107 research outputs found
The Effects of Material Properties on Building Performance
In recent earthquakes during the last two decades, severe damages have been occurred on
the existing buildings in Turkey. Destructive earthquakes revealed that the existing building
stock in urban regions is significantly vulnerable to seismic hazard. A large number of
residential buildings located in regions of high seismicity require performance evaluation
before the next big earthquake hits the region. In many earthquake resistant codes, several
procedures are proposed to determine the building performance. The investigations on the
damaged buildings show that material strengths are very important parameters on the building
performance. In this study, material strengths’ effects on the building performance were
investigated by using a nonlinear elastic analysis method
Effects of alfentanil or fentanyl added to propofol for sedation in colonoscopy on cognitive functions: Randomized controlled trial
Background/Aims: To assess the effect of propofol supplemented with alfentanil or fentanyl on cognitive functions
for sedation during elective colonoscopy.
Materials and Methods: Patients (n=150, 18-65 years old, American Society of Anesthesiologists risk group I-III)
scheduled undergo elective colonoscopy were included. They were randomized into three groups using the
closed envelope methodpropofol-alfentanil (Group A), propofol-fentanyl (Group F), and propofol only (Group
P).Group A patients were given an alfentanil (10 mcg/kg)-supplemented propofol bolus infusion and 5 mcg/
kg alfentanil when necessary. Group F patients were given fentanyl (1 mcg/kg)-supplemented propofol and 0.5
mcg/kg fentanyl when necessary. Group P patients were given 1 mg/kg propofol and 0.5 mg/kg propofol when
necessary. Vital signs, depth of sedation, recovery parameters, and patient and endoscopist satisfaction were
recorded. Trieger dot test (TDT) and Digit Symbol Substitution Test (DSST) were performed post procedure.
Results: Demographic data were similar among all patients in the groups. Bispectral index values were lower
in Group P (p<0.001). DSST scores were higher in Group A (p=0.004). TDT scores and Facial Pain Scale scores
were higher in Group P (p<0.005). Apnea incidence (p=0.009) and Observer’s Assessment of Alertness/Sedation
Scale scores (p=0.002) were also higher in Group P. Patient satisfaction and endoscopist satisfaction were similar
among all patients.
Conclusions: Compared with propofol-alfentanil and propofol-fentanyl, propofol alone is associated with an
increased incidence of apnea, drug consumption, and reported pain. Propofol-alfentanil has a less negative
effect on cognitive functions than propofol alone or propofol-fentanyl
Pemantauan Senyawa Dichlorodiphenyltrichloroethane (Ddt) dan Turunannya di Daerah Cianjur, Jawa Barat
Persistent Organic Pollutants (POPs) merupakan senyawa organik yang relatif bertahan lama di lingkungan, sulit terdegradasi melalui proses kimia, biologi, dan fotolisis serta sukar larut di dalam air tetapi cenderung larut dalam lemak. Oleh karena sifatnya ini, POPs cenderung bersifat akumulatif dan bertahan di lingkungan. Selain itu, senyawa ini juga bersifat semivolatil sehingga dapat berada dalam fase uap ataupun terserap di dalam partikel debu, sehingga POPs dapat menempuh jarak yang jauh di udara (long-range air transport) sebelum akhirnya terdeposisi di bumi. Dari beberapa bentuk senyawa POPs, senyawa insektisida organoklorin yang paling bertahan lama dan mempunyai sifat bioakumulasi, diantaranya adalah Dichlorodiphenyltrichloroethane ( DDT ). Pemantauan kualitas lingkungan akibat pencemaran kelompok senyawa POPs, termasuk senyawa DDT dan turunannya telah dilakukan didaerah holtikultura Cianjur. Sampel diambil di beberapa lokasi yaitu PLTA Cijedil, Desa Cibeureum, Desa Sukatani, Agropolitan, dan Desa Sindang Jaya. Matriks yang diambil adalah air, sedimen sungai, dan tanah pertanian/perkebunan. Sampling air dan sedimen sungai dilakukan dengan metode sesaat sedangkan untuk tanah, menggunakan metode komposit tempat. Pemantauan ini mempunyai tujuan untuk menginventarisir jenis dan konsentrasi residu senyawa POPs yang terdapat di lingkungan terutama DDT dan turunannya. Isomer DDT yang paling banyak terbentuk di lingkungan adalah p,p\u27-DDT ( 80 % ) dan o,p\u27-DDT ( 20 % ). Senyawa POPs diekstrak dengan menggunakan pelarut organik, kemudian di clean-up dan dianalisis dengan GCMS menggunakan kolom kapiler non polar. Pada pemantauan tahun 2011, senyawa p,p\u27-DDT tidak terdeteksi dalam sampel sedimen, tetapi pada tahun 2012, ditemukan sekitar 3.7 ng/g dalam sedimen Sungai Cibeureum dekat PLTA Cijedil, Cugenang -Jawa Barat dan meningkat sebesar 6.95 ng/g pada tahun 2012 di lokasi yang sama. Masih pada tahun 2011, p,p\u27-DDT dan p,p\u27-DDE ditemukan tertinggi di tanah perkebunan Desa Sindang Jaya, Cipanas – Jawa Barat sebesar 446 ng/g, dan 184 ng/g, Tahun 2012 dan 2013 DDT dan turunannya masih terdeteksi namun konsentrasi cenderung menurun. Sementara itu pada sampel air tidak ditemukan senyawa DDT dan turunanny
Machine Learning Applications in Dentistry
Artificial Intelligence has emerged as a breakthrough in many fields including medicine and dentistry where new approaches can be employed to solve challenging decision making processes faced in the dental field. Artificial intelligence can be used as a decision support mechanism to solve the increasing population and consequently the increasing dental treatment needs. It also assists dentists in diagnosis and treatment planning stages that require expert opinion. This mini-review covers some of the recent studies in this area and envisions future directions on the use of machine learning in dental problems
Remote Sensing And Geographical Information System Based Hydrological Modelling For Determination Of Hydroelectric Potential
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2008Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2008Bu çalışmada pilot bölge olarak seçilen Trabzon ili dahilinde ki Solaklı havzasına ait hidroelektrik potansiyel, uzaktan algılama ve coğrafi bilgi sistemi kullanılarak belirlenmiştir. Hidroelektrik potansiyeli belirlemek için gerekli iki parametre; suyun akım değeri (debi) ve suyun düşüm yüksekliğidir. Bu değerleri elde edebilmek yani hidroelektrik potansiyeli hesaplayabilmek için havzaya ait stereo çekim yapabilen Cartosat-1 uydu verileri kullanılmak suretiyle 3 boyutlu sayısal yükseklik modeli elde edilmiştir. Üretilen sayısal yükseklik modeli ArcGis coğrafi bilgi sistemi yazılımına yüklenmiş ve havzaya ait alan, çevre, eğim, ortalama yükseklik gibi topoğrafik parametreler elde edilmiştir. Ayrıca sayısal yükseklik modeli ve ArcGis yazılımı kullanılarak havzaya ait sentetik drenaj ağı, alt havzalar ve olası santral noktalarının belirlenmiştir. Havzaya ait alansal yağış haritası havza içersindeki yağış gözlem istasyonlarının verileri kullanılarak Kriging yöntemi ile bulunmuştur. Böylece her bir alt havzaya ait alansal yağış hesaplanmıştır. Çoklu regresyon denklemleri yardımıyla akım denklemi geliştirilmiş ve ArcGis yazılımı kullanılarak oluşturulan sentetik drenaj ağı üzerinde suyun akım miktarı bu denklem kullanılarak hesaplanmıştır. Çalışmanın son bölümünde sonuçlar tartışılmış ve yeni öneriler getirilmiştir.In this study, hydroelectric potential of Solaklı Basin, Trabzon which is considered as a pilot region was determined using remote sensing and geographic information system. Determination of hydroelectric potential requires flow value (discharge) and height of waterfall as input parameters. In order to obtain these parameters, 3-dimension digital elevation model was derived using satellite stereo data of Cartosat-1. Topographical parameters such as basin area, perimeter, slope, average elevation were derived by means of digital elevation model in geographic information system software, ArcGis. Synthetic drainage network, sub basins and potential station points were also determined using digital elevation model and ArcGis. Areal precipitation map of Solaklı basin was generated with the help of Kriging method using data of rain gauge stations that are available in the basin. Thus areal precipitation of each sub basin was computed from the map. Flow equation was derived using multiple-linear regression. Flow values on the synthetic drainage network were evaluated from the flow equation using ArcGis. In the final chapter of this study, results were discussed and new suggestions were offeredYüksek LisansM.Sc
Role of F18-FDG PET/CT scanning in pleural malignancy
