Search for: formaldehyde
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    Microwave-assisted aminomethylation of electron-rich compounds under solvent-free condition

    , Article Synthetic Communications ; Volume 30, Issue 1 , 2000 , Pages 69-72 ; 00397911 (ISSN) Mojtahedi, M. M ; Sharifi, A ; Mohsenzadeh, F ; Saidi, M. R ; Sharif University of Technology
    Marcel Dekker Inc  2000
    Electron-rich aromatic compounds react with formaldehyde and a secondary amine under solvent-free condition, in the presence of acidic alumina in a commercial microwave oven or at room temperature to produce aminomethylated products in good to excellent yields  

    Practical properties and formaldehyde emission of medium density fiberboards (MDFs) recycled by electrical method

    , Article European Journal of Wood and Wood Products ; Volume 76, Issue 4 , 2018 , Pages 1287-1294 ; 00183768 (ISSN) Moezzipour, B ; Abdolkhani, A ; Doost hoseini, K ; Ramazani Saadat Abadi , A ; Tarmian, A ; Sharif University of Technology
    Springer Verlag  2018
    In this study, the performance of the electrical method in MDF wastes recycling was determined. For investigating the practical aspect of the electrical method, the hydrothermal method as a known recycling method was studied too. The recycling process by electrical method conducted for two different time durations (2 and 4 min) at a temperature of 100 °C and recycling using the hydrothermal method was done at a temperature of 105 °C for 150 min under 4 bar pressure with subsequent refining step. Recycled fibers were analyzed by determination of the chemical composition of fibers and fiber classification. After that, laboratory MDF boards with dimensions of 35 × 35 × 12 mm3 and density of... 

    Reduced graphene oxide–melamine formaldehyde as a highly efficient platform for needle trap microextraction of volatile organic compounds

    , Article Microchemical Journal ; Volume 157 , 2020 Dorabadi Zare, F ; Allahdadlalouni, M ; Baktash, M. Y ; Bagheri, H ; Sharif University of Technology
    Elsevier Inc  2020
    A superhydrophobic extractive phase was prepared and packed in a needle trap microextraction device for extraction of volatile organic compounds, followed by their determination by gas chromatography. The superhydrophobic phase was prepared by surface modification of melamine formaldehyde (MF) sponge embedded by reduced graphene oxide (rGO). The overall properties of the modified MF along with its high sorption capacity and low cost fabrication were indicative of its feasibility to be highly suitable for extraction of organic pollutants. The determined water contact angle (>150o) from the surface of melamine formaldehyde–reduced graphene oxide (MF–rGO) revealed its high affinity toward... 

    Formalin fumigation and steaming of various composts differentially influence the nutrient release, growth and yield of muskmelon (Cucumis melo L.)

    , Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) Mustafa, G ; Ali, M. A ; Smith, D. L ; Masood, S ; Qayyum, M. F ; Ahmed, N ; Rehman, A ; Ahmad, S ; Hussain, S ; Arshad, M ; Muneer, S ; Khan, A. H. A ; Fahad, S ; Datta, R ; Iqbal, M ; Schwinghamer, T. D ; Sharif University of Technology
    Nature Research  2021
    Nutrient disorder and presence of disease-causing agents in soilless media negatively influence the growth of muskmelon. To combat these issues, use of environmentally-friendly sanitation techniques is crucial for increased crop productivity. The study was conducted under greenhouse and field conditions to investigate the effect of two different sanitation techniques: steaming and formalin fumigation on various media’s characteristics and their impact on muskmelon yield. Media: jantar, guar, wheat straw and rice hull and peat moss of 10% air-filled porosity and sanitized with formalin and steaming. Steaming of guar, jantar, and wheat straw increased the phosphorus (P) and potassium (K)... 

    Solvent-free three-component condensation reaction of aromatic ketones with aliphatic amines and formaldehyde

    , Article Journal of Chemical Research - Part S ; Issue 8 , 2000 , Pages 380-381 ; 03082342 (ISSN) Mojtahedi, M. M ; Saidi, M. R ; Sharifi, A ; Noushabadi, M ; Bolourtchian, M ; Sharif University of Technology
    Scientific Reviews Ltd  2000
    A solvent-free procedure for the synthesis of several 1-aryl-2-(dialkylaminomethyl)-prop-2-en-1-ones 3 (a-e) and 4 (a-e) is reported. Reaction of arylmethyl ketones with formaldehyde and dialkylamines, such as diethyl- or dibutylamines at room temperature in silica gel produce 3 and 4 with moderate yields  

    Formaldehyde biodegradation using an immobilized bed aerobic bioreactor with pumice stone as a support

