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51.
Mohammad Ali Taj Saeed Kazemi Najafi Ghanbar Ebrahimi 《Holz als Roh- und Werkstoff》2009,67(2):135-140
Withdrawal and lateral resistance of wood screw in three hardwood species of beech (Fagus orientalis Lipsky.), hornbeam (Carpinus betulus) and poplar (Populus deltoides 75/51) were studied. Measured values of ultimate withdrawal resistance of wood screws were compared with predicted values. Moreover, shear strength parallel to the grain of wood as an input parameter of the expression given by Eckelman was measured. Measured values of lateral resistance of wood screw connection were compared with predicted values of yield limit equations, and dowel bearing strength of wood as the input parameter of yield limit equations was measured. Results show that the expression by Eckelman gives a more accurate prediction than the expression given in NDS. Furthermore, yield limit equations accurately predicted observed yield mode, and in the three species lateral resistance was predicted lower than the measured values. 相似文献
52.
Ghonche Rassam Mohammad Ghofrani Hamid Reza Taghiyari Behnam Jamnani Mohamad Ali Khajeh 《Holz als Roh- und Werkstoff》2012,70(5):595-600
The aim of this study was to investigate the effect of nano-silver treatment on some physical and mechanical properties of compressed low density wood species. Wood specimens were prepared from spruce (Picea abies), impregnated with water or nano-silver solution by empty cell process and compressed through radial direction in a hot press. The results showed that by nano-silver treatment, the spring back, bending strength (modulus of rupture) and impact load resistance were improved significantly. The best results for spring-back (0.04%) were seen in the nano-silver impregnated specimens that were compressed at 150°C for 4 hours. The modulus of rupture (MOR), modulus of elasticity (MOE) and impact load resistance in nano-silver impregnated densified specimens were gained for 53%, 41.2% and 175.7%, respectively (in comparison with controls). The maximum amounts of impact load resistance belonged to the nano-silver impregnated specimens which were compressed at press conditions of 150°C for 4 hours, showing the high ability of these specimens against high impact loads such as earthquake loads. An upcoming research (consisting of durability tests) will be done for evaluating the suitability of nano-silver impregnated densified spruce wood for exterior uses. 相似文献
53.
54.
Barzegar Hassan Alizadeh Behbahani Behrooz Mehrnia Mohammad Amin 《Food science and biotechnology》2020,29(5):717-728
Food Science and Biotechnology - The instability and strong flavor or odor of essential oils (EO) limit their direct incorporation into food products. In this study, the antioxidant and... 相似文献
55.
Mohammad Fattahi Vahideh Nazeri Laura Torras-Claveria Fatemeh Sefidkon Rosa M. Cusido Zabihollah Zamani Javier Palazon 《Food chemistry》2013
Dracocephalum kotschyi Boiss. (Lamiaceae) is an aromatic and perennial herb endemic to Iran with interesting pharmacological and biological properties. The flavonoids luteolin-7-O-glucoside, apigenin-7-O-glucoside (cosmosiin), luteolin 3′-O-β-d-glucuronide, luteolin, apigenin, cirsimaritin, isokaempferide, penduletin, xanthomicrol, calycopterin and the polyphenol rosmarinic acid were identified among 13 natural populations of the plant by ESI–MS, LC–DAD and LC–DAD–ESI-MS. The plant extracts containing the identified compounds showed significant antioxidant activity, which was correlated with the flavonoid content. Additionally, leaf and stem size and geographical variability among the studied populations were correlated with flavonoid accumulation. Canonical correlation analysis was used to find a relationship between plant dimensions and phytochemical composition, and the plants with the lowest growth indices were found to have the highest levels of methoxylated flavonoids. 相似文献
56.
Seyed Mohammad Bagher Hashemi 《International Journal of Food Science & Technology》2018,53(3):564-570
The effects of pulsed and continuous ultrasound treatment on microbiological and physiological quality of Mirabelle plum fruit were investigated. Freshly harvested Mirabelle plum was treated with 30‐kHz pulsed and continuous ultrasound at 20 °C for 0, 15, 30, 45 and 60 min and subsequently stored at 4 °C for 10 days. The total count of bacteria, total fungi, decay index, titratable acidity (TA), total soluble solids (TSS), colour, texture, ascorbic acid content and total phenolics was measured. The results showed that pulsed and continuous ultrasonic treatment significantly (P < 0.05) reduced the number of microorganisms and improved the quality of Mirabelle plums during storage. Increasing pretreatment time enhanced the positive effects of pulsed and continuous ultrasound. Also, in terms of the total count of bacteria, total fungi, titratable acidity and total phenolics, the pulsed and continuous ultrasound did not show a significant difference (P < 0.05). However, pulsed ultrasound was better compared to continuous mode in preservation of TSS, colour, texture and ascorbic acid content of the fruit during storage. Our results demonstrated that pulsed ultrasound is an appropriate method for improving safety and maintaining the quality of Mirabelle plum fruit. 相似文献
57.