Retrospektif özellikteki bu çalışmada plevra lezyonlarının benign/malign ayrımında Fluorodeoksiglikoz (FDG)-Pozitron Emisyon Tomografisi/Bilgisayarlı Tomografi (PET/BT) görüntülemenin önemi, lezyonların metabolik aktiviteleri ile malignite potansiyelleri arasındaki ilişki, MPM'da hastalığın evrelenmesinde ve prognozunu belirlemede PET/BT görüntülemenin önemi araştırıldı.Çalışmamıza plevral malignite ön tanısı veya histopatolojik tanısı ile refere edilmiş tanı/evreleme amaçlı PET/BT görüntülemesi yapılmış toplam 40 hasta dahil edildi. Hastalar PET/BT çekim endikasyonlarına göre iki gruba ayrıldı. 1. grupta plevral kalınlaşma, plevral kitle, plevral effüzyon ve plevral plak gibi konvansiyonel görüntüleme bulguları olan plevral malignite ön tanısı ile refere edilmiş toplam 25 hasta incelendi. Bu hastalarda plevra lezyonlarının histopatolojik sonuçları ile PET/BT görüntülemelerinden elde edilen bu lezyonlara ait Maksimum Standart Uptake Value (SUVmax) değerleri karşılaştırıldı. SUVmax ortalama değeri benign lezyonlarda 2,55 (1,50-6,50); malign lezyonlarda 9,50 (6,20-18,10) olarak hesaplandı ve istatistiksel olarak anlamlı kabul edildi (p<0,001). 2. grupta MPM histopatolojik tanısı olan evreleme amaçlı PET/BT görüntüleme yapılmış toplam 28 hasta incelendi. MPM histopatolojili plevral lezyonlarda ortalama SUVmax değeri 8,05 (4,50-14,20) olarak hesaplandı. 15 hastada (%53,6) metabolik aktivite gösteren mediastinal lenf nodları mevcuttu ve lenf nodlarında ortalama SUVmax değeri 5,20 (1,80-11,90) idi. 7 hastada (%25) uzak metastazla uyumlu hipermetabolik servikal lenfadenopati, kontrlateral akciğer, karaciğer, surrenal gland ve kemik lezyonları mevcuttu. 14 hastada (%50), ortalama 15,5 aylık (6-29 ay) takip süresi boyunca cerrahi ve/veya medikal tedavi sonrası nüks/metastaz gibi progresyon bulgularının geliştiği, 7 hastanın ise hayatını kaybettiği saptandı. Kötü prognozlu bu 14 hastada plevral lezyonların SUVmax ortalama değeri 9,11 (±2,30), progresyon bulgusu saptanmayan diğer 14 hastada 6,97(±3,06) olarak ölçüldü ve istatistiksel olarak anlamlı kabul edildi (p=0,047).In this retrospective study; importance of Fluorodeoxyglucose (FDG)- Positron Emission Tomography/Computed tomography (PET/CT) scanning for determination of the pleura lesions being benign or malign, relationship between metabolic activities of the lesions and malignancy potentials, importance of PET/CT scanning in determination of the staging and prognosis of the MPM were researched.Total of 40 patients who were referred with pleural malignancy pre-diagnosis or histopathological diagnosis and scanned with PET/CT for diagnosis/staging purposes were included to our study. Patients were separated into two groups according to their PET/CT scan indications. In the 1st group; total of 25 patients who had conventional scanning findings such as pleural thickening, pleural mass, pleural effusion and pleural plaque and were referred with pleural malignancy pre-diagnosis were examined. In these patients histopathological results of the pleura lesions were compared with maximum Standardised Uptake Value (SUVmax ) of these lesions acquired from PET/CT scans. Average SUVmax value in the benign lesions were calculated as 2,55 (1,50-6,50); average SUVmax value in the malign lesions were calculated as 9,50 (6,20-18,10) and this was accepted as statistically significant (p<0,001). In the 2nd group, a total of 28 patients who had histopathological diagnosis of MPM and were scanned with PET/CT for staging purposes were examined. Average SUVmax value in the pleural lesions with MPM histopathology was calculated as 8,05 (4,50-14,20). 15 of the patients (%53,6) had mediastinal lymph nodes with metabolic activity and average SUVmax value of lymph nodes were 5,20 (1,80-11,90). In 7 patients (%25); there were hyper-metabolic cervical lymphadenopathy compatible with distant metastasis, contralateral lung, liver, adrenale gland and bone lesions. It was observed that 14 patients (%50) have developed progression findings such as post-operative recurrence/metastases during average 15,5 months follow-up period (6-29 months) and 7 patients were deceased. Average SUVmax value in the pleural lesions this 14 patients with bad prognosis was measured as 9,11 (±2,30); and average SUV max value in the pleural lesions of the other 14 patients, who had no progression findings were measured as 6,97 (±3,06) and this was accepted as statistically significant (p=0,047)