    , Article Scientia Iranica ; Volume 18, Issue 6 , December , 2011 , Pages 1372-1376 ; 10263098 (ISSN) Ebrahimi, S ; Borghei, M ; Sharif University of Technology
    The objective of this study is the investigation of formaldehyde degradation in a bioreactor with pumice stone as a support. The reactor was tested at different synthetic wastewater concentrations with total COD of 500, 1000 and 1500 mgL, respectively, at 24 h hydraulic retention time. The effect of feed composition was tested by changing the COD TCOD FA ratio in order to analyze the impact of formaldehyde concentration. The average formaldehyde and COD removal efficiencies obtained in the reactor were 97.1% and 88%, respectively. The maximum COD and formaldehyde removal efficiencies occurred at the COD TCOD F of 41 at COD T=1000mgL. The effect of toxic shock on reactor performance was... 

    Trace determination of free formaldehyde in DTP and DT vaccines and diphtheria-tetanus antigen by single drop microextraction and gas chromatography-mass spectrometry

    , Article Journal of Pharmaceutical and Biomedical Analysis ; Volume 50, Issue 3 , 2009 , Pages 287-292 ; 07317085 (ISSN) Bagheri, H ; Ghambarian, M ; Salemi, A ; Es Haghi, A ; Sharif University of Technology
    An immersed single drop microextraction (SDME) method was successfully developed for the trace enrichment of formaldehyde from DTP and DT vaccines and diphtheria-tetanus antigen. The formaldehyde was derivatized by means of the Hantzsch reaction. The dehydropyridine derivative was extracted into a microdrop of chloroform that suspended in a 4 ml sample solution for a preset time. The microdrop was then retracted into the microsyringe and injected directly into a gas chromatography-mass spectrometry (GC-MS) injection port. Effects of different parameters such as the type of solvent, extraction time, stirring rate, and temperature were studied and optimized. The limit of detection was 0.22... 

    Environmental Monitoring of Formaldehyde in Biologics Production Areas Using Solid-Phase Microextraction Coupled to Gas Chromatography Mass Spectrometry

    , M.Sc. Thesis Sharif University of Technology Allahdad Lalouni, Misagh (Author) ; Bagheri, Habib (Supervisor) ; Eshaghi, Ali (Supervisor)
    During the recent years, manufactures and industries have paid attention to occupational health and safety of their employees. Formaldehyde is known as a probable carcinogenic agent and its large consumption made industries to consider it as a risk factor for occupational health. At vaccine production industries, Formaldehyde is used as disinfectant and stabilizer. In this study, a solid-phase microextraction (SPME) method based on kinetic and equilibrium calibration strategies was developed for monitoring of formaldehyde in the biologics production areas. The application and feasibility of three different sol-gel based SPME fibers with different polarities have been investigated. Two... 

    Shaping of Laser Pulse for Molecular Dissociation

    , M.Sc. Thesis Sharif University of Technology Rasti, Soroush (Author) ; Saddighi Bonabi, Rasoul (Supervisor)
    In this project, ionization and dissociation of nitrogen, methane and formaldehyde molecules through interaction by intense femto-second lasers have been investigated. The optimum shape of laser pulses for dissociation of methane and formaldehyde molecules for controlling the dissociation paths into desired products are obtained. Based on time dependent density functional theory and quantum optimal control theory, the calculations are carried out in intensities at the range of 1014-1016 Wcm-2 with pulse durations of 4 -20fs. Octopus package is used as a powerful computational program. By using, quantum optimal control theory, optimum laser pulses with manipulation of amplitude, phase and... 

    A Novel Magnetic Molecularly Imprinted Polymers Nanoparticle as Extracting Medium For Micro-Solid Phase Extraction

    , M.Sc. Thesis Sharif University of Technology Yahya Baktash, Mohammad (Author) ; Bagheri, Habib (Supervisor)
    This thesis cantain two section. In the first section a novel extracting medium based on magnetic molecularly imprinted polymers (MIPs) nanoparticles was synthesized by chemical polymerization for micro-solid phase extraction. In this work, the modified chitosan magnetite nanoparticles (MNP-CS) was synthesized by co-precipitating Fe2+ and Fe3+ in the chitosan solution [1,2]. The characteristic properties of Fe3O4@MIPs nanoparticles were determined using Fourier transform infrared spectrometer. Extraction efficiency of the novel extracting medium was compared with MNP-CS sorbents for the determination of RhB in aqueous samples, via quantification by spectrofluorimetry. The obtained results... 

