Papers by alireza shakeri
Journal of Management and Accounting Studies, 2020
Objective: This study aims to investigate the present situation of performance of Jihad's Uni... more Objective: This study aims to investigate the present situation of performance of Jihad's University employees of North Khorasan and providing ultimate model. Methodology: This study is descriptive_ applied, the statistical population was 80 people whom all of them were chosen due to small number of people. In order to collect the data, the librarian and internet sources such as books were used. Results: Information and data collection needed to assess the research hypothesis, the researcher made questionnaire which has 71 items is used that the experts' opinions have been applied for reliability and the Cronbach’s coefficient test was used to confirm the validity of the questionnaire and the value was 0.90. SPSS software was used to analyze the information. The single sample t-test and factorial analysis and the Freedman test were used in inferential statistics. Conclusion: The results showed that the present situation of Jihad's University has significant difference in...
علوم و تکنولوژی پلیمر, 2017
Because of wide applications of poly(ethylene oxide) (PEO) in various areas such as chemical, ele... more Because of wide applications of poly(ethylene oxide) (PEO) in various areas such as chemical, electrical and pharmaceutical industries, researchers have been focused to develop and improve the properties of this interesting polymer. To improve the mechanical and thermal properties of PEO some research works have been done. One way to improve the properties of this polymer is to add natural nanoparticles and producing the corresponding nanocomposites. In this research, a poly(ethylene oxide)/chitin nanofibrils (CFNs) nanocomposite was prepared at different CNFs loadings, and the effect of nanochitin on the properties of nanocomposite was investigated by different techniques. Nanochitin was prepared using a 1 wt% chitin suspension in water by a mechanical super-grinder, and the SEM images showed an average 50 nm diameter for the fibers obtained. Poly(ethylene oxide)/nanochitin (PEO/NFC) nanocomposites having 1, 3 and 5 wt% NFC were prepared via solution casting method using water as s...
تحقیقات علوم چوب و کاغذ ایران, 2012
To investigate the effect of acetylation and antioxidant separately and together on discoloratio... more To investigate the effect of acetylation and antioxidant separately and together on discoloration and contact angle wood plastic composite due to weathering , composite s were made using popular wood flour and high density polyethylene . the sample were exposed to natural weathering for 6 months. The results have shown that acetylation can relatively reduce the discoloration of weathered sample treatment than control sample.the antioxidant does not have any influence on color change but it seems that antioxidant could prevent partly destruction of plastic . It should be mention acetylating increased the surface contact angle befor weathering. But it could not protect the sample surface after the exposure period. So that was zero after weathering.
Properties of wood plastic composite panels made from waste sanding dusts and nanoclay
Properties of wood plastic composite panels made from waste sanding dusts and nanoclay
Separation and Purification Technology, 2021
Industrial Crops and Products, 2021
Abstract The extracted tannin from Sumac leaves (Rhus coriaria L.) as a bioresource was utilized ... more Abstract The extracted tannin from Sumac leaves (Rhus coriaria L.) as a bioresource was utilized for Non-isocyanate Polyurethanes (NIPUs) synthesis. The extracted tannin pre-reacted with dimethyl carbonate. Subsequently, NIPUs were synthesized via the reaction of carbonated tannin with hexamethylene diamine. The condition of the reaction was optimized for different parameters including tannin/DMC weight ratio, reaction time, and reaction temperature by response surface methodology (RSM). The results indicate the influence of the mentioned variables on the polyurethane synthesis yield was negative, positive, and ineffective, respectively. The structural, thermal, and mechanical properties of the synthesized materials were investigated by FTIR, MALDI-TOF, GPC, DSC, DMTA, TGA analyses, and tensile testing. The successful synthesis of NIPUs was confirmed by MALDI-TOF and FTIR spectroscopies. Tannin as a polyphenolic material contains many aromatic benzene rings. During thermal degradation due to benzene rings fusion, these rings convert to thermally stable materials and increase the char yield (36 wt% at 800 °C). Also, the synthesized NIPU demonstrated a high value of Tg (DSC: 75 °C, DMTA: 79 °C) which can be attributed to the existence of intermolecular hydrogen bonding, high crosslinked density, as well as restriction of the molecular segments mobility due to benzene rings rigidity. Finally, the Higher mechanical properties of the optimum sample confirm the efficiency of the optimization process. The results exhibited that the extracted tannin from the biobased resource can be a good alternative material for the NIPUs synthesis.
