Vibration effects on remote sensing satellite images

Haghshenas, Javad Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.5

Vibration is a source of performance degradation in all optical imaging systems. Performance of high resolution remote sensing payloads is often limited due to satellite platform vibrations. Effects of Linear and high frequency sinusoidal vibrations on the system MTF are known exactly in closed form but the low frequency vibration effects is a random process and must be considered statistically. Usually the vibration MTF budget is defined based on the mission requirements and the overall MTF limitations. For analyzing low frequency effects, designer must know all the systems specifications and parameters. With a good understanding of harmful vibration frequencies and amplitudes in the system preliminary design phase, their effects could be removed totally or partially. This procedure is cost effective and let the designer to eliminate just harmful vibrations and avoids over-designing. In this paper we have analyzed the effects of low-frequency platform vibrations on the payload's modulation transfer function. We have used a statistical analysis to find the probability of imaging with a MTF equal or greater than a pre-defined budget for different missions. The worst and average cases have been discussed and finally we have proposed "look-up figures". Using these look-up figures, designer can choose the electro-optical parameters in such a way that vibration effects be less than its pre-defined budget. Furthermore, using the results, we can propose a damping profile based on which vibration frequencies and amplitudes must be eliminated to stabilize the payload system.

Climate effect on tree-ring widths of Fagus orientalis in the Caspian forests, northern Iran

Malek Haghshenas,Mohammad Reza Marvi Mohadjer,Pedram Attarod,Kambiz Pourtahmasi,Jeff Feldhaus,Seyed Mohammad Moein Sadeghi 한국산림과학회 2016 Forest Science And Technology Vol.12 No.4

This study aims at understanding the impacts of climate factors on the annual growth variations of oriental beech (Fagus orientalis Lipsky) at the Kheyrud Forest Research Station located in the Caspian forests of northern Iran. To this end, 18 disc samples were randomly taken from altitudes of 1038 to 1152 m above sea level. Tree rings were measured using TSAP-win software and a LINTABII machine. Since false and missing rings are typical in beech trees, skeleton plots were created to enhance crossdating accuracy. Chronologies were observed for a total of 15 samples. Meteorological data for rainfall and air temperature were recorded at the Nowshahr Meteorological Station, located near the study sites. Results showed a significant correlation between mean annual air temperature and radial growth (R D 0.54). Within the growing season, August temperatures reveal a significant correlation with tree ring (R D 0.41) while the highest association was observed in the previous December (R D 0.44) and the least association was found in February (R D 0.31). Excluding March (R D 0.33), there appeared to be no significant correlation between precipitation accumulated during and prior to the growing season and tree ring. In addition to oriental beech, there are many other species important to this region that may be sensitive to increasing temperatures.

Three solutions for a second-order Sturm-Liouville equation with impulsive effects

Hadi Haghshenas,Ghasem A. Afrouzi 한국전산응용수학회 2020 Journal of applied mathematics & informatics Vol.38 No.5

In this article, a second-order Sturm-Liouville problem with impulsive effects and involving the one-dimensional p-Laplacian is considered. The existence of at least three weak solutions via variational methods and critical point theory is obtained.

Electrochemical Behavior of Nanostructured Fe-Pd Alloy During Electrodeposition on Different Substrates

Rezaei, Milad,Haghshenas, Davoud F.,Ghorbani, Mohammad,Dolati, Abolghasem The Korean Electrochemical Society 2018 Journal of electrochemical science and technology Vol.9 No.3

In this work, Fe-Pd alloy films have been electrodeposited on different substrates using an electrolyte containing $[Pd(NH_3)_4]^{2+}$ (0.02 M) and $[Fe-Citrate]^{2+}$ (0.2 M). The influences of substrate and overpotential on chemical composition, nucleation and growth kinetics as well as the electrodeposited films morphology have been investigated using energy dispersive X-ray spectroscopy (EDS), current-time transients, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) patterns. In all substrates - brass, copper and sputtered fluorine doped tin oxide on glass (FTO/glass) - Fe content of the electrodeposited alloys increases by increasing the overpotential. Also the cathodic current efficiency is low due to high rate of $H_2$ co-reduction. Regarding the chronoamperometry current-time transients, it has been demonstrated that the nucleation mechanism is instantaneous with a typical three dimensional (3D) diffusion-controlled growth in the case of brass and copper substrates; while for FTO, the growth mode changes to 3D progressive. At a constant overpotential, the calculated number of active nucleation sites for metallic substrates is much higher than that of FTO/glass; however by increasing the overpotential, the number of active nucleation sites increases. The SEM micrographs as well as the XRD patterns reveal the formation of Fe-Pd alloy thin films with nanostructure arrangement and ultra-fine grains.

