http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Power consumption and mixing time in rheologically complex fluids by a two-bladed impeller
Sarra Youcefi,Abdelkader Youcefi 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2
This study investigates the power consumption and mixing time of a two-bladed stirrer during the mixing of viscoelastic fluids in thelaminar region of flow. For the rheological part, we use a polymer with low-concentration aqueous solutions that present viscoelasticbehavior. The rheological study performed on polyacrylamide solutions shows the viscoelastic behavior of the generalized “Kelvin–Voigt” model. The power consumption for the viscoelastic fluids is greater than that needed to mix Newtonian fluids at the same Reynoldsnumber. The mixing time is found to depend strongly on the viscoelasticity of the solutions.
Sarra Aouadj,Soraya Zebirate,Rachid Smail,Fethi Saidi 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.3
The exploitation of fossil fuels is causing global warming whose negative effects have recently been felt all over the world. Therefore, the search for new sources of energy, renewable and respectful of the environment is crucial for manufacturers. The concept of Best Available Techniques (BAT) presents an adequate solution for manufacturers, for the control, elimination or reduction of the harmful impacts of their activities on the environment. This concept, known as Integrated Pollution Prevention and Control (IPPC), was introduced and imposed from 1996 in Europe. This paper aims to introduce the possibility of transferring the IPPC approach and BAT concepts to Algeria. Therefore, the main objective is to propose some recommendations to optimize the technical and environmental performance of hybrid solar-gas systems, by treating as a case study the first hybrid solar-gas power plant SPPI (Solar Power Plant One) near Hassi R’mel in the south of Algeria. A gap analysis of the Algerian environmental policy compared to the IPPC system, and an assessment of technical and environmental performance of the "SPPI" plant in terms of regulation and BAT are developed in our study.
Sarra Said,Mohamed Hamdaoui,Walid Sahraoui 한국섬유공학회 2023 Fibers and polymers Vol.24 No.1
This paper presents the study of the application of direct dyes on pre-treated cotton jersey knitted fabric using an experimentalsystem based on the capillary rise technique. The developed device ensures the vertical suspension of a cloth surface incontact with a dyeing bath and allows the capillary rise of the dye bath in the textile structure. A series of experiments werecarried out using cotton jersey knitted fabric as textile fabric model and the direct dyes bath (wetting agent, salt, sodiumcarbonate and direct dye) as wicking liquids by using an electronic microbalance. A mathematical model was developedto interpret the experimental data in terms of kinetic parameters of the absorbed dye bath amount and the diffusion of themolecule into the cotton jersey knitted fabric. The results show that the double-exponential kinetics model and the simplifiedCrank solution to Fick’s second law equation are in reasonable agreement with experimental data of the absorbed dye bathamount and the diffusion of the molecule of dye into the cotton jersey knitted fabric, respectively.
Aloui Sarra,Ghazouani Tesnime,Raboudi Faten,Talbi Wafa,Vanden Broeck Jozef,Salghi Rachid,Fattouch Sami 한국곤충학회 2022 Entomological Research Vol.52 No.4
The enzyme phenoloxidase (PO) plays an essential role in insect immune defense. Phenolic compounds sharing structural homology with PO substrates could act as substrate analogues, and may interfere with insect physiological process, thus, leading to their control. Herein, the bioinformatic molecular docking was used to predict the interaction of the crystal 3D structure of the insect Manduca sexta PO (PDB: 3HHS) with the antiseptic 4 hexylresorcinol (4-Hr). The method was firstly validated using phenylthiourea (PTU) as reference ligand. Data demonstrated the ability of the 4-Hr to bind to M. sexta PO with binding energy score ΔG=372,285 Kcal/mol indicative of a plausible affinity to active site of the enzyme, nevertheless, the affinity of PTU was stronger with a binding energy of ΔG=462.173 Kcal/mol. Furthermore, biochemical in vitro assays confirmed the behavior of 4-Hr as substrate-analog when binding to the active site of the insect PO leading to its competitive inhibition. This is the first report demonstrating the molecular bases of the usefulness of hexylresorcinol as a promising insecticide. Further investigations could emphasize synergistic effects of 4-Hr with other insecticides in integrated pest management (IPM) programs.
