Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Alkan, Elif(6)
- Sipahi, Ferkan(6)
- Turan, Ibrahim(6)
- Akkan, Yaşar(5)
- Atar, Musa(5)
- Bostan, Sedat(5)
- Demir, Selim(5)
- Akaryali, Enver(4)
- Aksakal, Vecihi(4)
- Aliyazicioglu, Yuksel(4)
- Ates, Nagihan Gozde(4)
- Fidan, M. Said(4)
- Gergerli, Ruken(4)
- Kaygusuz, Abdullah(4)
- Okan, Tarhan(4)
- Tulgar, Serkan(4)
- Yilmaz, Fetullah(4)
- Akyüz, Ahmet Mutlu(3)
- Alwasel, Saleh H.(3)
- Arslan, Mehmet(3)
- Ashyralyev, A.(3)
- Aydınçakır, Emre(3)
- Aşık, Yusuf(3)
- Baltaci, Cemalettin(3)
- Bayraktar, Alemdar(3)
- Bayram, Bahri(3)
- Demir, S.(3)
- Dincel, Gungor Cagdas(3)
- Gocer, Hulya(3)
- Gökhan, Nezihe(3)
- Güllüpunar, Hasan(3)
- Gülçin, Ilhami(3)
- Günaydin, Murat(3)
- Kaplan, Abdullah(3)
- Karakan, Mehmet(3)
- Karakilic, Evvah(3)
- Küçük, Murat(3)
- Lukashov, A.(3)
- Merdan, Kurtuluş(3)
- Nazir, Bayram(3)
Yayınlar
- MakaleAçık Erişim2016Stability assessment of high-steep cut slope debris on a landslide (Gumushane, NE Turkey)
Kaya, Ayberk; Alemdağ, Selçuk; Dağ, Serhat; Gürocak, Zülfü
The objective of this study was to examine the effects on the stability of slope debris of planned slope excavations around the vicinity of Gumushane Imam-Hatip High School in NE Turkey. To assess the geotechnical properties of slope debris along the determined cross-sections, four exploration boreholes with a total length of 100 m were drilled and undisturbed soil samples were collected. Slope debris is composed of two soil zones and its depth varies between 15 m and 21 m. It was determined from the experimental results that the soil class of the upper zone is CL (low plasticity clay) and CH (high plasticity clay) whereas the soil class of the lower zone is SC (clayey sand) and GC (clayey gravel). Peak cohesions of the upper and lower zones were 26.3 kPa and 10.2 kPa, and their peak internal friction angles were 16° and 24°, respectively. Limit equilibrium (LE) analyses for the slopes were evaluated using Slide v5.0 software for the pre-excavation, post-excavation, and supported cases. The results of LE analyses showed the existence of a landslide along the SW direction; the landslide would extend to cover the whole region if the excavation were to be performed without applying engineering measures. Finally, the precautions to be taken were determined and stability analyses for the supported case were evaluated. These analyses showed that the active lateral forces applied by the proposed retaining walls to the cut slope should be 8325 and 3103 kN, respectively.
- MakaleYalnız künye2016Lipstick politics and framing competition: an experiment about the Turkish Airlines news
Özarslan, Hüseyin; Güran, Mehmet Salih
ABSTRACT: Framing is a discourse forming procedure with a direct effect on the very meaning of the news coverage. While framing itself is unavoidable, its controlled usage requires not only individual journalistic awareness of cultural, social, ideological and even psychological factors, but it also requires an institutionalization and cultivation of journalistic best practice. This experiment studies the effects of different news framing practices of the same event on audience reception by using actual news coverage from the Turkish media. 348 students were randomly assigned to three experiment groups where they were exposed to actual news stories about a corporate attire regulation at the Turkish Airlines that had been recently issued. A factor analysis explored their thoughts on the news stories and produced respectively the managerial requirements frame and the repression of women frame as most apparent in the thoughts of the participants of the respective groups.
