| 91. |
- Abdelhameed, A. H., et al.
(författare)
-
Geant4-based electromagnetic background model for the CRESST dark matter experiment
- 2019
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 79:10
-
Tidskriftsartikel (refereegranskat)abstract
- The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) dark matter search experiment aims for the detection of dark matter particles via elastic scattering off nuclei in CaWO4 crystals. To understand the CRESST electromagnetic background due to the bulk contamination in the employed materials, a model based on Monte Carlo simulations was developed using the Geant4 simulation toolkit. The results of the simulation are applied to the TUM40 detector module of CRESST-II phase 2. We are able to explain up to (68 +/- 16)% of the electromagnetic background in the energy range between 1 and 40 keV.
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| 92. |
- Abdelhamid, Muhammad, 1987, et al.
(författare)
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Electropolymerisation of N-Ethylanilinium Trifluoroacetate Ionic Liquid into Poly(N-Ethylaniline) and Control of its Morphology
- 2017
-
Ingår i: Australian Journal of Chemistry. - 1445-0038 .- 0004-9425. ; 70:9, s. 985-989
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the electropolymerisation of pre-synthesised N-ethylanilinium trifluoroacetate, a protic ionic liquid (PIL), was carried out. The PIL served as the monomer precursor, solvent, and supporting electrolyte for the polymerisation process, and no additional acid was required due to the protic nature of the PIL. Two different morphologies of the poly(N-ethylaniline) were achieved by using different electropolymerisation approaches and the resultant films were soluble in the PIL precursor as well as a wide range of organic solvents. The use of anilinium based PILs, as polymerisation precursors, promises a greener approach for the production of polyanilines, as well as highly processable polymers.
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| 93. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
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A novel active bionanocomposite film incorporating rosemary essential oil and nanoclay into chitosan
- 2012
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774. ; 111:2, s. 343-350
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Tidskriftsartikel (refereegranskat)abstract
- Montmorillonite (MMT) nanoclay and rosemary essential oil (REO) were incorporated into chitosan film to improve its physical and mechanical properties as well as antimicrobial and antioxidant behavior. The MMT weight percent relative to chitosan was varied from 1 to 5 and was activated by three REO levels (0.5%, 1%, and 1.5% v/v), and their impact on physical, mechanical, and barrier properties of the chitosan films was investigated. Total phenolic and antimicrobial activity were also evaluated. Microstructure of chitosan/MMT–REO nanocomposites was characterized through X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that incorporating MMT and REO into chitosan improves water gain, water vapor permeability, and solubility of the chitosan film by more than 50%. It was also shown that the combined effect of clay and REO improves significantly the tensile strength and elongation of chitosan (p < 0.05). The XRD and FTIR results confirmed that the improvements are related to the MMT exfoliation and good interaction between chitosan and MMT in the presence of REO. Antimicrobial properties of the films also improved by REO incorporation in 1.5% v/v.
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| 94. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
-
Carboxymethyl cellulose-agar biocomposite film activated with summer savory essential oil as an antimicrobial agent
- 2019
-
Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 126, s. 561-568
-
Tidskriftsartikel (refereegranskat)abstract
- Carboxymethyl cellulose (CMC)-agar biocomposite film was developed by a solvent casting method and the effects of summer savory essential oil (SSEO) at 0.5, 1.0 and 1.5% v/v on antimicrobial, microstructural, mechanical and optical properties as well as water sensitivity of the films were studied. Results showed that incorporation of SSEO into the biocomposite film developed active films with good antimicrobial agent growth inhibition activity against Gram-positive bacteria (S. aureus, B. cereus and L. monocytogenes) and less powerfully against Gram-negative bacteria (E. coli). Addition of the SSEO at 1.0 and 1.5% increased microstructural heterogeneity of the films and hence significantly (p < 0.05) increased water vapor permeability of the films while reducing their tensile strength. In contrast, mechanical flexibility and surface hydrophobicity of the films was significantly (p < 0.05) improved as a function of SSEO addition. The active films showed substantially lower swelling ratio compared to the CMC-agar film when 1.5% SSEO was added, but the transparency of the films was reduced. Finally, the results showed that SSEO can act as an antimicrobial agent in combination with CMC-agar film. However, it modifies properties of the film depending on the applied concentration.
