Primjena metode konačnih elemenata za modeliranje drvno-plastičnih kompozita ojačanih vlaknima za uporabu u konstrukciji namještaja s polukrutim vezovi

In this study, control samples of pine (Pinus slyvestris L.), beech (Fagus orientalis L.) and oak (Quercus petreae L.) species were obtained by using fi ber reinforced finger corner joints. Teknobont 200 epoxy and polyvinyl (PVAc) adhesives were used as glue. Bearing in mind the critical loads that may affect their use, experimental samples were tested under diagonal loads. Experimental samples were also analyzed by a computer program using the finite element method (FEM). Finally, experimental data were compared with the results of FEM. The comparisons clearly showed that experimental results and finite element solutions (SAP2000 V17) including semi-rigid connections are in good agreement. As a structural analysis program in furniture engineering designs, FEM can be preferred in terms of reliability and cost.U radu se prikazuju rezultati istraživanja uzoraka borovine (Pinus slyvestris L.), bukovine (Fagus orientalis L.) i hrastovine (Quercus petreae L.) spojenih kutnim zupčastim spojevima i ojačanih vlaknima. Kao ljepilo upotrijebljeno je epoksidno ljepilo Teknobont 200 i polivinilacetatno ljepilo (PVAc). Imajući na umu opterećenja koja se pojavljuju tijekom uporabe, eksperimentalni su uzorci ispitivani pri dijagonalnim opterećenjima. Uzorci su također analizirani računalnim programom primjenom metode konačnih elemenata (FEM). Eksperimentalni podatci i podatci dobiveni FEM analizom uspoređeni su te se jasno može vidjeti da se ti podatci za polukrute vezove podudaraju. Glede pouzdanosti i troškova, kao strukturnom programu analize u dizajniranju namještaja prednost se može dati FEM analizi

Analiza kompozita od kopolimera stirena i anhidrida maleinske kiseline (SMA) punjenih pregrijanim drvom metodom konačnih elemenata

The computer aided three dimensional static analyses of the specimens was done by using the Finite Element Method (FEM) and obtained data was compared with actual test data. The aim of this study is to compare the deformation/stress analyses with FEM analysis results of styrene maleic anhydride (SMA) copolymer composites. The heat treated wood/SMA copolymer composites were produced from different loadings (from 10 to 30 wt. %) of heat treated and untreated eastern white pine wood flours (Pinus strobus L.). All formulations of wood flour/SMA copolymer composites were produced by melt compounding through injection molding. The deformation/stress results obtained from the experimental solutions are very close to the results obtained from the numerical solutions (SAP2000 V17). As a result, it can be said that it is beneficial to use the FEM in the engineering design approach after the data obtained by the experimental solutions as meaningful values after application of the FEM.Računalom potpomognuta trodimenzionalna statička analiza uzoraka provedena je metodom konačnih elemenata (FEM). Dobiveni su podatci uspoređeni sa stvarnim ispitnim podatcima. Cilj rada bio je usporediti analizu deformacija/naprezanja s rezultatima FEM analize kompozita od kopolimera stirena i anhidrida maleinske kiseline (SMA). Kompoziti od pregrijanog drva i SMA kopolimera bili su izrađeni s različitim udjelom (od 10 do 30 % težine) drvnog brašna od pregrijanoga i nepregrijanog drva američkog borovca (Pinus strobus L.). Sve formulacije kompozita od drvnog brašna i SMA kopolimera bile su izrađene injekcijskim prešanjem. Rezultati deformacija i naprezanja dobiveni eksperimentalno vrlo su slični rezultatima dobivenim računskim putem (SAP200 V17). Može se zaključiti da je analiza metodom konačnih elementa, kombinirana s eksperimentalno dobivenim podatcima, korisna u inženjerskom projektiranju

Adult posterior urethral valve: a case report

Introduction: Posterior urethral valve (PUV) is a congenital obstructive defect of the male urethra with an incidence of 1/8,000 to 1/25,000 live births. PUV is the most common cause of lower urinary tract obstruction in neonates. The diagnosis of PUV is usually made early, and PUV cases have rarely been detected in adults

Retroperitoneal Lymph Node Mapping with Patent Blue Dye Injection: Is the Testicular Route Feasible?