- MakaleYalnız künye2016A New Approach for Determination of Volumetric Water Content in Soil Samples by Gamma-Ray Transmission
Celik, Necati; Altin, Duygu; Cevik, Ugur
A new method was presented for the purpose of volumetric water content determination in any soil sample by gamma-ray transmission. Monte Carlo (MC) simulation technique was used to determine the functional behavior of the linear attenuation coefficient of soil samples having different water contents for three soil samples. Using this functional behavior, the linear attenuation coefficients of dry soil and water were obtained from the intercept and the slope, respectively. It was experimentally shown that the mass attenuation coefficients of soil samples were not sensitive to the chemical composition but only to the physical density. This independence was exploited in this study to obtain the linear attenuation coefficient of a completely dry soil which was found to be 0.1409, 0.1274, and 0.1657 cm−1 for Gumushane, Ardahan, and Trabzon soil, respectively. The linear attenuation coefficient of water was determined to be 0.09 cm−1. Then, the volumetric water contents were obtained by measuring the gamma-ray intensities passed through three wet soil samples. The results were found to be 0.186, 0.182, and 0.214 cm3 cm−3 for Gumushane, Ardahan, and Trabzon soil, respectively. The results obtained by the method introduced were compared with the results obtained using gravimetric method. A very good agreement was observed.
- MakaleYalnız künye2016Effects of organic solid cattle manure application on nutritive value of winter cereal forages
Yolcu, H.; Gullap, M.K.; Yildirim, M.; Lithourgidis, A.; Deveci, M.
Nutritive value of winter cereal forages is one of interested subjects of farmers for animal feeding. Field experiments were established in 2007–2008 and 2008–2009 growing seasons in northeast Turkey to investigate the effect of organic solid cattle manure application (0, 10 and 20 Mg ha−1 yr−1) on nutritive value of three annual cereals for forage. The winter cereal forages were: wheat (Triticum aestivum L.), oat (Avena sativa L.) and rye (Secela cereale L.). ADF (acid detergent fiber), NDF (neutral detergent fiber) CP (crude protein), nitrogen, phosphorus, potassium, sulfur, calcium, copper, iron, magnesium, manganese, sodium, zinc and boron (N, P, K, S, Ca, Cu, Fe, Mg, Mn, Na, Zn and B) concentrations were researched in this study. Wheat had the highest CP, N, Ca, Cu, Na and Zn concentration, whereas oat had the lowest ADF and NDF and the highest K, Fe and Mn concentrations. The greatest Mg and P concentrations were determined in rye. Organic solid cattle manure applications had no effect on N and CP contents, but it decreased ADF and NDF contents. However, in most cases it positively affected the P, B, Cu, Fe, Mg and Na concentrations, whereas it decreased K, Ca, Mn and Zn concentrations. The results showed that wheat and oat are more nutritive species than rye in terms of animal feeding and the organic solid cattle manure, in some cases increased the nutritive values of wheat, oat and rye under organic agriculture conditions.
- MakaleYayıncıda açık erişim2016Effects of non-uniform temperature distribution on critical member temperature of steel tubular truss
Ozyurt, E.; Wang, Y.C.
This paper examines the effects of thermal restraint, caused by non-uniform temperature distribution in different members, on the failure temperatures of critical members of steel tubular trusses. Non-uniform temperature distribution develops in trusses exposed to localised fire attack. The truss member nearest to the fire source experiences the highest temperature, with reduced temperatures in the nearby members. The number of the nearby truss members being heated and their temperatures will affect the failure temperature of the critical truss member which has the highest temperature. The aim of this paper is to develop a simplified method to account for the effects of different numbers of members being simultaneously heated to different temperatures on the development of compression force and failure temperature of the critical member. Finite Element (FE) simulations were carried out for Circular Hollow Section (CHS) trusses using the commercial Finite Element software ABAQUS v6.10-1 which has previously been validated by the authors. The simulation trusses were subjected to constant mechanical loads and then increasing temperatures until failure. The elevated temperature stress-strain curves were based on EN-1993-1-2 [1]. Initial geometrical imperfections were included, based on the lowest buckling mode from eigenvalue analysis.The numerical study examined the effects of truss type, critical member slenderness, applied load ratio and axial restraint stiffness ratio on the failure temperatures of the critical truss members. The numerical simulation results were used to check the accuracy of a proposed simplified calculation method, combining linear elastic static truss analysis at ambient temperature and analytical equations to calculated the failure temperatures of thermally restrained truss members based on the regression equations of Wang et al. [2]. The calculation method was shown to be sufficiently accurate for fire resistant design purpose.