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| 95. |
- Abdollahi, Mehdi, 1985
(författare)
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Comparing physico-mechanical and thermal properties of alginate nanocomposite films reinforced with organic and/or inorganic nanofillers
- 2013
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 32:2, s. 416-424
-
Tidskriftsartikel (refereegranskat)abstract
- Montmorillonite (MMT) and cellulose nanoparticles (CNP) were added to alginate biopolymer to compare the properties of bionanocomposites reinforced with different organic and inorganic nanofillers in various loading contents (1, 3, and 5 wt%). Both MMT and CNP decreased the water solubility (WS) of the films. However, at all filler contents the WS of the alginate/MMT (84–61%) nanocomposites was significantly (P < 0.05) lower than that of alginate/CNP films (95–77%). Surface hydrophobicity of the nanocomposites showed a great improvement (83%) with crystalline hydrophobic CNP addition, while MMT made films' surface more hydrophilic. The addition of both nanoreinforcements similarly caused a reduction in the water vapor permeability of the alginate-based nanocomposites. Due to the similar polysaccharide structures and good interfacial interactions, the TS and E of the nanocomposite films improved with an increase in CNP content and reached a maximum at the highest loading level (5 wt%). However, when the content of MMT went beyond 1 wt% nanocomposites, a decrease in the TS was observed. Finally, these results propose that organic CNP more than ability to make a fully renewable and natural nanocomposites may also introduce some other advantages compared to inorganic nanoclay fillers when added to carbohydrate biopolymers.
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| 96. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
-
Dynamic rheological, microstructural and physicochemical properties of blend fish protein recovered from kilka (Clupeonella cultriventris) and silver carp (Hypophthalmichthys molitrix) by the pH-shift process or washing-based technology
- 2017
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 229, s. 695-709
-
Tidskriftsartikel (refereegranskat)abstract
- This study aimed to evaluate how blending pH-shift produced protein isolates from gutted kilka (Clupeonella cultriventris) and silver carp (Hypophthalmichthys molitrix) affected dynamic rheological and chemical properties of the proteins as well as microstructural and physico-mechanical properties of produced gels. Studied variables were protein solubilization pH (acid vs. alkaline) and blending step (before or after protein precipitation). Comparisons were made with conventionally washed minces from kilka and silver carp fillets; either alone or after blending. Rheological studies revealed that blending alkali-produced protein isolates before precipitation resulted in rapid increase of G′ reflecting the formation of intermolecular protein-protein interactions with higher rate. Furthermore, blending of alkali-produced protein isolates and washed minces, respectively, of kilka and silver carp improved physico-mechanical properties of the resultant gels compared to pure kilka proteins. However, the pH-shift method showed higher efficacy in development of blend surimi at the same blending ratio compared to the conventional washing.
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| 97. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
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Effect of microbial transglutaminase and setting condition on gel properties of blend fish protein isolate recovered by alkaline solubilisation/isoelectric precipitation
- 2019
-
Ingår i: International Journal of Food Science and Technology. - : Wiley. - 1365-2621 .- 0950-5423. ; 54:3, s. 762-770
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of microbial transglutaminase (M‐TGase) (0–0.6 units g−1 sample) and setting condition (25 °C/180 min, 30 °C/120 min, 35 °C/60 min and 40 °C/30 min) on gel properties of blend protein isolate of gutted kilka and silver carp was studied. The protein isolate provided a good substrate for M‐TGase activity so that a low amount of M‐TGase (0.2 unit g−1 sample) substantially improved textural properties and water holding capacity (WHC) of the gels. Breaking force of the gels was positively affected by M‐TGase up to 0.6 unit g−1 sample, but it negatively affected their WHC. Prior setting at 25–35 °C increased the breaking force of proteins compared to directly heated gel, resulting in maximum breaking force at 35 °C/60 min. However, the setting at 40 °C/30 min caused proteolysis, which was reflected in higher amounts of TCA‐soluble peptides and gel weakening. Denser microstructure and higher myosin heavy chain polymerisation observed in the gels which experienced the setting was well correlated with improvement in textural properties.
