Probing Top Anomalous Couplings at the Tevatron and the Large Hadron Collider

Chromomagnetic and chromoelectric dipole interactions of the top quark are studied in a model independent framework. Limits are set on the scale of new physics that might lead to such contributions using available Tevatron data. Prospects at the LHC are reviewed.Comment: Version published in Praman

Electric field dependence of Raman-active modes in single-wall carbon nanotube thin films

We report on electrical Raman measurements in transparent and conducting single-wall carbon nanotube (SWNT) thin films. Application of external electric field results in downshifts of the D and G modes and in reduction of their intensity. The intensities of the radial breathing modes increase with electric field in metallic SWNTs, while decreasing in semiconducting SWNTs. A model explaining the phenomenon in terms of both direct and indirect (Joule heating) effects of the field is proposed. Our work rules out the elimination of large amounts of metallic SWNTs in thin film transistors using high field pulses. Our results support the existence of Kohn anomalies in the Raman-active optical branches of metallic graphitic materials [Phys. Rev. Lett. 93 (2004) 185503].Comment: 17 pages, 4 figure

Türkiye'de ülke içinde yerinden edilme sorunu: tespitler ve çözüm önerileri = The problem of internal displacement in Turkey: assessment and policy proposals

Bu rapor, Doç. Dr. A. Tamer Aker (psikiyatr, Kocaeli Üniversitesi), Yrd. Doç. Dr. A. Betül Çelik (siyaset bilimci, Sabancı Üniversitesi), Dilek Kurban (hukuk doktoru, TESEV), Doç. Dr. Turgay Ünalan (nüfusbilimci, Hacettepe Üniversitesi) ve Yrd. Doç. Dr. H. Deniz Yükseker'den (sosyolog, Koç Üniversitesi) oluşan TESEV Ülke İçinde Yerinden Edilme Araştırma ve İzleme Grubu tarafından hazırlanmıştır. Grup, yerinden edilmeyi çatışma ortamının keskinleştirdiği devlet merkezli düşünüşün ve çeşitli ideolojik kamplaşmaların ötesinde, yurttaşlık haklarının yeniden tesisi ve toplumsal rehabilitasyon eksenlerinde ve insani boyutları bağlamında ele almaktadır

Controlled Growth, Patterning and Placement of Carbon Nanotube Thin Films

Controlled growth, patterning and placement of carbon nanotube (CNT) thin films for electronic applications are demonstrated. The density of CNT films is controlled by optimizing the feed gas composition as well as the concentration of growth catalyst in a chemical vapor deposition process. Densities of CNTs ranging from 0.02 CNTs/{\mu}m^2 to 1.29 CNTs/{\mu}m^2 are obtained. The resulting pristine CNT thin films are then successfully patterned using either pre-growth or post-growth techniques. By developing a layered photoresist process that is compatible with ferric nitrate catalyst, significant improvements over popular pre-growth patterning methods are obtained. Limitations of traditional post-growth patterning methods are circumvented by selective transfer printing of CNTs with either thermoplastic or metallic stamps. Resulting as-grown patterns of CNT thin films have edge roughness (< 1 {\mu}m) and resolution (< 5 {\mu}m) comparable to standard photolithography. Bottom gate CNT thin film devices are fabricated with field-effect mobilities up to 20 cm^2/Vs and on/off ratios of the order of 10^3. The patterning and transfer printing methods discussed here have a potential to be generalized to include other nanomaterials in new device configurations

A measurement of the top quark's charge

The top quark was discovered in 1995 at the Fermilab National Accelerator Laboratory (Fermilab). One way to confirm if the observed top quark is really the top quark posited in the Standard Model (SM) is to measure its electric charge. In the Standard Model the top quark is the isospin partner of the bottom quark and is expected to have a charge of +2/3. However, an alternative 'exotic' model has been proposed with a fourth generation exotic quark that has the same characteristics, such as mass, as our observed top but with a charge of -4/3. This thesis presents the first CDF measurement of the top quark's charge via its decay products, a W boson and a bottom quark, using {approx} 1 fb{sup -1} of data. The data were collected by the CDF detector from proton anti-proton (p{bar p}) collisions at {radical}s = 1.96 TeV at Fermilab. We classify events depending on the charges of the bottom quark and associated W boson and count the number of events which appear 'SM-like' or 'exotic-like' with a SM-like event decaying as t {yields} W{sup +}b and an exotic event as t {yields} W{sup -}b. We find the p-value under the Standard Model hypothesis to be 0:35 which is consistent with the Standard Model. We exclude the exotic quark hypothesis at an 81% confidence level, for which we have chosen a priori that the probability of incorrectly rejecting the SM would be 1%. The calculated Bayes Factor (BF) is 2 x Ln(BF)=8.54 which is interpreted as the data strongly favors the Standard Model over the exotic quark hypothesis

Physical and Antibacterial Properties of Peppermint Essential Oil Loaded Poly (ε-caprolactone) (PCL) Electrospun Fiber Mats for Wound Healing