- MakaleAçık Erişim2016Increased expressions of eNOS and iNOS correlate with apoptosis of diabetic nephropathy in streptozotocin-induced type 1 diabetic rats; [Streptozotosin kaynaklı tip 1 diyabetik sıçanlarda meydana gelen nefropatilerde artan eNOS ve iNOS sunumlarının apoptozisle ilişkilendirilmesi]
Dinçel, Güngör Çağdaş; Yildirim, Serkan
The present study was designed to evaluate the effects of high level of nitric oxide (NO) production and oxidative stress (OS) on nephropathology and to identify whether NO and OS have any correlation with apoptosis seen in diabetic kidney, elucidating the underlying mechanism(s) involved in the development of nephropathology in streptozotocin (STZ)-induced diabetic rats. Expression levels of caspase 3, caspase 9, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), 8-hydroxy-2′-deoxyguanosine (8-OHdG), for the detection of oxidative damage to DNA, were examined in diabetic kidney tissues. Results of the study revealed that the levels of 8-OHdG (P<0.005), eNOS (P<0.005), iNOS (P<0.005), caspase 3 (P<0.005) and caspase 9 (P<0.005) were remarkably higher in diabetic kidney tissues than in controls. In addition, STZ-treated animals showed significant loss of body weight and renal enlargement. It was suggested that apoptosis, OS and increased NO levels are involved in the pathogenesis of diabetic nephropathy. The results also strongly suggested that STZ-induced apoptosis through activation of the intrinsic pathway and that might be most likely related to increased NO levels. Moreover, high NO production was not only mediated by eNOS but also by iNOS. Increased NO production may contribute to hyperfiltration and microalbuminuria in early diabetic nephropathy. Furthermore, expression of 8-OHdG might give an idea of the progress and may be essential as it has a diagnostic significance for this disease. In conclusion, we believe that eNOS and iNOS overexpressions induce diabetic nephropathy by mediating apoptosis in STZ-induced rats.
- MakaleYalnız künye2016A semiautomatic segmentation approach to biometric measurement of the talus bone of sedentary women and ballerinas using CT images
Reis, Hatice Catal; Bayram, Bulent; Seker, Dursun Zafer
Background: Ballet produces much stress on bones in the feet of ballerinas. Monitoring and detecting talus bone deformation is important for their quality of health and profession. Objectives: To determine differences in the talus bone between ballerinas and sedentary women. Methods: We evaluated biometric differences in the talus bone of 5 ballerinas referenced to 5 similar sedentary women recruited into the present study. We acquired 20 multidetector computed tomographic images including right and left feet. Semiautomatic region-based image processing using 3D-Doctor (Able Software Corp) was used to create three-dimensional (3D) virtual models of the talus bones. Biometric measurements were made on the 3D models and statistical analysis conducted. Results: The mean talus bone length of ballerinas was 3.37 cm (SD 0.12; range 3.11 to 3.52). The talus bone length of sedentary women was 3.29 cm (SD 0.16; range 3.04 to 3.65), and tended to be shorter than that of the ballerinas (P = 0.08, t test). However, the test was insufficiently powered. The mean volume of the talus bones from the ballerinas was 24.8 cm3 (SD 0.83) and smaller than that from the sedentary women, 26.9 cm3 (SD 1.25) at P < 0.001 (t = 4.38, 18 degrees of freedom. Difference 2.1. Two-tailed 95% confidence interval for difference of means: 1.08 to 3.08). We found less variation in the feet of ballerinas than sedentary women. Conclusions: Volumetric measurements show that feet of ballerinas are smaller and retain similar shape and size than the irregular feet of sedentary women.
- MakaleAçık Erişim2016Effects of Origanum syriacum essential oil added in different levels to the diet of broilers under heat stress on performance and intestinal histology; [Einfluss des zusatzes der essentiellen Öle von origanum syriacum in unterschiedlicher höhe zum futter auf die leistung und die darmmorphologie von broilern unter hitzestress]
Tekce, E.; Gül, M.
