138 research outputs found
Multimode interference coupled ring cavity resonator with total internal reflection mirrors and semiconductor optical amplifier
The Effect of Remote Collaborative Work on Design Processes During the Pandemic
At the beginning of 2020, the virus called "COVID-19" spread rapidly all over the world. One of the measures taken to prevent the spread of the virus was social distance rules. Hence, employees and students had to work remotely using communication tools. In the design field, professionals and students working remotely during the pandemic, were limited to the possibilities of the communication tools they used while developing the design process, and they found ways to use these facilities in line with their practice routines in the physical environment. In this article, the tools used during the collaborative design processes conducted remotely during the pandemic were examined with a questionnaire study. Even though designers worked digitally due to the necessity to continue their work in this period, it was observed that they had positive experiences with the special tools they used. However, the transfer of tacit knowledge to design projects in the collaborative design process has been restricted in the collaborative design process due to limited spatial communication. While many designers were discovering the tailored tools for this purpose they could already use, many improvements were suggested through the unaware needs became explicit ones
Antimicrobial, anti-biofilm and cytotoxic properties of methallyl functionalized benzimidazolium-derived Ag(I)-Nheterocyclic carbene complexes
Purpose: To investigate the antimicrobial, antibiofilm, and cytotoxicity properties of methallyl substituted benzimidazolium-based, silver-bound N-heterocyclic carbene (Ag(I)-NHC) complexes, with respect to their potential to act as antimicrobial agents.Methods: The antimicrobial, antibiofilm, and cytotoxicity properties of the four complexes, the synthesis and characterization of which were carried out previously, were investigated. The antimicrobial properties were tested using the broth microdilution method, while their antibiofilm potential were determined by microtiter plate assay. The L-929 cell line was used for cytotoxic studies.Results: Strong antibiofilm and antimicrobial effects were produced by Ag(I)-NHC complexes. Compounds 2 and 3 showed potent activities against E. coli strain, with effects similar to that of positive control antibiotic, while compounds 1 and 4 exhibited antimicrobial activity at a concentration of 31.2 μg/mL. The compounds were effective against biofilms formed at concentrations in the range of 32 – 84 %, and degraded mature biofilms at a concentration range of 14 - 66 %. Compounds 1 and 2 did not significantly affect cell survival (p > 0.05), while compounds 3 and 4 significantly reduced cell survival, when compared with untreated cells in the control group (p < 0.001).Conclusion: This study may be one of the few studies on benzimidazolium-derived NHCs. The compounds which produced antimicrobial, antibiofilm, and cytotoxic properties in this study may be valuable and novel antimicrobial agents. Therefore, there is need for further in vivo and in vitro studies on these compounds
Simulation studies of spectral subtraction based temperature compensation of FBG sensor for structural health monitoring based on principal component analysis
Investigation of Antibacterial and Cytotoxic Properties of Mix Ligand Complex of Zinc 2-Fluorobenzoate with Nicotinamide
I n this study, antibacterial properties of the previously synthesized zinc 2-fluorobenzoate with nicotinamide complex at 1.17; 2.33; 4.67; 9.34 and 18.67 mM concentrations was investigated using by agar well diffusion method against Bacillus subtilis, Psedomonasa eruginosa, Staphylococcus aureus, Escherichia coli, Bacillus cereus and Klebsiella pneumoniae bacterias. The MTT method was used to determine the cytotoxic properties of the complex on human peripheral blood cells at the same concentrations. According to the results of the antibacterial study, it was determined that the complex showed a good antibacterial effect on all bacteria at 18.67 and 9.34 mM concentrations. The complex exhibits to have a suppressive effect only on S. aureus bacteria at a concentration of 2.33 mM. It was observed that the complex was antibacterial on all bacteria except B. cereus and E. coli at a concentration of 4.67 mM. The complex was found to have no growth inhibiting effect on any bacteria at a concentration of 1.17 mM. The cytotoxicity of the complex was investigated by MTT test method and it was determined that the cell viability decreased due to increasing concentration according to the test results. Cell viability at 1.17; 2.33; 4.67; 9.34 and 18.67 mM was determined to be 86.20%, 86.05%, 72.87%, 64.77% and 6.42%, respectivel
Effect of inner stiffeners on vibration and noise levels of gearbox housing without changing the mass
