Solar energy: Potential and future prospects

Kabir, Ehsanul,Kumar, Pawan,Kumar, Sandeep,Adelodun, Adedeji A.,Kim, Ki-Hyun Elsevier 2018 RENEWABLE & SUSTAINABLE ENERGY REVIEWS Vol.82 No.1

<P><B>Abstract</B></P> <P>The development of novel solar power technologies is considered to be one of many key solutions toward fulfilling a worldwide increasing demand for energy. Rapid growth within the field of solar technologies is nonetheless facing various technical barriers, such as low solar cell efficiencies, low performing balance-of-systems (BOS), economic hindrances (e.g., high upfront costs and a lack of financing mechanisms), and institutional obstacles (e.g., inadequate infrastructure and a shortage of skilled manpower). The merits and demerits of solar energy technologies are both discussed in this article. A number of technical problems affecting renewable energy research are also highlighted, along with beneficial interactions between regulation policy frameworks and their future prospects. In order to help open novel routes with regard to solar energy research and practices, a future roadmap for the field of solar research is discussed.</P>

A Review of Some Representative Techniques for Controlling the Indoor Volatile Organic Compounds

Ehsanul Kabir,김기현 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.3

Poor indoor air quality is now worldwide concern due to its adverse impacts on our health and environment. Moreover, these impacts carry a significant burden to the economy. Various technical approaches (e.g.,biological, activated carbon fiber (ACF), photocatlytic oxidation (PCO), etc.) have gained popularity in controlling indoor volatile organic compounds (VOCs). This is because removing indoor VOC sources or increasing ventilation rates is often not feasible or economical. This review provides an overview of the various air purification technologies used widely to improve indoor air quality. Although most of these technologies are very useful to remove indoor VOCs,there is no single fully satisfactory method due to their diversity and presence at the low concentration. To achieve technical innovations and the development of specific testing protocols, one should possess a better knowledge on the mechanisms of substrate uptake at VOC concentrations.

Sorptive Removal of Odorous Carbonyl Gases by Water

Kabir, Ehsanul,Kim, Ki-Hyun TheScientificWorldJOURNAL 2010 The Scientific World Journal Vol.10 No.-

<P>In this study, the removal capacity of deionized water was investigated against five gaseous carbonyl compounds (i.e., acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and isovaleraldehyde) by means of the gas stripping method. To determine the trapping behavior of these odorants by water, gaseous working standards prepared at three different concentration levels (i.e., for acetaldehyde around 300, 500, and 1,000 ppb) were forced through pure water contained in an impinger at room temperature. The removal efficiency of the target compounds was inspected in terms of two major variables: (1) concentration levels of gaseous standard and (2) impinger water volume (20, 50, 100, and 150 mL). Although the extent of removal was affected fairly sensitively by changes in water volume, this was not the case for standard concentration level changes. Considering the efficiency of sorption media, gas stripping with aqueous solution can be employed as an effective tool for the removal of carbonyl odorants.</P>

A Review of Some Representative Techniques for Controlling the Indoor Volatile Organic Compounds

Kabir, Ehsanul,Kim, Ki-Hyun Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.3

Poor indoor air quality is now worldwide concern due to its adverse impacts on our health and environment. Moreover, these impacts carry a significant burden to the economy. Various technical approaches (e.g., biological, activated carbon fiber (ACF), photocatlytic oxidation (PCO), etc.) have gained popularity in controlling indoor volatile organic compounds (VOCs). This is because removing indoor VOC sources or increasing ventilation rates is often not feasible or economical. This review provides an overview of the various air purification technologies used widely to improve indoor air quality. Although most of these technologies are very useful to remove indoor VOCs, there is no single fully satisfactory method due to their diversity and presence at the low concentration. To achieve technical innovations and the development of specific testing protocols, one should possess a better knowledge on the mechanisms of substrate uptake at VOC concentrations.

Trace metal contents in barbeque (BBQ) charcoal products

Kabir, Ehsanul,Kim, Ki-Hyun,Yoon, H.O. Elsevier 2011 Journal of hazardous materials Vol.185 No.2

<P><B>Abstract</B></P><P>In this study, the concentrations of trace elements contained in solid barbeque (BBQ) charcoal products have been investigated. Eleven brands of charcoal products were analyzed, consisting of both Korean (3 types) and imported products (eight types from three countries) commonly available in the Korean market places. The concentrations of trace metals in solid charcoal varied widely across metal types and between samples with the overall range of 5μgkg<SUP>−1</SUP> (As) to 118mgkg<SUP>−1</SUP> (Zn). The patterns of metal distribution between different products appeared to be affected by the properties of raw materials and/or the processes involved in their production. Although concentrations of certain trace metals were significantly high in certain charcoal samples, their emission concentrations were below legislative guidelines (e.g., the permissible exposure limit (PEL) set by the Occupational Safety and Health Administration (OSHA)). In light of the potential harm of grilling activities, proper regulation should be considered to control the use of BBQ charcoal from a toxicological viewpoint to help reduce the potential health risks associated with its use.</P>

Carbonyl Emissions during Food Decay from Kimchi, Fish, and Salted Fish

Kabir, Ehsanul,Kim, Ki-Hyun Korean Society for Atmospheric Environment 2008 Asian Journal of Atmospheric Environment (AJAE) Vol.2 No.2

In this study, the emissions of carbonyl compounds as offensive odorants were measured using three food types (Kimchi, fresh fish, and salted fish) as a function of time. Odor samples for each food type, collected at 0, 1, 3, 7, and 14 days, were analyzed by high performance liquid chromatography (HPLC). Only three kinds of carbonyl compounds were quantified above their respective detection limits: formaldehyde, acetaldehyde, and acetone. The emission patterns of these compounds were distinguishable from each other. Formaldehyde tends to peak at the beginning and decrease through time with unique patterns. Conversely, acetaldehyde and acetone seem to increase gradually through time. The results showed that relative patterns of carbonyl emissions were more distinguishable by compound type rather than food type.