This study compared the effects on performance parameters, intestinal microflora and histology of adding Origanum syriacum (OS) essential oil and an antibiotic (Avilamycin) to the rations of broilers fed under heat stress conditions. The 42-day study used 500 day-old male broilers (Ross-308) divided into 10 groups of 50 animals each. Then, each of these groups was further divided into 5 groups of 10 each. Groups were either kept at 22°C (stress-free) or at 36°C (heat stressed). Birds were fed with 5 experimental diets: control (basic feed (BF) without feed additive), antibiotic (BF + 100 mg/kg Avilamycin), OS 100 (BF + 100 mg/kg OS), OS 300 (BF + 300 mg/kg OS, OS 600 (BF + 600 mg/kg OS). At the end of the study period, some performance parameters, including feed intake, feed-conversion ratio, body weight, average daily weight gain, ileum crypt depth, villus height and microflora, decreased in groups under heat stress without additives (P < 0.01). However, comparison with the control group and the antibiotic group showed that adding OS essential oil provided a benefit close to that of the antibiotic, yet still inadequate, even at the 600 mg/kg dose.
- MakaleAçık Erişim2016Physicochemical and bioactive properties of cakes incorporated with gilaburu fruit (Viburnum opulus) pomace
Şeker, I.T.; Ertop, M.H.; Hayta, M.
In this study the valorisation of a gilaburu (Viburnum opulus) fruit pomace, a waste product remaining after juice extraction, was investigated. The pomace was incorporated into cake formulation at the level of 0, 5, 10 and 15%, based on wheat flour weight. Results indicated that the batter viscosity increased and pH decreased by the increasing of the concentration of pomace level in cake formulation. Depending on incorporation level, reduction on the volume and height of the cake samples were observed. The hardness values increased whereas the chewiness and gumminess values of the cake samples decreased with an increasing of pomace incorporation level. Gilaburu pomace addition caused significant (P<0.05) changes on L*, a*, and b* values of crumb, whereas no significant differences have been determined on the L* and b* values of crust of the samples. In sensory analyses, 5% gilaburu pomace added cake sample had the highest overall acceptability score. The total phenolic content and radical-scavenging activity values of cake samples increased proportionally with the level of pomace incorporation. According to the study, evaluation of gilaburu pomace waste as ingredient in developing alternative functional and/or value-added products by the food industry could be suggested.
- MakaleYalnız künye2016Selective cytotoxic effect of Rhododendron luteum extract on human colon and liver cancer cells
Demir, Selim; Turan, Ibrahim; Aliyazicioglu, Yuksel
Purpose: The genus Rhododendron is distributed entirely in the world with the exception of South and Central America and Africa, growing in a large diversity of climatic conditions. This genus is a rich source of phenolic compounds, especially flavonoids, essential oils, chromones, terpenoids, and steroids. It has many biological properties such as antioxidant, anti-inflammatory, antiviral, antibacterial, anticancer, antidiabetic, immunomodulatory, cardioprotective and hepatoprotective among others due to their polyphenolic constituents. The objective of the current study was to evaluate the antioxidant properties and cytotoxic activity of dimethyl sulfoxide extract of flowers of Rhododendron luteum (DEFR) for the first time. Methods: The total polyphenolic contents (TPC), total flavonoid contents (TFC) and ferric reducing antioxidant power (FRAP) of the extract were evaluated using spectrophotometry procedures. The cytotoxic activity of the extract on three cancers (human breast, colon and liver carcinoma) and human foreskin fibroblast cells was determined using the MTT assay. Results: TPC and FRAP values were found 54.2+.0.38 mg gallic acid equivalents and 164.2±1.77 mg trolox equivalents per to g sample, respectively. R. luteum extract exhibited selective cytotoxicity against colon and liver cancer cells compared to normal fibroblast cells, while this selective cytotoxicity was not observed in breast cancer cells. Conclusion: Our results demonstrate that the Rhododendron luteum may be a great source of antioxidant and antitumor natural agents due to their capability of decreasing cancer cells proliferation.