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| 98. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
-
Effect of stabilization method and freeze/thaw-aided precipitation on structural and functional properties of proteins recovered from brown seaweed (Saccharina latissima)
- 2019
-
Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 96, s. 140-150
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Tidskriftsartikel (refereegranskat)abstract
- - Structural, functional and nutritional properties of protein recovered from brown seaweed, S. latissima with alkaline solubilization/isoelectric precipitation as a function of different post-harvest stabilization methods were studied. The latter included freezing at −20 °C/-80 °C, oven-drying, sun-drying, freeze-drying and ensilaging. Also, the efficacy of freeze/thaw-aided precipitation (F/T) in improving protein recovery of the process was evaluated. The freeze-dried, oven-dried, and −20 °C frozen seaweeds resulted in significantly higher protein yield than the −80°C-frozen, sun-dried and ensiled biomasses. F/T increased protein precipitation and doubled total protein yield. Sun-drying and −20°C-freezing caused extensive protein degradation as revealed by SDS-PAGE and HP-SEC, while oven-drying altered the seaweed protein structure with less α-helices. Functional properties of the seaweed proteins were remarkably affected by stabilization condition and F/T, but nutritional value of the proteins was only dependent on stabilization method. Thus, to efficiently recover seaweed proteins, its post-harvest stabilization condition must be carefully chosen based on the final application of the proteins. © 2019 The Authors
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| 99. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
-
Improvement of active chitosan film properties with rosemary essential oil for food packaging
- 2012
-
Ingår i: International Journal of Food Science and Technology. - : Wiley. - 1365-2621 .- 0950-5423. ; 47:4, s. 847-853
-
Tidskriftsartikel (refereegranskat)abstract
- Rosemary essential oil (REO) was used to develop an active film from chitosan. The effects of REO concentration (0.5, 1.0 and 1.5% v/v) on film properties were studied by measuring the physical, mechanical and optical properties of the REO‐loaded films. Scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy were used to study microstructure and the interaction of the chitosan‐based films. The solubility and water gain of the chitosan film decreased about 25% and 85%, respectively, by REO incorporation, up to 1.5% v/v, because of the interaction between hydrophilic groups of chitosan and REO as confirmed by FTIR. It was determined that REO improved the transparency of the films from 4.97 in neat chitosan up to 7.61; moreover, it reduced the films’ light transmission in UV light more than 25%. Films containing REO showed more antibacterial activity and total phenol content. The films containing REO showed potential to be used as active film in food preservation.
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| 100. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
-
Influence of chitosan/clay functional bionanocomposite activated with rosemary essential oil on the shelf life of fresh silver carp
- 2014
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 1365-2621 .- 0950-5423. ; 49:3, s. 811-818
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Tidskriftsartikel (refereegranskat)abstract
- A combination of chitosan biopolymer, nanoclay and rosemary essential oil was prepared as a functional bionanocomposite (FBN). Its ability to improve the shelf life of refrigerated (4 ± 1 °C) silver carp fillets was studied. The fresh fillets were left untreated as a control or coated with chitosan, chitosan/clay bionanocomposite and chitosan/clay/rosemary essential oil (Ch/clay/REO) FBN. Then, they were evaluated for chemical, microbial and sensory properties over 16‐day storage. The samples coated with the FBN had the lowest pH and total volatile basic nitrogen. Ch/clay/REO coating efficiently retarded lipid oxidation by decreasing peroxide, free fatty acid and thiobarbituric acid production in the samples. The coating also reduced total viable and psychrotrophic count of the fillets more than 1.5 log by the end of storage.
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