Application of Response Surface Methodology to Evaluate Stone Matrix Asphalt Stripping Potential

A. Khodaii,H. F. Haghshenas,H. Kazemi Tehrani,M. Khedmati 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.1

Stone matrix asphalt mixes are widely used in Western Europe due to its high strength properties in pavements, this type of mix is subjected to continuous wetting and drying cycles due to its porous structure leading to a higher potential for stripping. Lime has long been recognized and used in industry to reduce the stripping potential of SMA. Aggregate grading has also been identified to have an impact on the moisture damage potential. Response surface methodology was employed in this paper to evaluate the effect of lime content and grading on stripping potential of Stone Matrix Asphalt (SMA) using Tensile Strength Ratio (TSR) index. The statistical significances of linear, quadratic and interactive terms of the lime percent and grading were examined and second order polynomial regression equation was successfully fitted to the experimental results. The lime content of 1% and the finest aggregates resulted in a TSR optimum value of 91.8%±0.8%. It was further concluded that increasing the mastic asphalt would decrease the stripping potential of SMA and both of the two parameters evaluated, had approximately the same main effect on the TSR response.

Determination of rock mass strength parameters for use in local‑scale seismic landslide hazard zonation, Roudbar quadrangle, Iran

M. E. Mirabedini,E. Haghshenas,N. Ganjian 대한공간정보학회 2022 Spatial Information Research Vol.30 No.5

The aim is to identify and assessment of the shear strength parameters (φ and c) of the geological formation in the Roudbar quadrangle at a regional scale, to be used in seismic landslide hazard or susceptibility zonation. In this study, the earthquake-induced landslide inventory map following Roudbar-Manjil Earthquake was prepared. The geotechnical data of these studies, as well as findings from local consultants and construction projects, were collected as well. The shear strength parameters of each formation were then assessed by employing the geotechnical strength index classification system introduced. We illustrate the use of Newmark’s sliding block and Gibson’s applicable definition to evaluate strength parameter data. Newmark’s displacement method and Jibson’s applicable definition were employed to validate strength parameter data for slope static stability analysis. Slope stability analysis was modeled in a GIS environment using a digital elevation map and the normalized difference moisture index. The normalized difference moisture index was used to assess moisture content derived from Landsat spectral bands 4 and 5. Finally, the pseudo-static back-analysis of one sample landslide was performed to validate the strength parameters. The study provides necessary data for rapidly creating a map of earthquake- triggered landslides.

Green synthesis and characterization of Ni /NiO magnetic nanoparticles in water

Faezeh Farzaneh,Sara Haghshenas Kashanie 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.6

Ni/NiO magnetic nanoparticles was prepared using Ni(CH3COO)2 4H2O as starting material, acetylacetonate (AcAc) as template and water as a green solvent under reflux condition, followed by the calcination at 400 o C. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR). The size distribution of individual particles were determined to be about 18-20 nm. The prepared magnetic nanoparticles was found to be a good adsorbent for Congo red from solution.

Laboratory geometric calibration simulation analysis of push-broom satellite imaging sensor

Reza Sh., Hafshejani,Javad, Haghshenas Techno-Press 2023 Advances in aircraft and spacecraft science Vol.10 No.1

Linear array imaging sensors are widely used in remote sensing satellites. The final products of an imaging sensor can only be used when they are geometrically, radiometrically, and spectrally calibrated. Therefore, at the first stages of sensor design, a detailed calibration procedure must be carefully planned based on the accuracy requirements. In this paper, focusing on inherent optical distortion, a step-by-step procedure for laboratory geometric calibration of a typical push-broom satellite imaging sensor is simulated. The basis of this work is the simulation of a laboratory procedure in which a linear imager mounted on a rotary table captures images of a pin-hole pattern at different angles. By these images and their corresponding pinhole approximation, the correction function is extracted and applied to the raw images to give the corrected ones. The simulation results illustrate that using this approach, the nonlinear effects of distortion can be minimized and therefore the accuracy of the geometric position of this method on the image screen can be improved to better than the order of sub-pixel. On the other hand, the analyses can be used to proper laboratory facility selection based on the imaging sensor specifications and the accuracy.

