Because of the quick growth of electrical instruments used in noxious gas detection, the importance of gas sensors has increased. X-ray diffraction (XRD) can be used to examine the crystal phase structure of sensing materials, which affects the properties of gas sensing. This contributes to the study of the effect of electrochemical synthesis of titanium dioxide (TiO2) materials with various crystal phase shapes, such as rutile TiO2 (R-TiO2NTs) and anatase TiO2 (A-TiO2NTs). In this work, we have studied the effect of voltage on preparing TiO2 nanotube arrays via the anodization technique for gas sensor applications. The results acquired from XRD, energy dispersion spectroscopy (EDX), and field emission scanning electron microscopy (FE-SEM) elucidate that TiO2 was created. In addition, systematically examining the gas detection properties was also done. The gas sensor was produced from TiO2 nanotubes, and the gas-detecting features were directed at nitrogen dioxide (NO2), which is a hazardous gas. The sensor formed from TiO2 nanotubes detects NO2 gas at various temperatures, from room temperature to 300 oC, and it has good sensitivity to this gas. The results exhibit that the gas sensor that was synthesized at 30 V has good sensitivity and a short response time at room temperature for NO2 gas sensing.
In this paper, a new procedure is introduced to estimate the solution for the three-point boundary value problem which is instituted on the use of Morgan-Voyce polynomial. In the beginning, Morgan-Voyce polynomial along with their important properties is introduced. Next, this polynomial with aid of the collocation method utilized to modify the differential equation with boundary conditions to the algebraic system. Finally, the examples approve the validity and accuracy of the proposed method.
In this study, we investigate about the estimation improvement for Autoregressive model of the third order, by using Levinson-Durbin Recurrence (LDR) and Weighted Least Squares Error ( WLSE ).By generating time series from AR(3) model when the error term for AR(3) is normally and Non normally distributed and when the error term has ARCH(q) model with order q=1,2.We used different samples sizes and the results are obtained by using simulation. In general, we concluded that the estimation improvement for Autoregressive model for both estimation methods (LDR&WLSE), would be by increasing sample size, for all distributions which are considered for the error term , except the lognormal distribution. Also we see that the estimation improve
... Show MoreThe finite element approach is used to solve a variety of difficulties, including well bore stability, fluid flow production and injection wells, mechanical issues and others. Geomechanics is a term that includes a number of important aspects in the petroleum industry, such as studying the changes that can be occur in oil reservoirs and geological structures, and providing a picture of oil well stability during drilling. The current review study concerned about the advancements in the application of the finite element method (FEM) in the geomechanical field over a course of century.
Firstly, the study presented the early advancements of this method by development the structural framework of stress, make numerical computer solution
... Show MoreSince its first description as a cytotoxic agent, Olea europaea leaves extract gained significant popularity against human breast cancer, ethyl acetate extract of Olea europaea leaves obtained by acid hydrolysis method was evaluated in vitro as cytotoxic agent against new human breast cancer (AMJ13) cell line, using the MTT assay. One main pentacyclic triterpenoid; oleanolic acid, was isolated from leaves of Olea europaea by well-known two different methods, but not used for this compound before, the acidic hydrolysis method and basic acidic method. The presence of oleanolic acid was proved in both methods with qualitative and quantitative d
... Show MoreExperimental study of heat transfer coefficients in air-liquid-solid fluidized beds were carried out by measuring the heat rate and the overall temperature differences across the heater at different operating conditions. The experiments were carried out in Q.V.F. glass column of 0.22 m inside diameter and 2.25 m height with an axially mounted cylindrical heater of 0.0367 m diameter and 0.5 m height. The fluidizing media were water as a continuous phase and air as a dispersed phase. Low density (Ploymethyl-methacrylate, 3.17 mm size) and high density (Glass beads, 2.31 mm size) particles were used as solid phase. The bed temperature profiles were measured axially and radially in the bed for different positions. Thermocouples were connecte
... Show MoreThe purpose of this study is to deal with dust and interstellar molecular and atomic gas owing to obtaining a proportion of cold gas to dust and to understand the characteristics of the molecular gas in extragalactic data selected from the Herschel SPIRE/ FTS archive. The physical properties of a sample of 65 extragalactic spectra characterized by the activity of star formation were discussed in this work. Statistical analyses, using STATISTICA program, were made for the content of cold gas (MHI, MH2), dust mass (Mdust), cold temperature of dust (Td) and luminosities in Far-infrared to CO line radiations, while coefficients of partial correlation within those characteristics were established. The results
... Show MoreMethylotrophs bacteria are ubiquitous, and they have the ability to consume single carbon (C1) which makes them biological conversion machines. It is the first study to find facultative methylotrophic bacteria in contaminated soils in Iraq. Conventional PCR was employed to amplify MxaF that encodes methanol dehydrogenase enzyme. DNA templates were extracted from bacteria isolated from five contaminated sites in Basra. The gene specific PCR detected Methylorubrum extorquens as the most dominant species in these environments. The ability of M. extorquens to degrade aliphatic hydrocarbons compound was tested at the laboratory. Within 7 days, gas chromatographic (GC) studies of remaining utilize
... Show MoreIn this work gold nanoparticles (AuNPs), were prepared. Chemical method (Seed-Growth) was used to prepare it, then doping AuNPs with porous silicon (PS), used silicon wafer p-type to produce (PS) the processes doping achieved by electrochemical etching, the solution etching consist of HF, ethanol and AuNPs suspension, the result UV-visible absorption for AuNPs suspension showed the single peak located at ~(530 – 521) nm that related to SPR, the single peak is confirmed that the NPs present in the suspension is spherical shape and non-aggregated. X-ray diffraction analysis indicated growth AuNPs with PS. compare the PS layer without AuNPs and with AuNPs doped for electrical properties and sensitivity properties we found AuNPs:PS is more
... Show MoreRecently, in the last years, the world interested with Ecosystem is increased, and
that is interrelation with global atmospherically, by the existence followed
continuous animate variables, that is immediately influence at ecosystem nature by
inspection systems process such as satellite imagery or aerial photographs, that can
determination the wetland regions which aid fulfillment balance globe ecosystem. In
this study a determination of wetland regions in IRAQ, was done for Anbar
province, because many of regions Saturated with water or sponge and aquatic of
plant, additionally, existence metrology factors that significant role were depended
to be as important factor to define the wetland regions as temperatures,
Four hundred and fifty urine samples were collected from patients suffering from urinary tract infection from the General Azadi hospital in Kurkuk province ,during the period of october 2007 till march 2008 . Results of bacteriological culture revealed that (168) out of (450) studied samples (37.3%) gave positive culture using blood agar and macConkey agar ; different species of bacterial isolates were detected using morphological and biochemical tests ,from these isolates the highest percentage of the isolates were from Escherichia coli when it was (100) isolates out of (190) isolate (52.63%) . one hundred isolates were distributed between (77) from females and (23) from
... Show More