Relationship between Barcol hardness and flexural modulus degradation of composite sheets subjected to flexural fatigue

Raif Sakin 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.6

The aim of this study is to investigate the relationship between Barcol hardness (H) and flexural modulus (E) degradation of composite sheets subjected to flexural fatigue. The resin transfer molding (RTM) method was used to produce 3-mm-thick composite sheets with fiber volume fraction of 44%. The composite sheets were subjected to flexural fatigue tests and Barcol scale hardness measurements. After these tests, the stiffness and hardness degradations were investigated in the composite sheets that failed after around one million cycles (stage III). Flexural modulus degradation values were in the range of 0.41-0.42 with the corresponding measured hardness degradation values in the range of 0.25-0.32 for the all fatigued composite sheets. Thus, a 25% reduction in the initial hardness and a 41% reduction in the initial flexural modulus can be taken as the failure criteria. The results showed that a reasonably well-defined relationship between Barcol hardness and flexural modulus degradation in the distance range.

Marketing for Real and Virtual Museums: A Marketing Model to Explain Visitor Behavior in Real Museums and an Outlook on its Applicbility to Virtual Museurns

Raif Terlutter,Sandra Diehl 한국마케팅과학회 2002 마케팅과학연구 Vol.10 No.-

Layup Design Optimization for E-glass Woven Roving Fabric Reinforced Polyester Composite Laminates Produced by VARTM

Raif Sakin 한국섬유공학회 2021 Fibers and polymers Vol.22 No.2

In this study, a satisfactory number of actual test results were used to optimize the stacking sequence design ofbidirectional glass-woven fabrics in polyester composite laminates. In optimization, parameters such as glass-woven fabricswith five different areal weights, stacking sequence, number of plies (PLY), and off-axis fiber directions (DEG) were taken asinput factors. Values such as tensile strength (UTS) and flexural strength (UFS), mechanical anisotropy factors (AFs), andresin permeability coefficient of stacked glass-fabrics were taken as output responses. In this study, a laboratory-scalevacuum assisted resin transfer molding (VARTM) process was established. Composite laminates with sixteen differentstacking and six different number of plies are produced. Mechanical properties such as tensile and three-point flexure havebeen tested for the composite laminates obtained. In addition, the resin permeability coefficient for each laminate and the AFfor tensile and flexural module depending on fiber direction were calculated during production. Many actual test data wereobtained versus response to seven factors and five variables. Instead of the experimental designs recommended in responsesurface methodology (RSM), 64 actual test data were used as responses of the model. In the optimization with the Minitab,the minimum mechanical AF was desired in return to maximum UTS, UFS, and permeability coefficient. Optimum stackingsequence, PLY, DEG, permeability coefficient, and AFs were determined through using RSM. Consequently, the mostoptimal composite laminate was suggested in real terms in the desirability rate of laminate D=0.6731 with the stackingsequence of [822252]6, six plies, and 0 °/90 ° fiber direction.

The artificial intelligence revolution in dentistry: transformation in patient education

Raif Alan,Betül Melek Alan 대한치주과학회 2023 Journal of Periodontal & Implant Science Vol.53 No.6

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Peri-implant crevicular fluid levels of cathepsin-K, RANKL, and OPG around standard, short, and mini dental implants after prosthodontic loading

Raif Alan,İsmail Marakoğlu,Seyfullah Haliloğlu 대한치주과학회 2015 Journal of Periodontal & Implant Science Vol.45 No.5

Purpose: Despite the high success rates of endosseous dental implants, their placement is restricted according to the height and volume of bone available. The use of short or mini dental implants could be one way to overcome this limitation. Thus, this study aimed to compare standard, short, and mini dental implants with regard to associated clinical pa¬rameters and peri-implant crevicular fluid (PICF) levels of cathepsin-K (CTSK), RANK ligand (RANKL), and osteoprotegerin (OPG), after prosthodontic loading. Methods: A total of 78 non-submerged implants (Euroteknika, Aesthetica+2, Sallanches, France) were installed in 30 subjects (13 male, 17 female; range, 26–62 years) who visited the clinic of the Periodontology Department, Faculty of Dentistry, Selcuk University. Sam¬pling and measurements were performed on the loading date (baseline) and 2, 14, and 90 days after loading. Assessment of the peri-implant status for the implant sites was per¬formed using the pocket probing depth (PPD), modified plaque index, modified gingival in¬dex, modified sulcular bleeding index, and radiographic signs of bone loss. PICF samples collected from each implant were evaluated for CTSK, RANKL, and OPG levels using the ELISA method. Keratinized tissue and marginal bone loss (MBL) were also noted. Results: Clinical parameters statistically significantly increased in each group but did not show statistical differences between groups without PPD. Although implant groups showed a higher MBL in the upper jaw, only the standard dental group demonstrated a statistically significant difference. At 90 days, the OPG:sRANKL ratio and total amounts of CTSK for each group did not differ from baseline. Conclusions: Within the limitations of this study, both short and mini dental implants were achieving the same outcomes as the standard dental implants in the early period after loading.