An evaluation of two calibration procedures using thermal desorption-gas chromatography in the analysis of odorous volatile compounds.

Kabir, Ehsanul,Kim, Ki-Hyun Preston Publications 2011 Journal of Chromatographic Science Vol.49 No.9

<P>In this study, the relative performance of gas chromatography (GC) was investigated with respect to the differences in two types of calibration approaches with a thermal desorption (TD) method: the fixed standard concentration approach (FSC: the comparison of different sample volumes for a given standard) was compared with the fixed standard volume approach (FSV: the comparison of different concentration standards at a fixed loading volume). Gaseous working standards of seven odorants, including methyl ethyl ketone (MEK), butyl acetate, methyl isobutyl ketone, isobutyl alcohol, toluene, xylene, and a reference component, benzene, were prepared at four concentration levels (10-100 ppb). They were then analyzed by controlling the TD-loading volumes at six levels (40-1200 mL). The results derived by these contrasting calibration approaches showed moderate changes in the GC sensitivity, either with an increasing concentration (i.e., FSC), or with an increasing sample loading volume (i.e., FSV). Despite an eccentric trend of MEK, the TD-based analysis was fairly predictable and can be recommended for the analysis of the selected odorants.</P>

Environmental impacts of nanomaterials

Kabir, Ehsanul,Kumar, Vanish,Kim, Ki-Hyun,Yip, Alex C.K.,Sohn, J.R. Elsevier 2018 Journal of environmental management Vol.225 No.-

<P><B>Abstract</B></P> <P>Nanotechnology is currently one of the highest priority research fields in many countries due to its immense potentiality and economic impact. Nanotechnology involves the research, development, production, and processing of structures and materials on a nanometer scale in various fields of science, technology, health care, industries, and agriculture. As such, it has contributed to the gradual restructuring of many associated technologies. However, due to the uncertainties and irregularities in shape, size, and chemical compositions, the presence of certain nanomaterials may exert adverse impacts on the environment as well as human health. Concerns have thus been raised about the destiny, transport, and transformation of nanoparticles released into the environment. A critical evaluation of the current states of knowledge regarding the exposure and effects of nanomaterials on the environment and human health is discussed in this review. Recognition on the potential advantages and unintended dangers of nanomaterials to the environment and human health is critically important to pursue their development in the future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanotechnology has drawn great interests of researchers due to its immense potentiality. </LI> <LI> Nanotechnology has contributed to the gradual restructuring of diverse technologies. </LI> <LI> The presence of nanomaterials (NMs) can exert adverse effects on the human health. </LI> <LI> In this work, the exposure and effects of NMs is evaluated from various respects. </LI> <LI> The proper evaluation of NMs is offered for their future development and use. </LI> </UL> </P>

음식물 악취에 대한 탈취제 효용성의 평가연구

홍원필,안지원,Ehsanul kabir,Janice susaya,김옥헌,김기현 한국냄새환경학회 2009 실내환경 및 냄새 학회지 Vol.8 No.3

In this study, deodorizing efficiency of three deodorant products (1) A = ClO₂ Gel + charcoal, (2) B=Charcoal Gel, and (3) C = Gel (for Kimchi)) was investigated. For these experiments, a total of 15 odorants (4 reduced sulfur compounds, 2 volatile organic compounds, 7 carbonyl compounds, and 2 nitrogenous compounds) were investigated for a short term period. For the comparative analysis, 2 food types with strong odor properties (Kimchi and Fish) were selected and investigated. The analytical results were compared with respect to the blank sample (without deodorants) after normalization. Hence, if normalized concentration values are lower than unity one can assume that sample has positive deodorizing efficiency. The results of deodorant experiments indicate that the effects of the most common deodorant products are not effective enough to remove offensive odorants. However, the selection of deodorant products appears to be important, as they have very specific deodorizing efficiencies for certain compounds.

Airborne bioaerosols and their impact on human health

Kim, Ki-Hyun,Kabir, Ehsanul,Jahan, Shamin Ara Elsevier 2018 JOURNAL OF ENVIRONMENTAL SCIENCES -BEIJING- Vol.67 No.-

<P>Bioaerosols consist of aerosols originated biologically such as metabolites, toxins, or fragments of microorganisms that are present ubiquitously in the environment. International interests in bioaerosols have increased rapidly to broaden the pool of knowledge on their identification, quantification, distribution, and health impacts (e.g., infectious and respiratory diseases, allergies, and cancer). However, risk assessment of bioaerosols based on conventional culture methods has been hampered further by several factors such as: (1) the complexity of microorganisms or derivatives to be investigated; (2) the purpose, techniques, and locations of sampling; and (3) the lack of valid quantitative criteria (e.g., exposure standards and dose/effect relationships). Although exposure to some microbes is considered to be beneficial for health, more research is needed to properly assess their potential health hazards including inter-individual susceptibility, interactions with non-biological agents, and many proven/unproven health effects (e.g., atopy and atopic diseases). (C) 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.</P>