Raza, Waseem,Brown, Richard J.C. Elsevier 2018 Trends in analytical chemistry Vol.98 No.-

<P>Parabens are an important class of antimicrobial compounds used as preservatives. Although they are considered to be safe when used within specified concentration limits, concerns about their potential toxicity have been raised due to their presence in cancerous breast tissues and their association with estrogenic activity, various kinds of allergies, and the malfunctioning of reproductive organs. The small quantities of parabens in human samples and complex nature of biological matrices make it difficult to determine free and/or conjugated forms of parabens and their metabolites. Consequently, it is desirable to develop sophisticated approaches for their sample pretreatments and subsequent determination. This review presents recent developments in the extraction, pre-concentration, and instrumental detection methods needed for the accurate quantification of parabens in human samples. This review is thus expected to help readers assess the potential impacts of parabens on human health through proper description of their exposure routes to human. (C) 2017 Elsevier B.V. All rights reserved.</P>

Basic experiment of an air-conditioner using ejector

Enkhbadral Gantulga,Waseem Raza,Youn Cheol Park,Jung Hyun Kim,Gwang Soo Ko 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.-

Hematologic Toxicity in Patients Undergoing Radical Anti-cancer Therapy: A Cross-Sectional Analysis of Patients in an Oncology Ward in India

Roy, Soumyajit,Mallick, Supriya,Raza, Md. Waseem,Haresh, Kunhi Parambath,Gupta, Subhash,Sharma, Daya Nand,Julka, Pramod Kumar,Rath, Goura Kisore Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Burden of cancer is progressively increasing in developing countries like India which has also led to a steep rise in toxicity due to anti-cancer therapy. A cross-sectional analysis was here conducted for patients with different malignancies (except leukaemia) who while undergoing radical anti-cancer therapy were admitted to our oncology ward from January-July 2013. In a total of 280 patients, the total number of toxicity events was 473. Nine patients expired over this time period. Among the events, grade 2 anaemia the most common (n=189) while the most common grades of neutropenia and thrombocytopenia were grade 4 (n=114) and grade 2 (n=48), respectively. Among the tracable microbial etiologies, gram negative bacteria were the most commonly found pathogens. Treatment interruptions took place in 240 patients (median duration=8.8 days). Prolonged hospital admission, intensive care and artificial ventilation support was needed to be given in 48, 7 and 13 patients respectively. Advanced NSCLC, KPS <70, pancytopenia and artificial ventilation requirement were found to have a significant impact on death. Such studies show the prevailing practice from institutes of our country and may guide us formulating a guideline for managing such toxicities for this part of the world.

Basic Study of an Ejector Air-Conditioner

Youn Cheol Park,Gwang Soo Ko,Waseem Raza 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.4