- MakaleAçık Erişim2016Role of oxidative stress in the pathophysiology of Toxoplasma gondii infection
Dincel, Gungor Cagdas; Atmaca, Hasan Tarik
Oxidative stress (OS) plays an essential role in the pathogenesis of common neurodegenerative diseases. We have previously shown that Toxoplasma gondii (T. gondii) induces high nitric oxide (NO) production, glial activation, and apoptosis that altogether cause severe neuropathology in toxoplasma encephalitis (TE). The objective of this study was to investigate the cytotoxic effect of OS and to identify a correlation between the causes of T. gondii induced neuropathology. Expression levels of glutathione reductase (GR), Cu/Zn superoxide dismutase (SOD1), neuron specific enolase (NSE), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were investigated. Results of the study revealed that the levels of GR (P <0.005) and NSE (P <0.001) expression in the brain tissue markedly increased while SOD1 activity decreased (P <0.001) in the infected group compared to the non-infected group. In addition, intense staining for 8-OHdG (P <0.05) was observed both in the nucleus and the cytoplasm of neurons and glial cells that underwent OS. These results were reasonable to suggest that T. gondii-mediated OS might play a pivotal role and a different type of role in the mechanism of neurodegeneration/neuropathology in the process of TE. The results also clearly indicated that increased levels of NO and apoptosis might contribute to OS-related pathogenesis of TE. As a result, OS and expression of NSE might give an idea of the disease progress and may have a critical diagnostic significance for patients with T. gondii infection.
- MakaleYalnız künye2016Systemic oxidant/antioxidant balance in human abdominal aortic aneurysm
Menteşe, Umit; Turan, Ibrahim; Usta, Sefer; Demir, Selim; Koral, Özgür; Öztaş Menteşe, Seda; Çavuşoǧlu, Ismail Gökhan; Karahan, Süleyman Caner; Alver, Ahmet; Doǧan, Orhan Veli
The aim of this study was to evaluate the oxidant-antioxidant balance in patients with abdominal aortic aneurysms (AAA). Forty-two consecutive patients with AAA and 46 control subjects were included. Total oxidant status (TOS) and total antioxidant status (TAS) levels were measured and the oxidative stress index (OSI) value determined. Serum TOS and OSI values in patients with AAA were higher than those in the controls (p<0.001, p<0.001, respectively). There was a positive correlation between abdominal aortic diameters, serum TOS levels (r=0.592, p<0.001) and OSI values (r=0.598, p<0.001). A cut-off value of 17.68 μmol H2O2 equivalent/L for TOS was associated with 86% sensitivity and 83% specificity and a cut-off value of 1.77 for OSI was associated with 86% sensitivity and 81% specificity for predicting AAA. Systemic oxidative imbalance develops in patients with AAA, particularly as a result of an increase in TOS.
- MakaleAçık Erişim2016Investigation of the inhibitory properties of some phenolic standards and bee products against human carbonic anhydrase I and II
Aygul, Imdat; Yaylaci Karahalil, Fatma; Supuran, Claudiu T.
Polyphenols are important secondary products of plants with the potential to inhibit carbonic anhydrases. The aim of this study was to investigate the inhibition effects of various phenolic standards, honey, propolis, and pollen species on human carbonic anhydrase I and II. The inhibition values (IC50) of the phenolics (gallic acid, protocatechuic acid, quercetin, catechin, tannic acid, and chrysin) ranged from 0.009 to 0.32 μg/mL, tannic acid emerging as the best inhibitor. The inhibition values of three different types of honey, heather, rhododendron, and chestnut ranged between 2.32 and 25.10 μg/mL, the chestnut honeys exhibiting the best inhibition. The ethanolic extracts of pollen and propolis exhibited good inhibitory properties, with IC50 values between 0.486 and 3.320 μg/mL. In order to evaluate the phenolic composition of bee products, phenolic profiles and total phenolic contents (TFC) were also measured. The inhibition ranking among the natural products studied was phenolic standards > propolis > pollen > honeys, and inhibition was related to TFC.
- MakaleYayıncıda açık erişim2016The effects of Co addition on the mechanical and microstructural properties of the matrix material of a Fe-based marble cutting tool
Budak, S.; Kaplan, M.
