Formation of titania-silica mixed oxides in solvent mixtures and their influences for the photocatalytic CO₂ conversion to hydrocarbon

( Abdul Razzaq ),김현우,인수일 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

TiO₂-SiO₂ mixed oxide photocatalyst materials responsive to simulated solar light illumination have been synthesized by sol-gel method in various polar and nonpolar organic solvent mixtures. The photocatalysts were characterized by numerous experimental techniques and investigated for the photocatalytic conversion of CO₂ to CH₄. The TiO₂-SiO₂ mixed oxide photocatalysts prepared in the presence of nonpolar aromatic solvents such as xylene, toluene or benzene along with ethanol show high surface area, huge mesoporosity and enormous pore volume compared to the materials conventionally synthesized in a mixture of ethanol and hexane. The TiO₂-SiO₂ mixed oxide photocatalyst prepared in benzene along with ethanol yield 21.0 ppm g-1 h-1 of methane production; however the material synthesized in hexane shows negligible amount of methane production under simulated solar light irradiation. These results indicate that aromatic nonpolar solvents can tune the textural properties of photocatalysts compared to non-polar aliphatic solvents.

Local Scour Depth Around Bridge Piers: Performance Evaluation of Dimensional Analysis-based Empirical Equations and AI Techniques

Abdul Razzaq Ghumman,Husnain Haider,Ibrahim Saleh Al Salamah,MD Shafiquzzaman,Abdullah Alodah,Mohammed Alresheedi,Rashid Farooq,Afzal Ahmed,Ghufran Ahmed Pasha 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.8

Artificial Intelligence (AI) techniques, such as Artificial Neural Networks (ANN) and Adaptive Neuro-Fuzzy Inference Systems (ANFIS), and dimensional analysis-based empirical equations (DAEEs), can estimate scour depth around bridge piers. AI’s accuracy depends on various architectures, while DAEEs’ performance depends on experimental data. This study evaluated the performance of AI and DAEEs for scour depth estimation using flow velocity, depth, size of bed sediment, critical approach velocity, and pier width. The data from a smooth rectangular (20 m × 1 m) flume and a high-precision particle image velocimetry to study the flow structurearound the pier - width: 1.5 − 91.5 cm evaluated DAEEs. Various ANNs (5, 10, and 15 neurons), double layer (DL) and triple layers (TL), and different ANFIS settings were trained, tested, and verified. The Generalized Reduced Gradient optimization identified the parameters of DAEEs, and Nash–Sutcliffe efficiency (NSE) and Mean Square Error (MSE) evaluated the performance of different models. The study revealed that DL ANN-3 with 10 neurons (NSE = 0.986) outperformed ANFIS, other ANN (ANN1, ANN2, ANN4 & ANN5) models, and empirical equations with NSE values between 0.76 and 0.983. The study found pier dimensions to be the most influential parameter for pier scour.

INVESTIGATION ON LOCATION & ALIGNMENT OF A HEAD REGULATOR OF A CANAL

GHUMMAN ABDUL RAZZAQ,AKBAR ALI 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Design-Oriented Testing and Modeling of Reinforced Concrete Pile Caps

Khattab Saleem Abdul-Razzaq,Mustafa Ahmed Farhood 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.8

A new perspective in the design of reinforced-concrete pile caps is proposed in this paper, where the conventional approach leading to a reinforcing mesh is replaced by modelling the cap as a strut-and-tie system, in agreement with the strut-and-tie model, STM proposed by several design codes, ACI 318 included. Twelve RC pile-cap specimens were designed and manufactured. In the first group of 4 specimens the caps rest on two piles (Group A, axis-to-axis distance 300 mm), while in the second and third groups the piles are three and four, respectively (Groups B and C, axis-to-axis distance 400 mm). In each group, the first and third specimens were designed according to the traditional sectional method (reference specimens, with constant depth and lateral shoulders), while the design of the second and fourth specimens was based on the strut-and-tie method (no lateral shoulders; no corners opposite to the piles). Needless to say, the nominal design load was the same within each group. The tests clearly show that cap design based on strut-and-tie systems brings in a sizable reduction in terms of reinforcement amount and cost, accompanied by a less pronounced but still sizable extra bearing capacity.

CuO-TiO₂ nanostructure for CO₂ conversion to methane

김혜림,( Abdul Razzaq ),인수일 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

One of the major problems concerning environmental pollution and global warming is a rapid escalation in the level of carbon dioxide in atmosphere. The atmospheric CO₂ level can be reduced by converting it into useful products via thermochemical and photochemical processes. Amongst these conversion processes, the photochemical conversion is a cost effective and preferred process for the photoreduction of CO₂ into useful liquid fuels like methanol, formaldehyde, and methane gas. Here, we synthesized CuO-TiO₂ nanostructure, a hybrid material photocatalyst and tested for CO₂ photoreduction. The synthesis process involves the formation CuS nanostructure using electrochemical anodization followed by embedment of titanium isopropoxide as Ti precursor. The oxidation of the nanosctuctre is performed at temperature of 400 °C oxidizing Cu and Ti to form CuO-TiO₂ nanostructures.