[Arch Clin Exp Surg 2012; 1(2.000): 125-126

Diagnostic value of free-to-total PSA proportion and PSA density in prostate cancer detection for prostate volumes >= 100 cc

Introduction: Free to total PSA proportion (f/t FPSA) and PSA density (PSAD) are mostly used PSA derivatives for better cancer detection. In this study, we aimed to evaluate whether or not f/t PSA and PSAD had any diagnostic contribution to prostate cancer (pCa) detection in patients that had prostate volumes >= 100 cc. Material and Methods: The medical records of transrectal ultrasound guided prostate biopsy performed patients were retrospectively evaluated and divided into two categories according to their prostate volumes (=100 cc). The diagnostic value of total PSA, PSAD and f/t PSA in prostate cancer detection for prostate volumes >= 100 cc were statistically evaluated. Results: Among 311 patients 51 and 260 had prostate volumes >=100 cc and =100 cc. Although larger and prospective studies are warranted to make better inferences, up to that time our results may guide clinicians in their daily practice. [Arch Clin Exp Surg 2018; 7(4.000): 166-170

Robotic and laparoscopic urologic surgery ischemic preconditioning

Laparoscopic and robotic assisted surgeries have evolved from a limited surgical procedure to a major surgical technique during the last three decades. The indications increased incrementally. Despite its several advantages, it has some surgery and pneumoperitoneum related adverse effects and hemodynamic complications. One of them is the ischemia reperfusion injury (IRI) of the abdominal organs that can be developed secondary to pneumoperitoneum. IRI is also a risk factor for acute kidney injury in partial nephrectomy surgeries even performed via open, or laparoscopic/robotic assisted. To reduce or avoid the IRI related complications during laparoscopy and robotics, several alternative approaches were suggested including ischemic preconditioning (IPC). IPC is a phenomenon that promotes tissue tolerance to ischemia. Since it was first introduced, several studies evaluating its protective effects or mechanism of action have been published. Majority of them demonstrated its potent beneficial effects against IRI. Despite these favorable results, IPC has not yet been used in clinical settings routinely. The unknown parts of the exact mechanisms, the lack of standard protocols for its use such as the duration of clamping, the number of clamping cycles, using an early window or a late window, using local IP or remote IP, and the all remaining uncertainly about these aspects of the process might lead clinicians to be hesitant about its clinical use. In this study we discussed what we have in our hands regarding the effects of IRI and protective mechanisms of IPC, animal studies and clinical evidence of IPC, remote and local IPC, laparoscopy/robotics induced IRI, and role of laparoscopic/robotic IPC

Assessment of In Vitro Antigenotoxic Effect of Nigella Sativa Oil

Objectives: Cyclophosphamide (CP) is an alkylating agent widely used as an antineoplastic and immunosuppressive agent. The genotoxicity of CP has been studied in a variety of in vivo and in vitro systems and is routinely used as a positive control in genotoxicity tests. Traditional medicine Nigella sativa L., (N. sativa), Ranunculaceae family, especially in the Eastern Mediterranean countries, especially in many countries, and is widely used in many countries as a spice and folk medicine since the time of Dioscorides used as a plant. In this study, it was aimed to show the protective effects of N. sativa oil at different concentrations against the genotoxic effects of CP by micronucleus test. Materials and Methods: For this purpose, healthy cells were treated in vitro with N. sativa oil at concentrations of 1, 5, 10 mu g/mL and CP as positive control for 68 hours. The micronuclei were then counted. Results: No significant increase in micronucleus frequency was observed when the application of N. sativa oil at concentrations of 1, 5. 10 mu g/mL compared with the negative control. There was a decrease in the number of micronucleus in all three concentrations (1, 5, 10 mu g/mL) compared to the CP group in the groups treated with N. sativa oil and CP. Conclusion: It has been shown that N. sativa oil may have protective effects against genotoxicity agents in vitro. But more work is needed to understand the mechanism of the genotoxicity effects of N. sativa oil