In this study, four different kinds of marble cutting matrices with a base composition of Fe-Cu-Sn and with variable amounts of Co powder were produced. For compaction, hot sintering process was carried out at 850°C under 35 MPa for 4 min. The mechanical and microstructural properties of the matrix materials were determined using SEM with EDS, three-point bending test, density and hardness measurement techniques. The addition of Co powders to the matrix and the subsequent hot sintering process affected the mechanical and microstructural properties of the cutting tool, such as hardness, total elongation, % porosity and phase distribution.
- MakaleYalnız künye2016Effect of seasonal changes on the combustion characteristics of impregnated cedar (Cedrus libani A. Rich.) wood
Fidan, M. Said; Yaşar, Ş. Şadiye; Yaşar, Mehmet; Atar, Musa; Alkan, Elif
Wood is an irreplaceable material used as decorative and structural element both indoors and outdoors. When used as a structural material, wood has several superior characteristics in comparison to other structural constituents, although it is adversely affected by fires as well as biotic pests and abiotic effects. In this study, cedar (Cedrus libani A. Rich.) wood samples were impregnated using either Tanalith-E or Wolmanit-CB as detailed in ASTM-D 1413-76 and surface-treated using water-based or synthetic varnish. The impregnated and varnished samples were left outdoors with the aim of investigating the effect of seasonal changes. The samples were later subjected to combustion analysis as detailed in the combustion test standard ASTM-E 160-50. The results of the study indicated that the weight loss was lower during winter (87.82%), for samples that were impregnated using Wolmanit-CB (88.90%) and those that were treated with synthetic varnish (88.45%). On the other hand the O2 and CO2 contents were determined to be the highest in fall during combustion without flame (18.16% and 17.96%, respectively); the CO content was the highest during combustion without flame for the winter samples (28,907 ppm) and the NO content was the highest during combustion without flame for the spring samples (76.15 ppm). In conclusion, the winter samples that were impregnated using Wolmanit-CB and treated with synthetic varnish were determined to be safer to employ in areas with high fire risk.
- MakaleYayıncıda açık erişim2016Organic geochemistry and element distribution in coals formed in eocene lagoon facies from the Eastern Black Sea Region,NE Turkey
Saydam Eker, Çiğdem; Akpinar, İbrahim; Sipahi, Ferkan
The amount and type,the inorganic element content,and the maturity of organic materials of Eocene coals,shaly coals,and coaly shales exposed in the Gümüşhane and Bayburt districts of the Eastern Black Sea Region of Turkey were investigated. The depositional environments and hydrocarbon potentials were also interpreted. The total organic carbon concentrations in the studied samples ranged from 0.50% to 63.08%. The samples from Özyurt,Kayadibi,and Tarhanas contained types II and III kerogen,and those from Sökmen and Manas contained type III kerogen. The samples contained Co,Cs,Ga,Hf,Th,U,Y,Mo,Be,Cd,Sb,and La,with average values similar to those of standard brown coals. The samples showed average contents of Co,Ga,Nb,Rb,V,Y,Cu,Pb,Zn,As,Be,and Se,similar to those of other Turkish coals. The sediment source of Eocene samples in the five areas was characterized by rocks with intermediate or mafic geochemical characteristics. The terrigenous/aquatic ratio of coal and shaly coal samples of the areas in question is >1. The sterane distribution was C29 > C28 > C27 and C29 > C27 > C28 for the Özyurt and Tarhanas areas,respectively. The average Tmax values for samples are between 424 °C and 460 °C. For samples Oz-1 and Ta-2,22S/(22S + 22R) homohopane (C32) ratios are 0.48 and 0.61,respectively; 20S/(20S + 20R) sterane (C29) ratios are 0.18 and 0.53,respectively; and Ts/(Ts + Tm) ratios are 0.015 and 0.64,respectively. The Pr/Ph ratios of the samples are >3. The studied samples have low sterane/hopane and high (C19+C20)/C23) ratios without anoxic biomarkers (17α(H)-28,30-bisnorhopane). Based on these data,the coals,shaly coals,and coaly shales were probably deposited under an oxic-suboxic mixture of marine and terrestrial environment conditions; these materials contain terrestrial organic matter and cannot generate hydrocarbon.