Does the Modıfıed STING Method Increase the Success Rate in the Management of Moderate or Hıgh-Grade Reflux?

Osman Raif Karabacak,Fatih Yalçınkaya,Uğur Altuğ,Nurettin Sertçelik,Fuat Demirel 대한비뇨의학회 2014 Investigative and Clinical Urology Vol.55 No.9

Purpose: To evaluate the efficacy of subureteral injection types in patients with middletohigh-grade vesicoureteral reflux (VUR). Materials and Methods: Between June 1999 and September 2010, subureteral dextranomerwas applied at our clinic to 149 patients (214 refluxing ureters) with grades II,III, and IV VUR. Group 1 consisted of 54 patients (80 ureters), and group 2 consistedof 95 patients (134 ureters). The standard subureteric transurethral injection (STING)procedure was applied to group 1, and the modified STING procedure was applied togroup 2. A second and if needed a third injection was applied to unsuccessfully treatedpatients. The mean follow-up period was 2 years. Patients were evaluated by cystographyand ultrasonography in the third month of follow-up. Results: VUR was resolved completely after a single injection in 54/80 ureters (67.5%)in group 1 and in 94/134 ureters (70.1%) in group 2. Overall successes after a secondor a third injection were 61/80 (76.2%) and 111/134 (82.8%), respectively. There wasa statistically significant difference between the groups only for grade IV reflux followingmultiple injections (p<0.05). Conclusions: Endoscopic treatment of VUR is a recommended treatment because it isminimally invasive, efficient, and repeatable. Our study confirmed that a modifiedSTING procedure can be an alternative treatment to the standard technique.

Peri-implant crevicular fluid levels of cathepsin-K, RANKL, and OPG around standard, short, and mini dental implants after prosthodontic loading

Alan, Raif,Marakoglu, Ismail,Haliloglu, Seyfullah Korean Academy of Periodontology 2015 Journal of Periodontal & Implant Science Vol.45 No.5

Purpose: Despite the high success rates of endosseous dental implants, their placement is restricted according to the height and volume of bone available. The use of short or mini dental implants could be one way to overcome this limitation. Thus, this study aimed to compare standard, short, and mini dental implants with regard to associated clinical parameters and peri-implant crevicular fluid (PICF) levels of cathepsin-K (CTSK), RANK ligand (RANKL), and osteoprotegerin (OPG), after prosthodontic loading. Methods: A total of 78 non-submerged implants (Euroteknika, $Aesthetica^{+2}$, Sallanches, France) were installed in 30 subjects (13 male, 17 female; range, 26-62 years) who visited the clinic of the Periodontology Department, Faculty of Dentistry, Selcuk University. Sampling and measurements were performed on the loading date (baseline) and 2, 14, and 90 days after loading. Assessment of the peri-implant status for the implant sites was performed using the pocket probing depth (PPD), modified plaque index, modified gingival index, modified sulcular bleeding index, and radiographic signs of bone loss. PICF samples collected from each implant were evaluated for CTSK, RANKL, and OPG levels using the ELISA method. Keratinized tissue and marginal bone loss (MBL) were also noted. Results: Clinical parameters statistically significantly increased in each group but did not show statistical differences between groups without PPD. Although implant groups showed a higher MBL in the upper jaw, only the standard dental group demonstrated a statistically significant difference. At 90 days, the OPG:sRANKL ratio and total amounts of CTSK for each group did not differ from baseline. Conclusions: Within the limitations of this study, both short and mini dental implants were achieving the same outcomes as the standard dental implants in the early period after loading.