Ben Hmad Halima,Gara Sonia,Khlifi Sarra,Ben Jemaa Houda,Ben Slama Fethi,Aouidet Abdallah 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.1
Metabolic syndrome is a serious consequence of obesity characterized by increased cardiovascular risk factors such as hypertension, dyslipidemia, and glucose intolerance. While diets enriched with natural antioxidants showed beneficial effects on oxidative stress, blood pressure, and serum lipid composition, diet supplementation with synthetic antioxidants showed contradictive results. Thus, we tested, in this study, whether a daily dosage of Apple Cider Vinegar (ACV) would affect cardiovascular risk factor associated with obesity in high-fat diet (HFD)-induced hyperlipidemic Wistar rats. Obese rats showed increased serum total cholesterol, triglyceride, low-density lipoprotein-cholesterol (LDL-C), very low density lipoprotein (VLDL) and atherogenic index after 6 and 9 weeks of being fed an HFD. Importantly, ACV ameliorated all of these parameters significantly. Oxidative stress already developed after 6 weeks of HFD and was significantly reduced by daily doses of ACV. Oral administration of ACV normalized various biochemical and metabolic changes since it exhibited a very significant (P < .001) reduction in malondialdehyde levels, whereas an increase in thiol group concentrations and antioxidant status (superoxide dismutase [SOD], glutathione peroxidase [GPx], and catalase [CAT] activities and vitamin E concentrations). In addition, a modulation in trace element levels was observed when compared with HFD groups. These findings suggested that HFD alters the oxidant–antioxidant balance, as evidenced by a reduction in the antioxidant enzyme activities and vitamin E level, and enhanced lipid peroxidation. ACV can be beneficial for the suppression of obesity-induced oxidative stress in HFD rats through the modulating antioxidant defense system and reduces the risk of obesity-associated diseases by preventing the atherogenic risk.
A high-throughput microfluidic assay to study neurite response to growth factor gradients
Kothapalli, Chandrasekhar R.,van Veen, Ed,de Valence, Sarra,Chung, Seok,Zervantonakis, Ioannis K.,Gertler, Frank B.,Kamm, Roger D. Royal Society of Chemistry 2011 Lab on a chip Vol.11 No.3
<P>Studying neurite guidance by diffusible or substrate bound gradients is challenging with current techniques. In this study, we present the design, fabrication and utility of a microfluidic device to study neurite guidance under chemogradients. Experimental and computational studies demonstrated the establishment of a steep gradient of guidance cue within 30 min and stable for up to 48 h. The gradient was found to be insensitive to external perturbations such as media change and movement of device. The effects of netrin-1 (0.1–10 µg mL<SUP>−1</SUP>) and brain pulp (0.1 µL mL<SUP>−1</SUP>) were evaluated for their chemoattractive potential on neurite turning, while slit-2 (62.5 or 250 ng mL<SUP>−1</SUP>) was studied for its chemorepellant properties. Hippocampal or dorsal root ganglion (DRG) neurons were seeded into a micro-channel and packed onto the surface of a 3D collagen gel. Neurites grew into the matrix in three dimensions, and a gradient of guidance cue was created orthogonal to the direction of neurite growth to impact guidance. The average turning angle of each neurite was measured and averaged across multiple devices cultured under similar conditions to quantify the effect of guidance cue gradient. Significant positive turning towards gradient was measured in the presence of brain pulp and netrin-1 (1 µg mL<SUP>−1</SUP>), relative to control cultures which received no external guidance cue (<I>p</I> < 0.001). Netrin-1 released from transfected fibroblasts had the most positive turning effect of all the chemoattractive cues tested (<I>p</I> < 0.001). Slit-2 exhibited strong chemorepellant characteristics on both hippocampal and DRG neurite guidance at 250 ng mL<SUP>−1</SUP> concentration. Slit-2 also showed similar behavior on DRG neuron invasion into 3D collagen gel (<I>p</I> < 0.01 relative to control cultures). Taken together, the results suggest the utility of this microfluidic device to generate stable chemogradients for studying neurobiology, cell migration and proliferation, matrix remodeling and co-cultures with other cell lines, with potential applications in cancer biology, tissue engineering and regenerative medicine.</P> <P>Graphic Abstract</P><P>We describe a three-channel microfluidic device to study the role of chemogradients on neurite outgrowth and guidance in 3D scaffolds, using experimental and computational studies. The stable chemogradients in these devices could also be used to screen potential drugs for neuron pathway regeneration under disease/ injury conditions, cell migration and cell–cell interactions. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0lc00240b'> </P>