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Performance Study of Water Harvesting Unit Working Under Iraqi Conditions
Ali J. Talib,Abdul Hadi N. Khalifa,Ahmed Q. Mohammed 대한설비공학회 2019 International Journal Of Air-Conditioning and Refr Vol.27 No.1
The scarcity of water facing the world is one of the biggest challenges of this century. This challenge requires research plans in the field of water desalination that is not suitable for human use or the harvesting of water from the air. In this work, the performance of the water harvesting unit from the ambient air is studied. For this purpose, a vapor compression system is designed and built, a 372W reciprocating compressor is selected depending on the use of a small family consisting of four persons. The components of the vapor compression system are designed depending on the compressor power. The unit evaporator is modified to condensate the water vapor associated with the air instead of cooling the air. The effect of volume flow rate of air across the evaporator is studied. The range of air volume flow rate is from 224 to 244m3/h, as well as the operation mode of the unit which either continues to condensate or freeze the water vapor on the evaporator is also studied. The result showed that the water harvesting unit can work at a relative humidity as low as about 20%. The maximum water production for the unit is 7.9 l/day with a power consumption of 1.76 kW-h/l at the volume flow rate of air is 230m3/h. When an evaporative cooler is turned on in the test chamber, the amount of water production increases to about 13.11 l/day with a power consumption of 1.068 kW-h/l, for the same volume flow rate of air mentioned above.
Fatigue Damage Assessment of Tensile Specimen Considering Opening Stress in Crack Propagation Stage
Anjaly J. Pillai,Mohammed Hashmat Ahmed,Sudip Talukdar 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.6
Most of the structures in service are subjected to cyclic loading of variable amplitude. The effect of load interaction is necessary to accurately predict the fatigue life of components in design phase. In the present paper, a fatigue damage methodology under complex loading history is proposed considering two stages of damage process and considering the effect of sequence of loading. This is further modified by considering opening stress in crack propagation stage. The proposed methodologies are compared with the linear damage rule by illustrating an example of dynamically induced stress in a slender bar under uniform axial time varying force. The effect of various influencing parameters on fatigue life of bar is also studied. The proposed methodologies are further validated using experimental fatigue test results. The comparison shows a good agreement between theoretical and experimental results. It is found that conventional Miner’s rule estimates higher damage index compared to the proposed methodology.
Ahammad, A.J. Saleh,Pal, Poly Rani,Shah, Syed Shaheen,Islam, Tamanna,Mahedi Hasan, Md.,Qasem, Mohammed Ameen Ahmed,Odhikari, Noyon,Sarker, Subrata,Kim, Dong Min,Abdul Aziz, Md. Elsevier 2019 Journal of Electroanalytical Chemistry Vol.832 No.-
<P><B>Abstract</B></P> <P>Aiming at constructing a new nonenzymatic electrochemical nitrite sensor, we have prepared a screen-printed fluorine-doped tin oxide (FTO) electrode with activated jute carbon paste (AJCP) (AJCP-SP-FTO) synthesized from jute (<I>Corchorus</I> genus) sticks by using ZnCl<SUB>2</SUB> as activating agent and subsequent carbonizing at 850°C. Surface morphology, textural properties, chemical composition and nature of pores of AJC were studied by FE-SEM, XRD, EDS, Raman spectroscopy and BET analysis. The surface area of the AJC was found to be 1452.4m<SUP>2</SUP>/g with an average pore diameter of 2.6nm obtained from a BJH pore-size distribution curve. Electron transfer capacity at the interface of the AJCP material screen-printed FTO was studied by cyclic voltammetry (CV) and EIS techniques. The AJCP-SP-FTO sensor was used for amperometric detection of nitrite. The limit of detection (LOD) for nitrite oxidation was found to be 437nM for the proposed sensor. The sensitivity of AJCP-SP-FTO toward nitrite was 863.71μAmM<SUP>−1</SUP> cm<SUP>−2</SUP>. From the analysis of electrochemical data, the effective surface area of the AJCP-SP-FTO was 0.12cm<SUP>2</SUP>. We proposed a mechanism for sensitive detection of nitrite based on analysis of experimental findings of spectroscopic and electroanalytical techniques. We further utilized the proposed sensor for analyzing nitrite in tap water. The AJCP-SP-FTO electrode showed good reproducibility and stability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Activated jute carbon (AJC) material was prepared by using ZnCl<SUB>2</SUB> as activating agent. </LI> <LI> Surface morphology, textural properties, chemical composition and nature of pores of AJC were studied. </LI> <LI> A novel AJC paste screen printed FTO electrode was constructed for nonenzymatic electrochemical determination of nitrite. </LI> <LI> The detection limit and sensitivity of nitrite were calculated to be 437 nM and 863.71 μA μM<SUP>-1</SUP> cm<SUP>-2</SUP>, respectively. </LI> <LI> A mechanism for detection of nitrite was proposed based on analysis of spectroscopic and electroanalytical techniques. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Ahammad, A. J. Saleh,Hasan, Md. Mahedi,Islam, Tamanna,Al-Shehri, Mohammod Oudah,Anju, Anjuman Nesa,Alam, Md. Kawsar,Kim, Jong-Pil,Qasem, Mohammed Ameen Ahmed,Aziz, Md. Abdul The Royal Society of Chemistry 2018 NEW JOURNAL OF CHEMISTRY Vol.42 No.6
<P>A highly selective and sensitive electrochemical method was developed for the detection of dopamine (DA), based on a gold nanoparticle (AuNP)-coated taro carbon (TC)-modified glassy carbon electrode (AuNP-TC/GCE). This novel AuNP-TC material was simply prepared by carrying out a pyrolysis of a composite material obtained by treatment of an acid-treated taro stem powder with HAuCl4. Transmission electron microscopy (TEM), Raman spectroscopy, field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were employed to characterize the AuNP-TC material. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to characterize the modified electrode. The modified GCE exhibited a well-defined current response only toward the electrochemical oxidation of DA in a mixture solution of ascorbic acid (AA), DA, and uric acid (UA). This designed electrochemical sensor showed a linear response in the concentration range of 0.5 μM to 250 μM DA and a sensing limit (S/N = 3) of 0.25 μM was found. The sensor was also able to successfully detect DA in a dopamine hydrochloride injection (DAI). Moreover, the sensor exhibited excellent stability and reproducibility.</P>
M.A. Hasnat,Jamil A. Safwan,M. Shariful Islam,Zidnia Rahman,Mohammad Razaul Karim,Talha J. Pirzada,Ahmed Jalal Samed,Mohammed M. Rahman 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1
Electrochemical decolorization of Methylene blue (MB) molecules was studied at Pt electrode inpresence of KNO3 and KCl as the supporting electrolytes under acidic condition. The KNO3 electrolytedisplayed MB decolorization effect, where MB molecules exhibited two redox peaks at 0.48 V and0.34 V, respectively, in cyclic voltammogram (CV). The features of redox couples indicated thedimerization ofMBmolecules. In this simple preparation technique, a less amount of sample loading wasrequired, and the method displayed high efficiency toward decolorization of MB dye. This reportindicates the possibility for improving the quality of wastewater discharged from textile and otherindustries.