Development of a Mecanum-Wheeled Mobile Robot for Dynamic- and Static-Obstacle Avoidance Based on Laser Range Sensor

Musa Matli,Ahmet Albayrak,Raif Bayir 한국지능시스템학회 2020 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.20 No.3

This study aims to present an idea about the practical consequences of using mobile robots with Mecanum wheels. For mobile robots, an approach is proposed to avoid obstacles without location and map information. This approach is presented using a series of developed solutions. This article shares the process on how a set of discussed conceptual methodologies can be applied as well as their practical results. This method is provided using fuzzy logic and gap tracking. LIDAR is used to recognize obstacles around the mobile robot. By using the LIDAR, the robot detects gaps around it and moves according to fuzzy logic. The fuzzy logic consists of three inputs, an output, and 45 rules. The first of the membership functions represents the membership function that replaces the obstacle. The second membership function calculates the distance to the obstacle. The final login membership function is used to determine the angle between the obstacle and robot view. The output membership function represents the membership function that moves the robot. The results are analyzed under three different scenarios with five different experiments for each scenario. The results show that the mobile robot can avoid obstacles without location and map information. We believe that the proposed method can be used in mobile robots such as guard and service robots.

Wireless Sensor Networks with randomized parameters

Mikołaj Karpi?ski,Paweł Raif,Stanisław Rajba,Teresa Rajba,Vasyl Martsenyuk 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

In this paper we present a model of single-hop type wireless sensor network with random access and oneway transmission. In the paper, we analyze the WSN single-hop network using one single radio frequency, such that all nodes are divided into several groups depending on the average time between the transmissions. We replaced deterministic number of nodes in groups by random variables. We apply the Poisson Arrivals See Time Averages (PASTA) to modeling the WSN. We present the formula for the collision probability in the new model. The purpose of this approach is to match better the network model with random access to real world applications. In the paper we present an application of Wireless Sensor Network with random access and one-way transmission to monitoring hospital patients, such that all nodes are divided into several groups depending on the average time between the transmission due to the different state of health of patients.

Usefulness of In Vivo and In Vitro Diagnostic Tests in the Diagnosis of Hypersensitivity Reactions to Quinolones and in the Evaluation of Cross-Reactivity: A Comprehensive Study Including the Latest Quinolone Gemifloxacin

Semra Demir,Asli Gelincik,Nilgun Akdeniz,Esin Aktas-Cetin,Muge Olgac,Derya Unal,Belkis Ertek,Raif Coskun,Bahattin Colakoğlu,Gunnur Deniz,Suna Buyukozturk 대한천식알레르기학회 2017 Allergy, Asthma & Immunology Research Vol.9 No.4

Purpose: Reports evaluating diagnosis and cross reactivity of quinolone hypersensitivity have revealed contradictory results. Furthermore, there are no reports investigating the cross-reactivity between gemifloxacin (GFX) and the others. We aimed to detect the usefulness of diagnostic tests of hypersensitivity reactions to quinolones and to evaluate the cross reactivity between different quinolones including the latest quinolone GFX. Methods: We studied 54 patients (mean age 42.31±10.39 years; 47 female) with 57 hypersensitivity reactions due to different quinolones and 10 nonatopic quinolone tolerable control subjects. A detailed clinical history, skin test (ST), and single-blind placebo-controlled drug provocation test (SBPCDPT), as well as basophil activation test (BAT) and lymphocyte transformation test (LTT) were performed with the culprit and alternative quinolones including ciprofloxacin (CFX), moxifloxacin (MFX), levofloxacin (LFX), ofloxacin (OFX), and GFX. Results: The majority (75.9%) of the patients reported immediate type reactions to various quinolones. The most common culprit drug was CFX (52.6%) and the most common reaction type was urticaria (26.3%). A quarter of the patients (24.1%) reacted to SBPCDPTs, although their STs were negative; while false ST positivity was 3.5% and ST/SBPCDPTs concordance was only 1.8%. Both BAT and LTT were not found useful in quinolone hypersensitivity. Cross-reactivity was primarily observed between LFX and OFX (50.0%), whereas it was the least between MFX and the others, and in GFX hypersensitive patients the degree of cross-reactivity to the other quinolones was 16.7%. Conclusions: These results suggest that STs, BAT, and LTT are not supportive in the diagnosis of a hypersensitivity reaction to quinolone as well as in the prediction of cross-reactivity. Drug provocation tests (DPTs) are necessary to identify both culprit and alternative quinolones.