The aim of this work was the fabrication of cotton fabric with multifunctional properties such as photochromic, hydrophobicity, antibacterial, and ultraviolet (UV) blocking. In this regard, a mixture of silica nanoparticles with spirooxazine as a photochromic dye first applied on the cotton fabric, and then, the fabric surface was coated with an alkylsilane compound. The homogenous distribution of silica and silica/spirooxazine hybrid on the cotton fibers was established by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray mapping. X-ray diffraction patterns confirmed the amorphous nature of the hybrid on the treated cotton fabric. The photochromic effect of the fabrics was measured after 5-min sunlight irradiation. Other characteristics of treated fabrics, such as antibacterial activity, hydrophobic properties, and UV-blocking activity, were also assessed. The results indicated that adding silica nanoparticles to spirooxazine had a tangible effect on photochromic activity of treated cotton fabrics and its photochromic performance was higher than that of the photochromic dye. The fabric showed stable hydrophobicity with static water contact angle values of 141.2° ± 1°. Moreover, the coated cotton fabric demonstrated proper antibacterial properties and UV-blocking activity. 相似文献
58.
Mohd Yusuf Shafat Ahmad Khan Mohd Shabbir Faqeer Mohammad 《Journal of Natural Fibers》2017,14(4):597-607
Environmental issues inspire the revival of natural dyes that exhibit better biodegradability and more compatibility over synthetic ones. This research is aimed to investigate the effect of color and fastness properties on wool yarn substrate with natural anthraquinone colorants extracted from madder roots using gallnut (Quercus infectoria) extract as anchoring agent. Prior to the dyeing with Indian Madder (Rubia cordifolia), wool fibers were pre and post-treated with different concentrations of gallnut extract (viz 1–5% o.w.f) to get a broad range of beautiful and color fast shades. The feasibility of gallnut extract as an anchoring agent and its effect on color strength and color fastness to light, rubbing, and washing was investigated. Results of color characteristics showed that the color coordinates of the dyed samples were situated in the red-yellow quadrant of the CIELabcolor space. Bio-mordanting with gallnut extract produced shades of practically acceptable color depth, color fastness to light, washing and rubbing. Pre-treatment with gallnut extract is dominated over post-treatment in terms of better colorimetric and fastness results. 相似文献
59.
Iman Golpour Moein Zarrin Nejad Reza Amiri Chayjan Ali Mohammad Nikbakht Raquel P. F. Guiné Majid Dowlati 《Sensing and Instrumentation for Food Quality and Safety》2017,11(1):1-11
This work aimed to investigate the drying behavior of melon seed during combined fluidized bed-microwave drying system. Three drying air temperatures (40, 55 and 70 °C), three microwave powers (270, 450 and 630 W) and three air velocities (0.8, 1.5 and 2.3 m/s) were tested. Five mathematical models were selected to fit the experimental data for drying kinetics, and the results revealed that the Aghbashloo et al. model exhibited, in all cases, the best performance in fitting the experimental data (R2 varying from 0.99088 to 0.99998; χ2 from 0.00000 to 0.00185 and RMSE from 0.02289 to 0.82316). Calculated values of moisture diffusivity for dried melon seed varied from a minimum of 6.51 × 10?10 to a maximum of 6.59 × 10?9 m2/s under the tested drying conditions. Moisture diffusivity values increased as air temperature and microwave power was increased. Shrinkage values were calculated and found to vary in the range from 46.99 to 15.09 %. 相似文献
60.
Natural products have been in use long before the introduction of modern drug therapies and are still used in various communities worldwide for the treatment of anterior eye disease. The aim of this review is to look at the current non-pharmaceutical modalities that have been tried and assess the body of existing evidence behind them. This includes alternative medicine, existing non-pharmaceutical therapy and more recent low and high tech solutions.A detailed search of all available databases including MEDLINE, Pubmed and Google was made to look for English-language studies for complementary and alternative treatment modalities (CAM), natural therapies and new modalities for anterior eye disease such as blepharitis, dry eye and microbial keratitis. We have included a broad discussion ranging from traditional treatments like honey and aloe vera which have been used for centuries, to the more recent technological advances like Intense Pulsed Light (IPL), LipiFlow and photoactivated chromophore for corneal cross linking in infectious keratitis (PACK-CXL).Alternative management strategies may have a role in anterior eye diseases and have a potential in changing the way we currently approach them. Some of the available CAM could play a role if incorporated in to current management practices of not only chronic diseases like blepharitis and dry eye, but also acute conditions with significant morbidity like microbial keratitis. Further large-scale randomized control trials stratified by disease severity are required to improve our understanding and to evaluate the use of non-pharmaceutical therapy against current practice. 相似文献