Engineering Commons^™

Biogenic Synthesis, Photocatalytic, And Photoelectrochemical Performance Of Ag–Zno Nanocomposite, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The development of coupled photoactive materials (metal/semiconductor) has resulted in significant advancements in heterogeneous visible light photocatalysis. This work reports the novel biogenic synthesis of visible light active Ag–ZnO nanocomposite for photocatalysis and photoelectrode using an electrochemically active biofilm (EAB). The results showed that the EAB functioned as a biogenic reducing tool for the reduction of Ag+, thereby eliminating the need for conventional reducing agents. The as-prepared Ag–ZnO nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic experiments showed that the Ag–ZnO nanocomposite possessed excellent visible light photocatalytic activity …

A Microfluidic Paper-Based Electrochemical Biosensor Array For Multiplexed Detection Of Metabolic Biomarkers, Chen Zhao, Martin M. Thuo, Xinyu Liu

Martin M. Thuo

Paper-based microfluidic devices have emerged as simple yet powerful platforms for performing low-cost analytical tests. This paper reports a microfluidic paper-based electrochemical biosensor array for multiplexed detection of physiologically relevant metabolic biomarkers. Different from existing paper-based electrochemical devices, our device includes an array of eight electrochemical sensors and utilizes a handheld custom-made electrochemical reader (potentiostat) for signal readout. The biosensor array can detect several analytes in a sample solution and produce multiple measurements for each analyte from a single run. Using the device, we demonstrate simultaneous detection of glucose, lactate and uric acid in urine, with analytical performance comparable to …

An Experimental And Modeling Study Of Formaldehyde And 1,3,5-Trioxane Flame Chemistry, Jeffrey S. Santner, Francis M. Haas, Frederick L. Dryer, Yiguang Ju

Francis (Mac) Haas

Paramagnetic Ionic Liquids For Measurements Of Density Using Magnetic Levitation, David K. Bwambok, Martin M. Thuo, Manza B.J. Atkinson, Katherine A. Mirica, Nathan D. Shapiro, George M. Whitesides

Martin M. Thuo

Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous …

Oxygen Vacancy Induced Band Gap Narrowing Of Zno Nanostructure By Electrochemically Active Biofilm, Mohammad Mansoob Khan Dr, A. A. Ansari, S. Kalathil, A. Nisar, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Band gap narrowing is important and advantageous for potential visible light photocatalytic applications involving metal oxide nanostructures. This paper reports simple biogenic approach for the promotion of oxygen vacancies in pure zinc oxide (p-ZnO) nanostructures using an electrochemically active biofilm (EAB), which is different from traditional techniques for narrowing the band gap of nanomaterials. The novel protocol improved the visible photocatalytic activity of modified ZnO (m-ZnO) nanostructures through the promotion of oxygen vacancies, which resulted in band gap narrowing of the ZnO nanostructure (Eg = 3.05 eV) without dopants. X-ray diffraction, UV-visible diffuse reflectance spectroscopy, x-ray photoelectron spectroscopy, electron paramagnetic …

Production Of Bioelectricity, Bio-Hydrogen, High Value Chemicals And 3 Bioinspired Nanomaterials By Electrochemically Active Biofilms, S. Kalathil, Mohammad Mansoob Khan Dr, M. H. Cho, J. Lee

Dr. Mohammad Mansoob Khan

Microorganisms naturally form biofilms on solid surfaces for their mutual benefits including protection from environmental stresses caused by contaminants, nutritional depletion or imbalances. The biofilms are normally dangerous to human health due to their inherited robustness. On the other hand, a recent study suggested that electrochemically active biofilms (EABs) generated by electrically active microorganisms have properties that can be used to catalyze or control the electrochemical reactions in a range of fields, such as bioenergy production, bioremediation, chemical/biological synthesis, bio-corrosion mitigation and biosensor development. EABs have attracted considerable attraction in bioelectrochemical systems (BESs), such as microbial fuel cells and microbial …

Enhanced Optical, Visible Light Catalytic And Electrochemical Properties Of Au@Tio2 Nanocomposites, Mohammad Mansoob Khan Dr, Sajid A. Ansari

Dr. Mohammad Mansoob Khan

Au@TiO2 nanocomposites and pure TiO2 were successfully used to know the effect of Au on TiO2 and their comparative optical, visible light catalytic andelectrochemical activities were investigated. Optical parameters such as band gap energy (Eg = 2.4 eV), absorption coefficient (a), refractive index (n) and dielectric constants (s) have been determined using different methods. Visible light (590 nm) catalytic activity of Au@TiO2 nanocomposites was performed for reducing methyl orange (MO) under visible light irradiation. CV, EIS and DPV studies demonstrate that Au@TiO2 nanocomposites exhibit redox behavior, charged its surface by accumulating electrons, store and release the electrons.