Bulk Flotation of Low Grade Refractory Sulfide Lead-Zinc Ore
In this research, bulk flotation from a low-grade refractor lead-zinc ore containing 3.5 % Zn and 1 % Pb and 1.9 % Fe was studied. Due to the problems involving sequential flotation of finely disseminated lead-zinc sulfide ore, the production of bulk lead-zinc concentrate was practiced. Flotation parameters such as activator (CuSO4) dosage, collector type [potassium amyl xanthate, sodium isopropyl xanthate] and dosage, flotation time, particle size and pH were investigated. Experimental results showed that collector dosage was the most significant factor affecting Zn and Pb recoveries. In the bulk flotation stage where 100 g/t CuSO4 and 150 g/t potassium amyl xanthate were used (at pH 8 and 10 min flotation time) maximum Zn and Pb recoveries were obtained as 94 and 83 To, respectively
Investigation of metal recovery methods from zinc plant residue
Günümüzde yüksek tenörlü cevherlerin azalması ve gelişen teknolojiyle birlikte ikincil kaynakların değerlendirilme olanaklarının artması, pek çok artık madde içerisindeki değerli metallerin yeniden kazanılmasını zorunlu kılmaktadır. Bu çalışmada Çinkur tesisi liç artıklarından çinko, kurşun ve gümüşün hidrometalurjik yöntemlerle yeniden kazanılmasıyla ilgili araştırmalar yapılmıştır. Tesis artığının değerlendirilmesiyle ilgili olarak, başlangıçta metal tuzu oluşturmak ve artık bünyesinde bulunan çinko ferrit yapısını bozmak amacıyla sülfatlama kavurması, su liçi testleri için etken parametreler araştırılmıştır. Liç işlemi sonrasında, elde edilen çözeltiden demirin uzaklaştırılması için jarosit ve goethit prosesleri uygulanmıştır. Ancak jarosit olarak demirin istenilen oranda uzaklaştırılması mümkün olmamış, goethit prosesiyle ise demirin %99,99'unun çözeltiden uzaklaştırılması sağlanmıştır. Goethit prosesinde amonyum peroxodisülfat kullanımıyla, demirle birlikte mangan ve kobaltın yüksek oranda çöktürülmesi mümkün olmuştur. Demir çöktürme işleminden sonra çözelti içerisinde yer alan empürite metal iyonlarını uzaklaştırmak için modifiye edilmiş sementasyon işlemi uygulanmıştır. Sementasyon işlemlerinde çinko tozu boyutu ve miktarı, sıcaklık, katkı maddelerinin etkisi, sementasyon süresi ve karıştırma hızı gibi parametreler optimize edilerek sementasyon kinetiği ve mekanizması ortaya konmuştur. Ayrıca kurşun ve gümüşün kazanım çalışmalarında ise kurşun kekine NaCl liçi uygulanarak, en uygun koşullar belirlenmiştir. Liç artığından hidrometalurjik olarak, çinko, kurşun ve gümüşün kazanılmasının mümkün olduğu saptanmış ve elde edilen sonuçlar ışığında bir tesis akım şeması önerilmiştir. At present, with the decrease in high grade ores and the possibility of processing secondary deposits with new developed technology necessiate the need of recovering valuable minerals from mineral processing and metalurgical tailings. In this study, recovery of zinc, lead and silver from the Çinkur zinc plant residues by hidrometallurgical methods was investigated. To investigate the recovery methods of the residues, the structure of zinc ferrite contained in the residues was altered by sulfate roasting first, and followed by water leach tests. Empirical variables affecting the process were investigated in this study. To remove the iron from the leach solution (leachate), goethite and jarosite proseses were applied, however, iron was not able to be removed successfully by jarosite process. However, 99.99% of iron was removed from the leachate by goethite prosess. In addition to iron, manganese and cobalt can also be precipitated by geothite prosess using amonium peroxodisulfate. After the iron removing process, a modified cementation process was used to remove the metal ion impurities from the solution. Empirical variables affecting the cementation process, such as, zinc dust size and amount, temperature, duration, and mixing speed, were investigated and optimized in this study to determine cementation kinetics and mechanism. In addition, the most feasible method for the recovery of lead and zinc was shown to be treating the lead cake by NaCl. Recovery of zinc, lead and silver from leach tailings by hydrometallurgical metods was accomplished and based on the results of this investigation a flowsheet showinng the recovery steps was developed
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