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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Gas Processing Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Carbon Dioxide,Hydrogen sulfide,Nanofluid,Wetted Wall Column,Diethanolamine,Nanoporous Graphene
- چکیده:
- چکیده انگلیسی: In this study, it was shown that how CO2 and H2S were removed from a natural gas stream, using a nanofluid containing nanoporous graphene in Diehanolamine (DEA). Before running the experiments, the appropriate values were chosen for the nanosheet dosage and the liquid and gas flow rates in the absorption experiments, which were performed in a laboratory scale wetted wall column. In the experiments, the nanosheet concentration ranged from 0.005 to 0.5 wt %.The surfactants and ultrasonic treatment were used to prepare stable nanofluids. It was indicated that using nanoporous graphene in DEA significantly affects on CO2 and H2S absorption in comparison to DEA. The absolute zeta potential values of nanofluids were greater than +35 mV. The effect of different parameters including nanosheet concentration as well as the CO2 and H2S concentration, in the feed gas stream (two different samples) on simultaneous absorption of H2S and CO2 from CO2-H2S-CH4 gas mixture was studied. In the case of using sample #1, (i.e. Feed gas mixture composition: % H2S and 3% CO2 in balance of CH4), an improvement in CO2 absorption to 39% and H2S absorption to 9% was observed at 0.1 wt% of nanoporous graphene/DEA nanofluids.
- انتشار مقاله: 11-10-1394
- نویسندگان: Ali Mohebbi,Mahboobeh Taheri,Hassan Hashemipour,Ali Morad Rashidi
- مشاهده
- جایگاه : پژوهشی
- مجله: Transactions on Combinatorics
- نوع مقاله: Journal Article
- کلمات کلیدی: Zero forcing number,connected zero forcing number,propagation time
- چکیده:
- چکیده انگلیسی: The zero forcing number $Z(G)$ of a graph $G$ is the minimum cardinality of a set $S$ with colored (black) vertices which forces the set $V(G)$ to be colored (black) after some times. ``color change rule'': a white vertex is changed to a black vertex when it is the only white neighbor of a black vertex. In this case, we say that the black vertex forces the white vertex. We investigate here the concept of connected zero forcing set and connected zero forcing number. We discusses this subject for special graphs and some products of graphs. Also we introduce the connected propagation time. Graphs with extreme minimum connected propagation times and maximum propagation times $|G|-1$ and $|G|-2$ are characterized.
- انتشار مقاله: 05-11-1397
- نویسندگان: Maryam Khosravi,Saeedeh Rashidi,Alemeh Sheikhhosseini
- مشاهده
- جایگاه : پژوهشی
- مجله: Research Journal of Pharmacognosy
- نوع مقاله: Journal Article
- کلمات کلیدی: Streptozotocin,Aqueous extract,Antidiabetic activity,nephroprotective activity,Urtica dioica L
- چکیده:
- چکیده انگلیسی: Background and objectives:Diabetes is the most common metabolic disorder with severe effects on quality of life. Decreasing serum glucose levels and normalization of kidney parameters is of great clinical importance for treating diabetes. Urtica dioica L. has been used in as anti-inflammatory, antioxidant, anti-fungal, and antibacterial agent. To our knowledge, there are little evidences about the anti-diabetic and nephroprotective actions of U. dioica L. The present study was carried out to assess the anti-diabetic and nephroprotective activities of U. dioica aqueous extract (UDAE) in streptozotocin (STZ) induced diabetic mice for 20 days. Methods: Male mice were divided into six groups: normal control, untreated diabetic, diabetic mice receiving 30, 90 and 270 mg/kg of plant extract (groups UDAE30, UDAE90 and UDAE270, respectively) or 30 mg/kg glibenclamide. At 20th day, the mice killed, dissected, then blood and kidney samples were collected for biochemical and histological parameters analysis. Results: Biochemically, UDAE at all doses and glibenclamide could significantly (p≤0.05) reduce the raised levels of blood glucose, urea and creatinine when compared to the untreated group. Histologically, differentdoses of UDAE (especially UDAE270) and glibenclamide could significantly (p≤0.05) decrease the volume and length of the renal structures as compared to the untreated group. Conclusion: These results indicated thatUDAE could improve diabetic related metabolic derangement such as hyperglycemia and elevated kidney markers.
