Graduate University of Advanced Technology

About: Graduate University of Advanced Technology is a education organization based out in Kerman, Iran. It is known for research contribution in the topics: Carbon paste electrode & Electrochemical gas sensor. The organization has 890 authors who have published 2169 publications receiving 31027 citations.

A new voltammetric sensor for electrocatalytic determination of vitamin C in fruit juices and fresh vegetable juice using modified multi-wall carbon nanotubes paste electrode

Abstract: The electrocatalytic oxidation of ascorbic acid (AA) has been studied by p-aminophenol modified carbon nanotubes paste electrode (APMCNTPE). Cyclic voltammetry (CV) and chronoamperometry were used to investigate the suitability of AP as a mediator for the electrocatalytic oxidation of AA in aqueous solution. The oxidation of AA occurs at a potential about 320 mV less positive than with the unmodified carbon paste electrode at pH 7.0. The catalytic reaction rate constant, kh was calculated (2.257 × 103 M−1s−1) using chronoamperometry. The differential pulsevoltammetric (DPV) peak currents of the electrode increased linearly with the corresponding AA concentration in the range of 2.0 × 10−7 M – 1.2 × 10−4 M with a detection limit of 8.0 × 10−8 M. The influence of pH and potential interfering substances on the determination of AA were studied. Finally, the proposed method was also examined as a selective, simple and precise electrochemical sensor for the determination of AA in real samples such as fruit juices and fresh vegetable juice.

Ab initio study of Pd-decorated single-walled carbon nanotube with C-vacancy as CO sensor

Abstract: In this paper, the adsorption of CO onto Pd-decorated (5,5) single-walled carbon nanotube (Pd/SWCNT) and Pd-doped (5,5) single-walled carbon nanotube (Pd/SWCNT-V) has been investigated using ab initio studies. The larger binding energies and charges transfer show that the adsorption of CO onto Pd/SWCNT is more stable than that of CO onto Pd/SWCNT-V. The Pd/SWCNT can be utilized as good sensors for CO molecules due to strong binding energy and large electron charge transfer between the Pd/SWCNT and this molecule. Furthermore, the topological properties of the electron density distributions for intramolecular interactions have been analyzed in terms of the Bader theory of atoms in molecules. Finally, the natural population analysis method has been used to evaluate the Pd–C and Pd/CO interactions.

Recent Advances in Electrochemical Sensors and Biosensors for Detecting Bisphenol A.

Abstract: In recent years, several studies have focused on environmental pollutants. Bisphenol A (BPA) is one prominent industrial raw material, and its extensive utilization and release into the environment constitute an environmental hazard. BPA is considered as to be an endocrine disruptor which mimics hormones, and has a direct relationship to the development and growth of animal and human reproductive systems. Moreover, intensive exposure to the compound is related to prostate and breast cancer, infertility, obesity, and diabetes. Hence, accurate and reliable determination techniques are crucial for preventing human exposure to BPA. Experts in the field have published general electrochemical procedures for detecting BPA. The present timely review critically evaluates diverse chemically modified electrodes using various substances that have been reported in numerous studies in the recent decade for use in electrochemical sensors and biosensors to detect BPA. Additionally, the essential contributions of these substances for the design of electrochemical sensors are presented. It has been predicted that chemically modified electrode-based sensing systems will be possible options for the monitoring of detrimental pollutants.

Laboratory Study of the Effect of Degrees of Saturation on Lime Concrete Resistance Due to the Groundwater Level Increment

Abstract: Lime concrete and lime treatment are two attractive techniques for geotechnical engineers in the construction of rail tracks and pavement layers, in slope protection of earth dams, and as a support layer for shallow foundations. The present study investigates the influence of different degrees of saturation upon the unconfined compressive strength (qu) of lime concrete. At first, the characteristics of used materials were determined. Then, the optimum amounts of water and clay soil were determined based on flow table tests and uniaxial compression tests. Specimens with an optimum level of clay, sand, lime, and moisture were prepared. After processing durations of 14, 28, 45, and 60 days in laboratory condition, the specimens were exposed to saturation levels ranging from 0 to 100%. The uniaxial compressive strength tests were then carried out on all specimens. The diagram of strength reduction of lime concrete versus different depths and saturation degrees (Sr) were developed. The results showed that the moisture has a significant effect on decreasing the strength of lime concrete. The specimens that placed in 100% of saturated condition failed completely, and in 20% of saturated condition, the strength value of specimens decreased about 42%. Also, the optimum percentages of clay and water for application in lime concrete with 7% lime, respectively 23 and 24.04% were determined. Based on the results of SEM test it was observed that the specimen was characterized by a rather well-structured matrix since both the filling of a large proportion of the coarse-grain soil voids by clay and the pozzolanic activity of lime led to retain less pore water in the specimen, increasing the uniaxial compressive strength, and consequently resist against swelling and shrinkage of the clay soil.