International Journal of Nanomedicine, 2020
Introduction: In recent years, the use of cost-effective, multifunctional, environmentally friend... more Introduction: In recent years, the use of cost-effective, multifunctional, environmentally friendly and simple prepared nanomaterials/nanoparticles have been emerged considerably. In this manner, different synthesizing methods were reported and optimized, but there is still lack of a comprehensive method with multifunctional properties. Materials and Methods: In this study, we aim to synthesis the copper oxide nanoparticles using Achillea millefolium leaf extracts for the first time. Catalytic activity was investigated by in situ azide alkyne cycloaddition click and also A 3 coupling reaction, and optimized in terms of temperature, solvent, and time of the reaction. Furthermore, the photocatalytic activity of the synthesized nanoparticles was screened in terms of degradation methylene blue dye. Biological activity of the synthesized nanoparticles was evaluated in terms of antibacterial and anti-fungal assessments against Staphylococcus aureus, M. tuberculosis, E. coli, K. pneumoniae, P. mirabili, C. diphtheriae and S. pyogenes bacteria's and G. albicans, A. flavus, M. canis and G. glabrata fungus. In the next step, the biosynthesized CuO-NPs were screened by MTT and NTU assays. Results: Based on our knowledge, this is a comprehensive study on the catalytic and biological activity of copper oxide nanoparticles synthesizing from Achillea millefolium, which presents great and significant results (in both catalytic and biological activities) based on a simple and green procedure. Conclusion: Comprehensive biomedical and catalytic investigation of the biosynthesized CuO-NPs showed the mentioned method leads to synthesis of more eco-friendly nanoparticles. The in vitro studies showed promising and considerable results, and due to the great stability of these nanoparticles in a green media, effective biological activity considered as an advantageous.
Journal of Membrane Science, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Food Science and Technology, 2020
Palaeogeography, Palaeoclimatology, Palaeoecology, 2019
A Neo-Tethyan upper Albian-Turonian (hemi-)pelagic carbonate succession (Sarvak Formation), acces... more A Neo-Tethyan upper Albian-Turonian (hemi-)pelagic carbonate succession (Sarvak Formation), accessible in outcrop in the Zagros, SW Iran, was investigated using sedimentology, microfacies analysis, planktonic foraminifera biostratigraphy, and carbon-isotope stratigraphy. The succession contains six biozones including Thalmaninella (Th.) appenninica, Th. globotruncanoides, Rotalipora cushmani, Whiteinella archaeocretacea, Helvetoglobotruncana Helvetica, and Marginotruncana schneegansi. Some of these biozones show variable stratigraphic positions throughout the Tethyan and Boreal realms that hinder correlation of the studied Iranian section with European reference sections. Therefore, the correlation of the existing biostratigraphic framework was complemented by carbonate carbon-isotope stratigraphy based on bulk carbonate material. Despite the low resolution of the presented carbon-isotope record, pronounced global events including the late Turonian Events, Cenomanian/Turonian Boundary (CTB) Event (OAE 2), and Albian/Cenomanian Boundary (ACB) Event can be distinguished. The δ 13 C excursions provide global synchronous time-lines for correlation. The distinguished biozones were compared among the sections regarding their stratigraphic positions relative to these timelines. The correlation tentatively suggests that the biostratigraphic datum marking the ACB is diachronous with an SE-NW trend. First appearance datum (FAD) of Th. appenninica varies from the upper Albian to the lower Cenomanian. The FAD of Th. globotruncanoides is also variable from the upper Albian to the lower Cenomanian. However, the middle Cenomanian-Turonian biozones including Rotalipora cushmani and Whiteinella archaeocretacea zones are synchronous. Elevated pCO2 contributed to the gradual increase of the SST (sea surface temperature) during the Cenomanian, and the dramatic climax at the earliest Turonian. This trend closely correlates with the change from the diachronous ACB-biozones to synchronous CTB-biozones. Possibly, increasing SSTs provided temperature-tolerance range for the species throughout different latitudes, and assisted their rapid distribution. Moreover, the warming raised the sea level from the
ABSTRACT The fillers are fine particles mainly produced from the natural minerals and used in var... more ABSTRACT The fillers are fine particles mainly produced from the natural minerals and used in various industries for different purposes. Talc is a hydrophobic filler and chemically inert; therefore, it is used in many industries. This is very important in the paper industry. In fact, compared to other fillers used in the industry, talc improves the quality of the final paper product and also, reduces the environmental problems of paper making factories. This provides many economic advantages for papermakers and causes to have more focus on the processes which improved the filler efficiency. Therefore, understanding the characteristics of talc and its improvement methods is an inevitable necessity.
Polymer Bulletin, 2010
Poly(vinyl acetate-co-butyl acrylate) latexes having oligomeric N-methylol acrylamide were prepar... more Poly(vinyl acetate-co-butyl acrylate) latexes having oligomeric N-methylol acrylamide were prepared by semi-continuous emulsion polymerization. The effects of new protective colloid and comonomer ratios on the physicochemical and colloidal properties of latexes were investigated. The changes in homopolymer and copolymer latexes were determined by measuring viscosity, particle size, molecular weight (MW), molecular weight distribution (MWD), and surface tension. " M n values of copolymer latexes were found to be lower than the MWs of the poly(vinyl acetate) and poly(butyl acrylate) homopolymers. In general, " M n and " M w values of copolymer latexes changed irregularly with increasing BuA ratio in the copolymer composition.