- انتشار مقاله: 10-12-1397
- نویسندگان: Mohammad Mahdi Zangeneh,Ghobad Mohammadi,Saman Salmani,Payam Razeghi Tehrani,Khodabakhsh Rashidi,Akram Zangeneh*
- مشاهده
- جایگاه : پژوهشی
- مجله: Research Journal of Pharmacognosy
- نوع مقاله: Journal Article
- کلمات کلیدی: diabetes,Aqueous extract,Nephropathy,alloxan monohydrate,Gundelia tournefortii
- چکیده:
- چکیده انگلیسی: Background and objectives: Due to the rapid growth of global interest in use of ethno medicinal plants, their effects and safety assessment have become substantial. Gundelia tournefortii has been used as antioxidant, anti-inflammatory, antipyretic, anti-fungal, and antibacterial agent. In the present study, nephrprotective and antidiabetic properties of Gundelia tournefortii aqueous extract (GTAE) on diabetic mice has been assessed. Methods: Seventy mice were used and diabetes was induced by administration of 150 mg/kg of alloxan monohydrate intraperitoneally in 60 mature male mice and they were randomly divided into 6 groups. Also one group (10 mice) was considered as the negative control group which received normal saline. The treatment groups received glibenclamide 10 mg/kg (G10) and 5, 10, 20 and 40 mg/kg of GTAE through gavage for 20 days. Also, one group was considered as the non-diabetic control. On the last day, levels of blood glucose, urea and creatinine were measured in serum. After tissue processing, 5 μm sections of the kidneys were prepared and were stained by hematoxylin and eosin and used for stereological analysis. Results: GTAE at all doses and G10 significantly (p≤0.05) reduced the raised levels of blood glucose, creatinine and urea as compared to the untreated diabetic mice. Multipledoses of GTAE and G10 significantly (p≤0.05) decreased the volume and length of renal structures, compared to the diabetic untreated group. Conclusion: According to the obtained results, GTAE groups can regulate the levels of biochemical parameters and inhibit kidney damages in alloxan induced diabetic mice. It appears that GTAE can be suggested for treatment of diabetes as an anti-diabetic supplement or drug.
- انتشار مقاله: 26-09-1396
- نویسندگان: Ghobad Mohammadi,Mohammad Mahdi Zangeneh*,Khodabakhsh Rashidi,Akram Zangeneh
- مشاهده
- جایگاه : پژوهشی
- مجله: Physical Chemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Nano-adsorbent,PAMAM dendrimer,SBA-15-PAMAM,Acid dyes
- چکیده:
- چکیده انگلیسی: In this study, SBA-15-PAMAM mesoporous Nano-adsorbent was synthesized, characterized and applied for adsorption of Acid dyes (Acid Blue 62 (AB62) and Acid Red 266 (AR266)) from aqueous Medias. Adsorption of AB62 and AR266 on SBA-15 ordered mesoporous silica, polyamidoamine functionalized SBA-15(SBA-15-PAMAM), has been investigated. In order to assess the synthesized adsorbent constructional, FT-IR (Fourier transform infrared spectroscopy), TEM transmission electron microscopy images and XRD (X-ray diffraction) methods were utilized. In order to investigate and compare the adsorption of two acid dyes with each other, the chemical structure and molecular mass of two acid dyes on the synthesized Nano-adsorbent is compared with each other. The Acid Blue 62 dye with the structure of Anthrachinon (MW =422.43) and the Acid Red 266 dye with the structure of Azo (MW =467.78) is compared with each other. To appraise the proficiency of this Nano-adsorbent foradsrption of two acidic dyes from aqueous Medias, the efficacy of significant parameters comprising pH(2-10), adsorbent dosage(0.01-0.1g), dye concentration(200-600mg/g), contact time(10-120 min) and temperature(25-45°C) was investigated. The Langmuir, Freundlich, Tempkin and Dubin Radushkevich isotherms were perused. The empirical data were best demonstrated by the langmuir isotherm model with utmost adsorption valence of (1428.57 mg/g) for dye AB62 and (1111.11 mg/g) for dye AR266 at pH 2 and 25 °C and it is consented absolutely with the empirical data (R2 > 0.9933) for dye AB62 and (R2 > 0.9914) for dye AR266. It was concluded that SBA-15-PAMAM adsorbent could be applied as a significant adsorbent for acidic dyes removal.
- انتشار مقاله: 30-11-1396
- نویسندگان: Maryam Mirzaie,Abosaeed Rashidi,Habib-Allah Tayebi,Mohammad Esmail Yazdanshenas
- مشاهده
- جایگاه : پژوهشی
- مجله: Sahand Communications in Mathematical Analysis
- نوع مقاله: Journal Article
- کلمات کلیدی: frame,Hilbert $C^*$-module,G-Frame,Super Hilbert
- چکیده:
- چکیده انگلیسی: In this paper, we define super Hilbert module and investigate frames in this space. Super Hilbert modules are generalization of super Hilbert spaces in Hilbert C*-module setting. Also, we define frames in a super Hilbert module and characterize them by using of the concept of g-frames in a Hilbert C*-module. Finally, disjoint frames in Hilbert C*-modules are introduced and investigated.
- انتشار مقاله: 26-07-1395
- نویسندگان: Mehdi Rashidi-Kouchi,Mehdi Rashidi-Kouchi,Mehdi Rashidi-Kouchi
- مشاهده
- جایگاه : پژوهشی
- مجله: Sahand Communications in Mathematical Analysis
- نوع مقاله: Journal Article
- کلمات کلیدی: frame,G-Frame,Hilbert C*-module,g-frame operator,Bounded operator
- چکیده:
- چکیده انگلیسی: In this paper we proved that every g-Riesz basis for Hilbert space $H$ with respect to $K$ by adding a condition is a Riesz basis for Hilbert $B(K)$-module $B(H,K)$. This is an extension of [A. Askarizadeh, M. A. Dehghan, {em G-frames as special frames}, Turk. J. Math., 35, (2011) 1-11]. Also, we derived similar results for g-orthonormal and orthogonal bases. Some relationships between dual frame, dual g-frame and exact frame and exact g-frame are presented too.