    Mechanical properties and structure of solvent processed novolac resin/layered silicate: Development of interphase region

    , Article RSC Advances ; Volume 5, Issue 98 , Jun , 2015 , Pages 80875-80883 ; 20462069 (ISSN) Jahanmard, P ; Shojaei, A ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Composites of phenol-formaldehyde (PF) resin with Closite Na+ and Closite 30B up to 20 wt% loadings were prepared by solution mixing. Tensile testing showed that both pristine and organically modified clays increased considerably the mechanical properties of PF resin at 2.5 wt% loading followed by marginal improvement or even sacrificed properties at high loadings. DMA and DSC analyses suggested development of a highly crosslinked and well adhered interphase around silicate layers. A novel three-phase model considering the interphase region was proposed to predict composite modulus. The model was successfully employed to correlate morphological characteristics and mechanical properties of... 

    A single–step synthesized supehydrophobic melamine formaldehyde foam for trace determination of volatile organic pollutants

    , Article Journal of Chromatography A ; Volume 1525 , 2017 , Pages 10-16 ; 00219673 (ISSN) Bagheri, H ; Zeinali, S ; Baktash, M. Y ; Sharif University of Technology
    Superhydrophobic materials have attracted many attentions in recent years while their application in sample preparation remained almost intact. In this project, a rough surface of melamine formaldehyde foam was silanized by chemical deposition of trichloromethylsilane to form a highly porous and superhydrophobic material, presumably a suitable medium for extracting non–polar compounds such as benzene and its methyl derivatives. The prepared sorbent was packed in a needle for the headspace needle–trap microextraction of benzene, toluene, ethylbenzene and xylenes (BTEX). Major parameters associated with the extraction/desorption processes were considered for optimization. Under the optimized... 

    Preparation and Application of Superhydrophobic Melamine Formaldehyde Modified by Graphene Sorbent for Extraction of Chlorobenzenes from Aqueous Samples by Needle-trap Device

    , M.Sc. Thesis Sharif University of Technology Dorabadi Zare, Farzaneh (Author) ; Bagheri, Habib (Supervisor)
    Superhydrophobic surfaces have attracted much attention in recent years due to their unique properties. Artificial superhydrophobic surfaces can be fabricated by employing chemical modifying a hierarchical structured surface (micro- and nanostructures) with a low surface free energy material. In this report, we used a simple one-step coating process to prepare superhydrophobic sorbents with a large surface area. Surface chemistry and porosity are fundamental parameters for an efficient sorbent capable of extracting low levels of analytes. Considering physical and chemical peroperties of chlorobenzenes, superhydrophobic materials make to be good sorbents. So in this project melamine... 

    A Superhydrophobic Melamine Formaldehyde Sorbent for Micro Extraction of Pollutants from Aquatic Media

    , M.Sc. Thesis Sharif University of Technology Zeinali, Shakiba (Author) ; Bagheri, Habib (Supervisor)
    In this project, melamine formaldehyde was chosen as initial substrate for its high porosity. Then for having superhydrophobic surface, surface functional groups were silanized and deactivated as a result. It was assumed that high porosity of prepared sorbent and its nonpolar nature, can increase extraction efficiency. To study extraction efficiency of the prepared sorbent, it was filled inside a needle and used for needle-trap head-space extraction of BTEX (abbreviation for Benzene, Toluene, Ethylbenzene and Xylenes). Needle packed with sorbent was held on headspace of sample containing BTEX and head- space was pumped with a peristaltic pump. Pumping introduces fresh sample to sorbent... 

    A combined micro-solid phase-single drop microextraction approach for trace enrichment of volatile organic compounds

    , Article Analytical Methods ; Volume 7, Issue 16 , Jun , 2015 , Pages 6514-6519 ; 17599660 (ISSN) Bagheri, H ; Zare, M ; Piri Moghadam, H ; Es haghi, A ; Sharif University of Technology
    Royal Society of Chemistry  2015
    An attempt was made to combine μ-solid phase extraction and headspace single drop microextraction techniques and use their advantages for trace determination of some volatile organic compounds in aqueous samples. After performing the two-step preconcentration approach, the desired analytes were determined by gas chromatography-mass spectrometry. A resorcinol-formaldehyde-based xerogel was used as the extraction medium in the μ-solid phase extraction (μ-SPE) method. Then, the extracted BTEX was eluted with a rather large amount of methanol. To remove the laborious process including solvent evaporation and further reconstitution, which is usually accompanied by loss of analytes and accuracy,... 