The aim of this study was to fabricate and characterize various concentrations of peppermint essential oil (PEP) loaded on poly(ε-caprolactone) (PCL) electrospun fiber mats for healing applications, where PEP was intended to impart antibacterial activity to the fibers. SEM images illustrated that the morphology of all electrospun fiber mats was smooth, uniform, and bead-free. The average fiber diameter was reduced by the addition of PEP from 1.6 ± 0.1 to 1.0 ± 0.2 μm. Functional groups of the fibers were determined by Raman spectroscopy. Gas chromatography-mass spectroscopy (GC-MS) analysis demonstrated the actual PEP content in the samples. In vitro degradation was determined by measuring weight loss and their morphology change, showing that the electrospun fibers slightly degraded by the addition of PEP. The wettability of PCL and PEP loaded electrospun fiber mats was measured by determining contact angle and it was shown that wettability increased with the incorporation of PEP. The antimicrobial activity results revealed that PEP loaded PCL electrospun fiber mats exhibited inhibition against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacteria. In addition, an in-vitro cell viability assay using normal human dermal fibroblast (NHDF) cells revealed improved cell viability on PCL, PCLPEP1.5, PCLPEP3, and PCLGEL6 electrospun fiber mats compared to the control (CNT) after 48 h cell culture. Our findings showed for the first time PEP loaded PCL electrospun fiber mats with antibiotic-free antibacterial activity as promising candidates for wound healing applications

Enhanced Second Harmonic Generation from Coupled Asymmetric Plasmonic Metal Nanostructures

We show that second harmonic generation can be enhanced by Fano resonant coupling of asymmetric plasmonic metal nanostructures. We develop a theoretical model examining the effects of electromagnetic interaction between two metal nanostructures on the second harmonic generation. We compare the second harmonic generation efficiency of a single plasmonic metal nanostructure with that of two coupled ones. We show that second harmonic generation from a single metal nanostructure can be enhanced about 30 times by attaching a second metal nanostructure with a 10 times higher quality factor than that of the first one. The origin of this enhancement is Fano resonant coupling of the two metal nanostructures. We support our findings on Fano enhancement of second harmonic generation by an experimental study of a coupled plasmonic system composed of a silver nanoparticle and a silver nanowire on glass surface in which the ratio of the quality factors are also estimated to be around 10 times

Evaluation of Electrospun Poly(ε-Caprolactone)/Gelatin Nanofiber Mats Containing Clove Essential Oil for Antibacterial Wound Dressing

The objective of this study was to produce antibacterial poly(ε-caprolactone) (PCL)-gelatin (GEL) electrospun nanofiber mats containing clove essential oil (CLV) using glacial acetic acid (GAA) as a “benign” (non-toxic) solvent. The addition of CLV increased the fiber diameter from 241 ± 96 to 305 ± 82 nm. Aside from this, the wettability of PCL-GEL nanofiber mats was increased by the addition of CLV. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the presence of CLV, and the actual content of CLV was determined by gas chromatography–mass spectrometry (GC-MS). Our investigations showed that CLV-loaded PCL-GEL nanofiber mats did not have cytotoxic effects on normal human dermal fibroblast (NHDF) cells. On the other hand, the fibers exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli. Consequently, PCL-GEL/CLV nanofiber mats are potential candidates for antibiotic-free wound healing applications

MAY PPAR GAMMA BE SIGNIFICANT IN BIPOLAR DISORDER ONLY IN THE PRESENCE OF METABOLIC SYNDROME?

Background: Peroxisome proliferator-activated receptor γ (PPARγ) has a key role in regulating both neurogenesis and various metabolic processes, including adipogenesis and glucose homeostasis. In this study, it was aimed to compare the serum PPARγ levels and metabolic syndrome (MetS) parametres of patients with Bipolar Disorder (BD) diagnosed manic-depressive-euthymic episodes with those of healthy subjects. Subjects and Methods: We included 121 male patients with BD type I, 44 in mania, 35 in depression and 42 in euthymic state, and 41 healthy controls. Serum PPARγ levels, inflammation indicators (CRP, neutrophil, leukocyte, and albumin) and Mets parametres were measured. Results: There were no statistically significant differences between the groups in terms of PPARγ values. PPARγ serum level is highest in the control group and then euthymic, manic and depressive episodes continue to decrease, respectively. However, there was a significant difference between the depressive group with MetS and without MetS in terms of serum PPARγ levels. A statistically significant correlation was found between PPARγ and the other serum markers such as low-density lipoprotein (p=0.022), HbA1c (p=0.002), neutrophils levels (0.001), white blood cell (p=0.025), and clinical features such as age at first treatment (p=0.024), age at first episode (p=0.039), and smoking (0.013). Conclusions: We suggest that PPARγ may be a key factor in the BD depressive group with MetS. Not finding any relationship between the PPARγ levels and the episode of BD may be related with the absence of MetS in the individuals. MetS parametres must also be considered if PPARγ is to be evaluated in the future investigations