Especially, with the advancement of technology, mechanical parts need to be designed to be lighter and more durable. In the industry, gears are the most common power transmission equipment, and for this equipment, increasing durability and rigidity has an essential importance. During power transmission, undesired vibration and noise arise in gear systems. In addition to gear design, gearbox housing design is also essential to reduce the radiation of undesired structure-borne noise and vibration. In order to reduce noise and vibration levels, some modifications are frequently used on gearbox housings. In this study, three different gearbox housing designs (basic, cross and cellular) are formed and analysed by using ANSYS® software. The design alternatives for housings have been formed inside of the structure as different quantities of longitudinal and transverse stiffeners. In addition, all the external dimensions and the mass of these three housing designs are equal in order to observe just vibration and noise reduction. Fast Fourier Transform (FFT), statistical properties of vibration signals and sound levels of the gearbox have used for comparisons to determine which gearbox have better vibration and sound levels
Parameter Retrieval of Samples on a Substrate From Reflection-Only Waveguide Measurements
A microwave method has been proposed for constitutive parameters' extraction of samples on a known substrate. The advantage of this method is that it relies on noniterative reflection-only (air- and metal-backed) scattering (S-) parameters so that it is a good candidate for the characterization of samples when only one-port measurements are available. It is validated by the X-band (8.2-12.4 GHz) waveguide S-parameter measurements. A sensitivity analysis is followed to evaluate and improve the performance of our method. IEE
Preparation of Silicon-Antimony based Anode Materials for Lithium-Ion Batteries
I n this study, SixSb immiscible composite blend as anode materials have been synthesized using micron-sized silicone and antimony particles in different compositions through chemical reduction-mechanical alloying method CR-MA . The obtained microstructures have been investigated by X-ray diffraction XRD and Scanning Electron Microscopy SEM with Energy Dispersive X-Ray analysis EDX . Spectroscopic characterizations of the composite materials showed that a traditional intermetallic compound could not be achieved. However a novel immiscible composite blend system have been developed. One of the newly prepared composite materials, Si0.65Sb, exhibits an initial capacity of 790 mAh g-1 and a good cyclic stability compared to the pure silicone. The battery performance results of the micron-sized Si0.65Sb blend system have been compared with the commercially used graphite and the nano-sized Si/Sb alloy systems. The cycling stability of the micron-sized Si0.65Sb blend system showed an improvement compared to nano-sized Si/Sb alloy systems. Moreover its specific capacity is slightly higher than the commercial graphite anode material. These results portray the importance of micron sized Si/Sb system in large-scale applications due to its low cost
Corrigendum: Full-endoscopic removal of third ventricular colloid cysts: technique, results, and limitations
Full-endoscopic removal of third ventricular colloid cysts: technique, results, and limitations
IntroductionColloid cysts (CCs) are rare benign lesions that usually arise from the roof of the third ventricle. They may present with obstructive hydrocephalus and cause sudden death. Treatment options include ventriculoperitoneal shunting, cyst aspiration, and cyst resection microscopically or endoscopically. This study aims to report and discuss the full-endoscopic technique for removing colloid cysts.Materials and methodsA 25°-angled neuroendoscope with an internal working channel diameter of 3.1 mm and a length of 122 mm is used. The authors described the technique of resecting a colloid cyst by a full-endoscopic procedure and evaluated the surgical, clinical, and radiological results.ResultsTwenty-one consecutive patients underwent an operation with a transfrontal full-endoscopic approach. The swiveling technique (grasping the cyst wall and rotational movements) was used for CC resection. Of these patients, 11 were female, and ten were male (mean age, 41 years). The most frequent initial symptom was a headache. The mean cyst diameter was 13.9 mm. Thirteen patients had hydrocephalus at admission, and one needed shunting after cyst resection. Seventeen patients (81%) underwent total resection; 3 (14%), subtotal resection; and 1 (5%), partial resection. There was no mortality; one patient had permanent hemiplegia, and one had meningitis. The mean follow-up period was 14 months.ConclusionEven though microscopic resection of cysts has been widely used as a gold standard, successful endoscopic removal has been described recently with lower complication rates. Applying angled endoscopy with different techniques is essential for total resection. Our study is the first case series to show the outcomes of the swiveling technique with low recurrence and complication rates
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