Journal of the Iranian Chemical Society, 2017
metal ions as well as leaching amount of the catalysis were studied by ICP-OES instrument. The ca... more metal ions as well as leaching amount of the catalysis were studied by ICP-OES instrument. The catalyst shows up to high yields for oxidation of primary and secondary primary benzylic or allylic alcohols to carbonyl compounds, especially direct imine formation in a mild, inexpensive and efficient method which can be successfully recovered from the reaction mixture and reused for several times without any remarkable reactivity loss. Effect of solvent, temperature, catalyst amount and oxygen donors along with some blank experiments to elucidation of catalyst activity was evaluated in this work. Also chemoselectivity behavior of the catalyst was investigated with some combinations.
The surface characteristics of treated pulp paper fibre were investigated usinginverse gas chroma... more The surface characteristics of treated pulp paper fibre were investigated usinginverse gas chromatography (IGC). The surface of pulp paper fibres was modifiedwith γ-aminopropyl-triethoxysilane, dichlorodiethylsilane and vinyl triethoxysilane. The effectiveness of these surface treatments was monitored by IGC adsorption curves using n-alkanes and acid-base probes. The empirical acid (KA) and base (KD) character-istics (i.e., electron donor/acceptor abilities) of untreated and treated pulp papers fibres were determined using Schultz’s method and were correlated with the surface chemical compositions determined from Fourier transform infra-red spectroscopy (FTIR) tech-nique. The results indicated that the surface of untreated pulp paper fibres had an acidic characteristic due to the electron acceptor character of the hydroxyl protons. γ-Aminopropyl triethoxysilane produced a basic surface behaviour attributed to the electron donor ability of the amino groups. Dichlorodiethylsilane prod...
Journal of Polymer Research
Bioresources, 2021
Matched sets of clear specimens of poplar and pine wood were treated with 3, 5, and 8% (v/v) aque... more Matched sets of clear specimens of poplar and pine wood were treated with 3, 5, and 8% (v/v) aqueous solutions of slow pyrolysis acid (PA) derived from date palm waste, to evaluate the effectiveness of PA in controlling mold growth on species of wood. Chemical compounds available in PA were identified by gas chromatography-mass spectrometry analysis. Treated and control specimens were contaminated with Aspergillus sp., then incubated in accordance to AWPA E24 (2017). Percentages of occupied surface by mold on each of control and treated specimen with respect to its total surface were evaluated by Image-J software. Comparisons of mean values of these determined ratios and physical examinations showed that, depending on species, the 5 and 8% water solutions of PA prohibited Aspergillus growth on tested woods. Experiments were also conducted on a matched set of small clear specimens of beech wood, impregnated by 3, 5, and 8% water solutions (v/v) of PA, using full-cell process and cont...
In this study, Cr2O3/TiO2 nanoparticles were synthesized using sol-gel method. TiO2 as one of the... more In this study, Cr2O3/TiO2 nanoparticles were synthesized using sol-gel method. TiO2 as one of the most important semiconductor materials with a variety of applications in many fields including photocatalysis and solar cells combined with Cr2O3 as a mineral material and one of the basic oxides used as pigments to improve properties such as mechanical strength, thermal stability form the Cr2O3/TiO2 nanocomposite showing attractive applications in photocatalysis and solar cells. To this end, its application in solar cells has been investigated to testify its performance. The results were promising in the case of solar cell. Cr2O3/TiO2 nanocomposite solution formed a compact layer with low defects and grain boundaries while it was sprayed as blocking layer (TiO2) in superstrate structure CZTS solar cells (Glass/FTO/TiO2/In2S3/CZTS/carbon). Compared to individual TiO2 blocking layer, the asdeposited layer showed better quality and performance. X-Ray was used to confirm synthesized nanopa...
DESALINATION AND WATER TREATMENT, 2021
This research work reports a simple and novel method to fabricate thin film nanocomposite forward... more This research work reports a simple and novel method to fabricate thin film nanocomposite forward osmosis membranes (TFN-FO). The newly designed TFN membrane was fabricated by incorporation of UiO66 NH2 nanoparticles within a polyamide thin film by using the interfacial polymerization (IP) of m-phenylenediamine/aminated (MPD/UiO66 NH2) aqueous and trimesoyl chloride (TMC) organic solution. Then, the morphology characteristics, water permeability, and removal behavior of Cr3+ ions were thoroughly evaluated. Compared with the unmodified thin film composite (TFC) membrane, the UiO66 NH2 modified TFN-U800 membrane (800 ppm nanofiller concentration) presented higher hydrophilicity and better overall FO performance. Additionally, the TFN-U800 membrane exhibited greater metal removal for heavy metal Cr3+ ions in AL-FS mode (feed solution in contact with active layer) than the control TFC membrane, arising from its improved polyamide (PA) layer characteristic. We expect that this novel tech...
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Papers by alireza shakeri