    Inactivation methods for whole influenza vaccine production

    , Article Reviews in Medical Virology ; Volume 29, Issue 6 , 2019 ; 10529276 (ISSN) Sabbaghi, A ; Miri, S. M ; Keshavarz, M ; Zargar, M ; Ghaemi, A ; Sharif University of Technology]
    John Wiley and Sons Ltd  2019
    Despite tremendous efforts toward vaccination, influenza remains an ongoing global threat. The induction of strain-specific neutralizing antibody responses is a common phenomenon during vaccination with the current inactivated influenza vaccines, so the protective effect of these vaccines is mostly strain-specific. There is an essential need for the development of next-generation vaccines, with a broad range of immunogenicity against antigenically drifted or shifted influenza viruses. Here, we evaluate the potential of whole inactivated vaccines, based on chemical and physical methods, as well as new approaches to generate cross-protective immune responses. We also consider the mechanisms by... 

    Resorcinol-formaldehyde xerogel as a micro-solid-phase extraction sorbent for the determination of herbicides in aquatic environmental samples

    , Article Journal of Separation Science ; Volume 38, Issue 13 , 2015 , Pages 2305-2311 ; 16159306 (ISSN) Es Haghi, A ; Zare, M ; Piri Moghadam, H ; Bagheri, H ; Sharif University of Technology
    In this study, organic aerogels were synthesized by the sol-gel polycondensation of mixed cresol with formaldehyde in a slightly basic aqueous solution. Carbon aerogels and xerogels are generated by pyrolysis of organic aerogels. The novel sol-gel-based micro-solid-phase extraction sorbent, resorcinol-formaldehyde xerogel, was employed for preconcentration of some selected herbicides. Three herbicides of the aryloxyphenoxypropionate group, clodinafop-propargyl, haloxyfop-etotyl, and fenoxaprop-P-ethyl, were extracted from aqueous samples by micro-solid-phase extraction and subsequently determined by gas chromatography with mass spectrometry. The effect of different parameters influencing the... 

    Implementing a superhydrophobic substrate in immersed solvent–supported microextraction as a novel strategy for determination of organic pollutants in water samples

    , Article Ecotoxicology and Environmental Safety ; Volume 163 , 2018 , Pages 104-110 ; 01476513 (ISSN) Baktash, M. Y ; Asem Yousefi, A ; Bagheri, H ; Sharif University of Technology
    Academic Press  2018
    In this research, a new approach for extraction and determination of polycyclic aromatic hydrocarbons from sea and rain water samples was developed by implementing a superhydrophobic substrate and consuming the least amount of solvent. This version of solvent–supported microextraction enabled us to perform the procedure in the immersion mode with the slightest troubles arising from water leakage into the gas chromatography. The superhydrophobic property leads to the fixation of extracting solvent on the substrate surface during water sampling. To prepare a superhydrophobic substrate, a piece of melamine foam was coated by tannic acid and silica nanoparticles using methyltrimethoxysilane and... 

    Resorcinol-Formaldehyde Xerogel for Analysis of Environmental Pollutant in Aqueous Sample

    , M.Sc. Thesis Sharif University of Technology Zare, Maryam (Author) ; Bagheri, Habib (Supervisor) ; Es-haghi, Ali (Supervisor)
    In this study, a new resorcinol-formaldehyde xerogel was synthesized based on sol-gel technology and employed as a sorbent for micro solid phase extraction (µ-SPE) of BTEX and some selected pesticides from aqueous samples.
    In the first part, a µ-SPE method in combined with headspace solvent microextraction (HS-SME) along with gas chromatography- mass spectrometry detection (GC–MS) was developed for the analysis of BTEX in aqueous samples. In our knowledge, this is for the first time that these two different extraction methods has been coupled to maximize the advantage of each extraction method. Influential parameters such as the peristaltic pump flow rate, extraction volume, extraction... 

    Experimental Study of Formaldehyde Decomposition Using a Plasma - Catalyst Hybrid Reactor as a Potential Voc Removal Technique

    , M.Sc. Thesis Sharif University of Technology Nemati Tamar, Amin (Author) ; Hamzeh Louyan, Tayyebeh (Supervisor) ; Khani, Mohammad Reza (Supervisor)
    Volatile organic compounds (VOCs) has harmful environmental and health effects and appropriate processes are needed to remove them from industrial and indoor environments. In this study, formaldehyde as one of the most toxic VOCs was investigated. Various methods have been developed to remove formaldehyde, however due to the to their low removal efficiencies, secondary pollution, and low energy efficiency, development of alternative methods will be beneficial. In recent years, the use of a combination of non-thermal plasma and catalyst technologies, called plasma-catalytic hybrid reactors, has provided significant results in the fields of chemical synthesis and removal of pollutants. In the...