- MakaleAçık Erişim2016Optimum Tuning of a Gyroscopic Vibration Absorber Using Coupled Gyroscopes for Vibration Control of a Vertical Cantilever Beam
Ünker, F.; Çuvalci, O.
This paper deals with the investigation of optimum values of the stiffness and damping which connect two gyroscopic systems formed by two rotors mounted in gimbal assuming negligible masses for the spring, damper, and gimbal support. These coupled gyroscopes use two gyroscopic flywheels, spinning in opposing directions to have reverse precessions to eliminate the forces due to the torque existing in the torsional spring and the damper between gyroscopes. The system is mounted on a vertical cantilever with the purpose of studying the horizontal and vertical vibrations. The equation of motion of the compound system (gyro-beam system) is introduced and solved to find the response measured on the primary system. This is fundamental to design, in some way, the dynamic absorber or neutralizer. On the other hand, the effect of the angular velocities of the gyroscopes are studied, and it is shown that the angular velocity (spin velocity) of a gyroscope has a significant effect on the behavior of the dynamic motion. Correctness of the analytical results is verified by numerical simulations. The comparison with the results from the derivation of the corresponding frequency equations shows that the optimized stiffness and damping values are very accurate.
- BildiriYalnız künye2016Determination of the ground-building relationships in the KTU campus area with microtremor measurements
Beker, Y.; Sayil, N.; Akin, O.; Coban, K.H.
Microtremor measurement obtained by ground vibrations is one of the useful methods for determination of ground characteristics. Also the method has been using to specify building resonance risk during earthquakes in the last decades. In this study, single station microtremor recordings have been taken on the ground and at the 6 buildings in the KTU campus area. The measurements taken on the ground and in the buildings have been evaluated by Nakamura (H/V ratio) method. The eastern of the campus area presents Class-IV and the middle and western part of the campus present Class-II- Class-III according to Kanai and Tanaka ground classification. The predominant frequencies of the buildings are not in a harmony with the values of the ground. It can be deduce that the resonance risk is low for these buildings during the earthquakes. The H/V ratios of the ground change between 1-3 and lower than the buildings ratios which change between 5.0-8.5.
- MakaleAçık Erişim2016Comparison of practices related to occupational health and safety in microscale wood-product enterprises
Top, Yener; Adanur, Hakan; Öz, Mehmet
Risk factors in the workplace vary according to the sector and scale of the business. Small and medium-sized enterprises, especially those within the scope of the wood-products manufacturing industry, are considered to be risky, and have a relatively high accident rate. Here, we focus on the timber and furniture industries, two subsectors of the wood-products industry. A total of 47 enterprises was visited and asked to participate in a formal structured questionnaire. The findings show that the usage of personal protective equipment (PPE) was low, that lighting was often inadequate, and that these enterprises typically lacked routine organising and cleaning practices. The subsectors and the occupational health and safety practices were found to be independent, and a statistically significant relationship could only be established between the subsectors in terms of the use of dust masks and goggles. Despite the unfavourable working conditions, only one business out of 47 reported having an employee with symptoms of occupational diseases.
- MakaleAçık Erişim2016Investigation of pozzolanic activity of volcanic rocks from the northeast of the Black Sea
Çullu, Mustafa; Bolat, Hakan; Vural, Alaaddin; Tuncer, Ertan
Mineralogical and chemical properties, as well as the pozzolanic activities, of the volcanic rocks in the northeast of the Black Sea were examined. Physical and mechanical tests were conducted on samples collected from the study area and the feasibility of using volcanic rocks as pozzolanic admixture in the concrete industry was investigated. Mortar samples containing admixture in the ratios of 0%, 10%, 20%, 30%, 40%, and 50% were prepared by keeping fineness of pozzolanic admixtures fixed. By using these mortar samples, prismatic mortar samples of 4×4×16 cm were prepared and the samples were cured in water. Their 7-, 28-, and 90-day tensile strengths, compressive strengths, and ultrasonic pulse velocity were determined. As a result, it was determined that volcanic rocks can be used to produce blended cement by considering their specific gravity, pozzolanic activities, and compressive strengths. It was noted that increase in trass rate significantly reduced tensile and compressive strength of cement in the early stage as expected.