Measurements Of Nh3 Linestrengths And Collisional Broadening Coefficients In N2, O2, Co2, And H2o Near 1103.46 Cm−1, Kyle Owen, Et-Touhami Es-Sebbar, Aamir Farooq

Dr. Et-touhami Es-sebbar

Laser-based ammonia gas sensors have useful applications in many fields including combustion, atmospheric monitoring, and medical diagnostics. Calibration-free trace gas sensors require the spectroscopic parameters including linestrengths and collisional broadening coefficients to be known. Ammonia's strong ν2 vibrational band between View the MathML source has the high absorption strength needed for sensing small concentrations. Within this band, the 1103.46 cm−1 feature is one of the strongest and has minimal interference from CO2 and H2O. However, the six rotational transitions that make up this feature have not been studied previously with absorption spectroscopy due to their small line spacing ranging from …

Travelling In Cuba, Fathi Habashi

Fathi Habashi

Contact with Cuban scientists was established in 1986 when two researchers from Centro de Investigaciones para Industria Minero Metalurgica in Havana visited Laval University to get acquainted with research activities in the area of extractive metallurgy. This was followed in early 1987 by two more researchers from the same centre. Invitations were then received in late 1987, 1989, and 2008 to visit the nickel refineries in Cuba and to hold seminars at the University of Havana. The present report outlines these activities.

Enhanced Performance Of A Microbial Fuel Cell Using Cnt/Mno2 Nanocomposites As A Bioanode Materials, S. Kalathil, A Hoa, J Shim, Mohammad Mansoob Khan Dr, J Lee, M H. Cho

Dr. Mohammad Mansoob Khan

The anode electrode material is a crucial factor for the overall performance of a microbial fuel cell (MFC). In this study, a plain carbon paper modified with the CNT/MnO 2 nanocomposite was used as the anode for the MFC and a mixed culture inoculum was used as the biocatalyst. The modified anode showed better electrochemical performance than that of plain carbon paper, and Brunauer Emmett Teller (BET) analysis showed the high surface area (94.6 m2/g) of the composite. The Mn4+ in the nanocomposite may enhance the electron transfer between the microorganisms and the anode material which facilitates electron conduction. Additionally, …

Effects Of N2o And O2 Addition To Nitrogen Townsend Dielectric Barrier Discharges At Atmospheric Pressure On The Absolute Ground-State Atomic Nitrogen Density, Et. Es-Sebbar, N. Gherardi, F. Massines

Dr. Et-touhami Es-sebbar

Absolute ground-state density of nitrogen atoms N (2p3 4S3/2) in non-equilibrium Townsend dielectric barrier discharges (TDBDs) at atmospheric pressure sustained in N2/N2O and N2/O2 gas mixtures has been measured using Two-photon absorption laser-induced fluorescence (TALIF) spectroscopy. The quantitative measurements have been obtained by TALIF calibration using krypton as a reference gas. We previously reported that the maximum of N (2p3 4S3/2) atom density is around 3 × 1014 cm−3 in pure nitrogen TDBD, and that this maximum depends strongly on the mean energy dissipated in the gas. In the two gas mixtures studied here, results show that the absolute N …

Inhibition Of Bacillus Cereus Growth By Bacteriocin Producing Bacillus Subtilis Isolated From Fermented Baobab Seeds (Maari) Is Substrate Dependent, Donatien Kaboré, Dennis S. Nielsen, Hagrétoui Sawadogo-Lingan, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jakobsen, Line Thorsen

Pr. Mamoudou H. DICKO, PhD

59 Articles, Fathi Habashi

Fathi Habashi

Metal ions play an essential role in the functioning of all biological systems. They interact with charged and polar groups of all biopolymers. The study of structural and functional properties of metal binding proteins is an important area of modern physical and chemical biology. Metal cations and metal binding proteins are involved in all crucial cellular activities. Many pathological conditions are correlated with abnormal metal metabolism. Encyclopedia of Metalloproteins is a key resource that provides basic, accessible, and comprehensible information about this expanding field.

Mechaniczny Rozdział Faz Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Challenges And Prospects Of Processes Utilising Carbonic Anhydrase For Co2 Separation, Patrycja Szeligiewicz, Wojciech M. Budzianowski

Wojciech Budzianowski

This article provides an analysis of processes for separation CO2 by using carbonic anhydrase enzyme with particular emphasis on reactive-membrane solutions. Three available processes are characterised. Main challenges and prospects are given. It is found that in view of numerous challenges practical applications of these processes will be difficult in near future. Further research is therefore needed for improving existing processes through finding methods for eliminating their main drawbacks such as short lifetime of carbonic anhydrase or low resistance of reactive membrane systems to impurities contained in flue gases from power plants.