OPEN ACCESS : Impact of eight weeks endurance training on biochemical parameters and obesity-induced oxidative stress in high fat diet-fed rats

( Seyed Reza Emami ),( Mahvash Jafari ),( Rouhollah Haghshenas ),( Aliasghar Ravasi ) 한국운동영양학회 2016 Physical Activity and Nutrition (Phys Act Nutr) Vol.20 No.1

[Purpose] High-fat diets (HFD) feeding is an important risk factor for obesity that is accompanied with metabolic syndrome. Appropriate exercise is recommended for obesity prevention. The molecular mechanisms and cellular pathways activated in response to HFD and exercise are not well understood. The purpose of this study was to investigate the effect of 8 weeks endurance training on some plasma biochemical parameters and oxidative stress in HFD induced obese rats. [Methods] Twenty-eight male Wistar rats were randomly divided into 4 groups: the standard diet (SD) group, endurance training group with a standard diet (ESD), HFD group, and endurance training group with high-fat diet (EHFD). After 8 weeks, blood samples were taken by cardiac puncture and plasma were used for determination of biochemical parameters and oxidative stress biomarkers. [Results] HFD significantly increased malondialdehyde level and decreased the activities of superoxide dismutase, catalase, and glutathione S-transferase and the content of glutathione in the plasma. HFD also increased activities of aspartate transaminase, alanine transaminase, lactate dehydrogenase, as well as levels of total cholesterol, triglyceride and low-density-lipoprotein-cholesterol. However, endurance training showed protective effect on changes in these parameters. [Conclusion] These findings suggested that HFD alters the oxidant-antioxidant balance, as evidenced by reduction in the antioxidant enzymes activities and glutathione level and enhanced lipid peroxidation. Endurance training can be beneficial for the suppression of obesity-induced oxidative stress in HFD rats through modulating antioxidant defense system and reduces the risk of obesity-associated diseases.

Impact of RGD Peptide Tethering to IL24/mda-7 (Melanoma Differentiation Associated Gene-7) on Apoptosis Induction in Hepatocellular Carcinoma Cells

Bina, Samaneh,Shenavar, Fatemeh,Khodadad, Mahboobeh,Haghshenas, Mohammad Reza,Mortazavi, Mojtaba,Fattahi, Mohammad-Reza,Erfani, Nasrollah,Hosseini, Seyed Younes Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.14

Background: Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24), a unique tumor suppressor gene, has killing activity in a broad spectrum of cancer cells. Herein, plasmids producing mda-7 proteins fused to different RGD peptides (full RGD4C and shortened RGD, tRGD) were evaluated for apoptosis induction with a hepatocellular carcinoma cell line, Hep-G2. The study aim was to improve the apoptosis potency of mda-7 by tethering to RGD peptides. Materials and Methods: Three plasmids including mda-7, mda-7-RGD and mda-7-tRGD genes beside a control vector were transfected into Hep-G2 cells. After 72 hours incubation, cell viability was evaluated by MTT assay. In addition, the rate of apoptosis was analyzed by flow cytometry using PI/annexin staining. To detect early events in apoptosis, 18 hours after transfection, expression of the BAX gene was quantified by real time PCR. Modeling of proteins was also performed to extrapolate possible consequences of RGD modification on their structures and subsequent attachment to receptors. Results and Conclusions: In MTT assays, while all mda-7 forms showed measurable inhibition of proliferation, unmodified mda-7 protein exhibited most significant effect compared to control plasmid (P<0.001). Again, flow cytometry analysis showed a significant apoptosis induction by simple mda-7 gene but not for those RGD-fused mda-7 proteins. These findings were also supported by expression analysis of BAX gene (P<0.001). Protein modelling analysis revealed that tethering RGD at the end of IL-24/Mda7 disrupt attachment to cognate receptor, IL-20R1/IL-20R2. In conclusion, fusion of RGD4C and shortened RGD peptides to carboxyl terminal of mda7, not only reduce apoptosis property in vitro but also disrupt receptor attachment as demonstrated by protein modelling.