- انتشار مقاله: 18-03-1393
- نویسندگان: Mehdi Rashidi-Kouchi,Akbar Nazari
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Nanoanalysis
- نوع مقاله: Journal Article
- کلمات کلیدی: nanocatalyst,Graphene,MCM-41,CVD method
- چکیده:
- چکیده انگلیسی: Graphene films were fabricated over synthesized MCM-41 nanocatalyst by chemical vapor
deposition method, and the reaction was carried in atmospheric pressure at 750˚C. Acetylene
gas used as a carbon precursor and the synthesis reaction took place in hydrogen atmosphere.
Mesoporous MCM-41 was synthesized at room temperature, using wet chemical method. The
synthesized metal free catalyst was characterized by XRD and N2 adsorption isotherms. The
catalytically synthesized graphene layers were characterized by Raman spectroscopy, scanning
electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated
that the favorable effect of MCM-41 with high BET surface area (908.76 m2/g) as an active
metal free nanocatalyst for fabricating graphene layers with high level of purity and homogeneity.
Because of simplicity, easy purification, and high yield of graphene synthesis offered by
this method, it is possible to use it in larger scales.- انتشار مقاله: 04-03-1397
- نویسندگان: Majid Masoumi,Ali Morad Rashidi,Mohammadmehdi Choolaei,Saeed Sadeghpour
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of System Management
- نوع مقاله: Journal Article
- کلمات کلیدی: Human Factors,Organizational Agility,organizational factors,Technological factors,Strategic Factors
- چکیده:
- چکیده انگلیسی: Nowadays, organizational agility is a subject that its study has a significant impact on the growth and improvement of organizations. The present research is carried out in order to design and explain an organizational agility development model for the North Khorasan province's organization of education. Present research in terms of purpose is applied and in terms of methodology is descriptive-exploratory. According to the theoretical hypotheses explained in the research, organizational, strategic, human, and technological factors were identified in this research as the factors explaining the organizational agility development model for the North Khorasan province's organization of education. In order to explain the research model, a standard questionnaire, developed by Sharifi and Zhang (2001), was used. The Cochran formula was used to determine the sample size and the sampling method was stratified random sampling. To analyze data, descriptive and inferential statistics methods were used so that in the inferential part, confirmatory and exploratory factor analysis tests using SPSS and LISREL were used. The results obtained from the statistical analysis at the descriptive level demonstrated that average of organizational agility, human, organizational and strategic factors are greater than the average level and average of technological factors is at the average level. At the inferential level, which used confirmatory factor analysis, the results indicated that organizational, human, strategic, and technological factors are influential on the organizational agility development. Thus, this study develops an organizational agility model based on the aforementioned factors
- انتشار مقاله: 05-10-1397
- نویسندگان: Mohammadvali Rashidi,Moslem Cherabin,Ahmad Akbari,Ali Maghool
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: polyethylene glycol,nano-composite,polyvinyl alcohol,mechanical alloying,cobalt ferrite nano-particles
- چکیده:
- چکیده انگلیسی: In this research, the effect of different biopolymers such as polyethylene glycol (PEG) and polyvinyl
alcohol (PVA) on synthesis and characterization of polymer/cobalt ferrite (CF) nano-composites by
mechanical alloying method has been systematically investigated. The structural, morphological and
magnetic properties changes during mechanical milling were investigated by X-ray diffraction (XRD),
Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field
emission scanning electron microscopy (FESEM), and vibrating sample magnetometer techniques
(VSM), respectively. The polymeric cobalt ferrite nano-composites were obtained by employing a
two-step procedure: the cobalt ferrite of 20 nm mean particle size was first synthesized by mechanical
alloying route and then was embedded in PEG or PVA biopolymer matrix by milling process. The
results revealed that PEG melted due to the local temperature raise during milling. Despite this
phenomenon, cobalt ferrite nano-particles were entirely embedded in PEG matrix. It seems, PAV is an
appropriate candidate for producing nano-composite samples due to its high melting point. In
PVA/CF nano-composites, the mean crystallite size and milling induced strain decreased to 13 nm and
0.48, respectively. Moreover, milling process resulted in well distribution of CF in PVA matrix even
though the mean particle size of cobalt ferrite has not been significantly affecetd. FTIR result
confirmed the attachment of PVA to the surface of nano-particles. Magnetic properties evaluation
showed that saturation magnetization and coercivity values decreased in nano-composite sample
comparing the pure cobalt ferrite.- انتشار مقاله: 24-06-1394
- نویسندگان: Sedigheh Rashidi,Abolghasem Ataie
- مشاهده