Breaking The Theft-Chain-Cycle: Property Marking As A Defensive Tool, William J. Bailey, David J. Brooks

Bill Bailey

The theft of property and its associated impact effects many parts of society. For example, a considerable amount of resources are expended in trying to reduce property theft, as such crime engenders both a financial and emotional impact (Grabosky, 1995, p. 1) on those involved. Factors such as fear of crime, increased insurance premiums and victimization are all outcomes of property crime. Much of the past research has focused on the mitigation of such crimes, collectively termed as ‘crime prevention’. Crime prevention are “any actions designed to reduce the actual level of crime and/or the perceived crime” (S.P. Lab, 2010, …

My Relations With Russian Polymer Science, Otto Vogl, Frank T. Traceski, Friderikh Diachekovski

Otto Vogl

No abstract provided.

Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski

Wojciech Budzianowski

This article describes methods of the determination of kinetic parameters from the thermogravimetric data set of biomass samples. It presents the methodology of the research, description of the needed equipment, and the method of analysis of thermogravimetric data. It describes both methodology of obtaining quantitative data such as kinetic parameters as well as of obtaining qualitative data like the composition of biomass. The study is focused mainly on plant biomass because it is easy in harvesting and preparation. Methodology is shown on the sample containing corn stover which is subsequently pyrolysed. The investigated sample show the kinetic of first order …

Temperature-Dependent Absorption Cross-Section Measurements Of 1-Butene (1-C4h8) In Vuv And Ir, Et-Touhami Es-Sebbar, Yves Benilan, Aamir Farooq

Dr. Et-touhami Es-sebbar

Vacuum ultraviolet (VUV) and infrared (IR) absorption cross-section measurements of 1-butene (1-C4H8; CH2=CHCH2CH3; Butylene) are reported over the temperature range of 296–529 K. The VUV measurements are performed between 115 and 205 nm using synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25 μm (∼6500–400 cm−1). The measured room-temperature VUV and IR absorption cross-sections are compared with available literature data and are found to be in good agreement. The oscillator strength for the electronic transition (A1A′→X1A′) around 150–205 nm …

Surface Coated Eu(Oh)3 Nanorods: A Facile Synthesis, Characterization, Mr Relaxivities And In Vitro Cytotoxicity, Krishna Katte, Ja Young Park, Wenlong Xu, Badrul Alam Bony, Woo Cheol Heo, Tirusew Tegafaw, Cho Rong Kim, Md Wasi Ahmad, Seonguk Jin, Jong Su Baeck, Yongmin Chang, Tae Jeong Kim, Ji Eun Bae, Kwon Seok Chae, Ji Yun Jeong, Gang Ho Lee

Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)

No abstract provided.

Synthesis Of Gold Nanoparticles Using A Stainless Steel Mesh, Thi Hiep Han, Mohammad Mansoob Khan Dr, S Kalathil, J Lee, M H. Cho

Dr. Mohammad Mansoob Khan

A novel, rapid, one-pot, and facile approach was developed to synthesize positively charged gold nanoparticles [(+) AuNPs] by employing an aqueous solution of HAuCl4·3H2O as a precursor at 30 °C and a stainless-steel mesh as a reducing agent. The penetration of Cl− ions into the stainless-steel surface results in corrosion on the stainless-steel surface and excretion of electrons which are used for reduction of Au3+ → Au0. As a result, (+) AuNPs 5-20 nm in size, mostly monodispersed, were synthesized within 3 h. The as-synthesized AuNPs were charaterized by UV-vis, DLS, XRD, TEM, HR-TEM, EDX and SAED. The utilization of …

Positively Charged Gold Nanoparticles Synthesized By Electrochemically Active Biofilm – A Biogenic Approach, Mohammad Mansoob Khan Dr, S. Kalathil, J. Lee, Moo Hwan Cho

Dr. Mohammad Mansoob Khan

Positively charged gold nanoparticles [(+) AuNPs] of 5-20 nm were synthesized by using electrochemically active biofilm (EAB) formed on a stainless steel mesh, within 30 minutes, in aqueous solution containing HAuCl4 as a precursor and sodium acetate as an electron donor. Electrochemically active bacteria present on biofilm oxidize the sodium acetate by producing electrons. Simultaneously, stainless steel also provides electrons because of the Cl− ions penetration into the stainless steel. Combined effect of both the EAB and stainless steel mesh enhances the availability of electrons for the reduction of Au3+ in the solution, which makes this synthesis efficient and fast. …