Photocatalytic conversion of CO₂ into hydrocarbon fuels with titania using newly installed experimental setup

김혜림,( Abdul Razzaq ),허효정,인수일 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Photoreduction of CO₂ upon the photocatalysts surfaces into hydrocarbon fuels is one of the breakthroughs in the field of phtocatalysis. At present various approaches are investigated with the aim of increasing the conversion efficiency. In this poster, an attempt was made to testify the newly installed experimental setup in our laboratory. The experimental setup employed in the investigation consists of a reactor for CO₂ photoreduction into useful products and gas chromatography unit for analyzing the products composition. The reactor for photoconversion of CO₂ plays a vital role in experimental setup. The reactor assembly composes of a stainless steel platform, a circular reactor with an inlet, and outlet valves. For photocatalyctic CO₂ reduction, the reactor was loaded with the standard titania, Degussa P25 and was illuminated using 300 W Xe lamp with 1 sun condition. The methane yield was found to be 90 ppmㆍg^-1ㆍh^-1.

Facile fabrication of a noble metal-free photocatalyst: TiO2 nanotube arrays covered with reduced graphene oxide

김혜림,( Abdul Razzaq ),인수일 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

We report a noble metal-free novel nanostructured photocatalytic material fabricated using a facile synthesis approach, comprising a one-dimensional array of TNT covered with a reduced graphene oxide-TiO2 nanoparticles (rGO-TiO2 NP) composite. The novel nanostructure exhibits significantly improved photocurrent density and photochemical activity via conversion of CO2 into methane under simulated solar light irradiation. The improved performance appears due to the combined effect of enhanced light absorption and effective charge separation promoted by the rGO.

Photocatalytic conversion of CO2 into hydrocarbon fuels with titania using newly installed experimental setup

김혜림,( Abdul Razzaq ),허효정,인수일 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

Optimally Sizing Small Hydropower Project Under Future Projected Flows

Irfan Yousuf,Abdul Razzaq Ghumman,Hashim Nisar Hashmi 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

The global climate change trend is resulting in change in precipitation and temperature. This change is impacting water resources and flow patterns in rivers and streams world-wide. Due to this, it is becoming difficult to optimally size small hydropower plants and predict their performance during operations. This paper has endeavored to investigate a solution to this problem. Chitral River in the Kabul Basin in Upper Indus Region, Pakistan was selected as study area. Observed climatic data of Chitral for period 1984-2013 was obtained from Pakistan Meteorological Department (PMD), observed flow data of Chitral River for period 1989-2013 was obtained from Water and Power Development Authority (SWH-WAPDA) and future predicted climatic data (including temperature and precipitation) was downscaled from MEPH5 Global Circulation Model (GCM) using LARS WG 5 for period up to 2099 under A1B, A2 and B1 Emission Scenario. HEC-HMS was used to determine future river flow trends for periods 2014-30, 2046-65 and 2080-99. The historic and future river flows were used to size small hydropower plant using RETScreen 4.1 model. Multiple Objective Decision Making Methodology (MODM) was used to decide upon the most optimum size of the hydropower plant. This paper has determined that there will be 16.83% reduction in river flows simulated for 2011-30, 25.03% for 2046-65 and 22.02% for 2080-99 as compared to historical flows during 1989-2013. Consequently there will be 0.36% impact on yearly power generation due to river flow changes simulated for 2014-30, 6.25% for 2046-65 and 4.08% for 2080-99. It is concluded that optimal sizing of the small hydropower plants and better performance under variable flows due to climate changes can be ensured by taking into account the future river flows predicted through hydrological models in addition to historical flows. The results concluded that 49.64 MW will be the most optimal size of the small hydropower plant that will produce maximum electricity under future projected flows at the study area.

Cu₂ZnSnS₄ (CZTS)-ZnO: A noble metal-free hybrid Z-scheme photocatalyst for enhanced solar-spectrum photocatalytic conversion of CO₂ to CH₄

Zubair, Muhammad,Razzaq, Abdul,Grimes, Craig A.,In, Su-Il Elsevier 2017 Journal of CO<SUB>2</SUB> utilization Vol.20 No.-

<P><B>Abstract</B></P> <P>Development of photocatalytic materials for achieving the aspects of cost-effectiveness, improved performance and high stability is a subject of enormous interest among the photocatalysis research society. With the aim of achieving above mentioned features, herein we report a noble metal free, solar-light active, efficient and highly stable hybrid Cu<SUB>2</SUB>ZnSnS<SUB>4</SUB> (CZTS)-ZnO photocatalyst, synthesized by a simple two-step process. The morphological, crystalline, band alignment, optical and electronic properties of the prepared samples are intensively investigated. Photocatalytic performance is evaluated by measuring, under the simulated solar light, the ability of the photocatalyst to convert CO<SUB>2</SUB> into hydrocarbon fuels, primarily CH<SUB>4</SUB>. Our optimum CZTS-ZnO photocatalyst sample exhibits a CH<SUB>4</SUB> yield of 138.90 ppmg<SUP>−1</SUP> h<SUP>−1</SUP>, a factor of≈31 times greater than the un-sensitized ZnO nanorods, and≈22 times greater than the CZTS nanoparticles; with excellent stability yielding similar CH<SUB>4</SUB> production up to five test-cycles. The enhanced performance of the hybrid, noble metal-free photocatalyst can be attributed to improved light absorption and efficient separation of the photogenerated charge due to the Z-scheme heterojunction interface.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of hybrid Z-scheme CZTS-ZnO photocatalysts active under simulated solar light. </LI> <LI> The photocatalyst is prepared using a simple, low-cost two-step process. </LI> <LI> Varied CZTS amount influences the optical properties of materials. </LI> <LI> Hybrid photocatalysts are investigated for photocatalytic CO<SUB>2</SUB> conversion. </LI> <LI> The CO<SUB>2</SUB> conversion is mainly influenced by optical and charge separation due to Z-scheme heterojunction formation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>