Patch Burning: Implications on Water Erosion and Soil Properties

Patch burning can be a potential management tool to create grassland heterogeneity and enhance forage productivity and plant biodiversity, but its impacts on soil and environment have not been widely documented. In summer 2013, we studied the effect of time after patch burning (4 mo after burning [recently burned patches], 16 mo after burning [older burned patches], and unburned patches [control]) on vegetative cover, water erosion, and soil properties on a patch-burn experiment established in 2011 on a Yutan silty clay loam near Mead, NE. The recently burned patches had 29 ± 8.0% (mean ± SD) more bare ground, 21 ± 1.4% less canopy cover, and 40 ± 11% less litter cover than older burned and unburned patches. Bare ground and canopy cover did not differ between the older burned and unburned patches, indicating that vegetation recovered. Runoff depth from the older burned and recently burned patches was 2.8 times (19.6 ± 4.1 vs. 7.1 ± 3.0 mm [mean ± SD]) greater than the unburned patches. The recently burned patches had 4.5 times greater sediment loss (293 ± 89 vs. 65 ± 56 g m-2) and 3.8 times greater sediment-associated organic C loss (9.2 ± 2.0 vs. 2.4 ± 1.9 g m-2) than the older burned and unburned patches. The recently burned patches had increased daytime soil temperature but no differences in soil compaction and structural properties, dissolved nutrients, soil C, and total N concentration relative to older burned and unburned patches. Overall, recently burned patches can have reduced canopy and litter cover and increased water erosion, but soil properties may not differ from older burn or unburned patches under the conditions of this study

Diesel engine fuel injection monitoring using acoustic measurements and independent component analysis

Air-borne acoustic based condition monitoring is a promising technique because of its intrusive nature and the rich information contained within the acoustic signals including all sources. However, the back ground noise contamination, interferences and the number of Internal Combustion Engine ICE vibro-acoustic sources preclude the extraction of condition information using this technique. Therefore, lower energy events; such as fuel injection, are buried within higher energy events and/or corrupted by background noise. This work firstly investigates diesel engine air-borne acoustic signals characteristics and the benefits of joint time-frequency domain analysis. Secondly, the air-borne acoustic signals in the vicinity of injector head were recorded using three microphones around the fuel injector (120° apart from each other) and an Independent Component Analysis (ICA) based scheme was developed to decompose these acoustic signals. The fuel injection process characteristics were thus revealed in the time-frequency domain using Wigner-Ville distribution (WVD) technique. Consequently the energy levels around the injection process period between 11 and 5 degrees before the top dead center and of frequency band 9 to 15 kHz are calculated. The developed technique was validated by simulated signals and empirical measurements at different injection pressure levels from 250 to 210 bars in steps of 10 bars. The recovered energy levels in the tested conditions were found to be affected by the injector pressure settings

Sources of residual autocorrelation in multiband task fMRI and strategies for effective mitigation

In task fMRI analysis, OLS is typically used to estimate task-induced activation in the brain. Since task fMRI residuals often exhibit temporal autocorrelation, it is common practice to perform prewhitening prior to OLS to satisfy the assumption of residual independence, equivalent to GLS. While theoretically straightforward, a major challenge in prewhitening in fMRI is accurately estimating the residual autocorrelation at each location of the brain. Assuming a global autocorrelation model, as in several fMRI software programs, may under- or over-whiten particular regions and fail to achieve nominal false positive control across the brain. Faster multiband acquisitions require more sophisticated models to capture autocorrelation, making prewhitening more difficult. These issues are becoming more critical now because of a trend towards subject-level analysis, where prewhitening has a greater impact than in group-average analyses. In this article, we first thoroughly examine the sources of residual autocorrelation in multiband task fMRI. We find that residual autocorrelation varies spatially throughout the cortex and is affected by the task, the acquisition method, modeling choices, and individual differences. Second, we evaluate the ability of different AR-based prewhitening strategies to effectively mitigate autocorrelation and control false positives. We find that allowing the prewhitening filter to vary spatially is the most important factor for successful prewhitening, even more so than increasing AR model order. To overcome the computational challenge associated with spatially variable prewhitening, we developed a computationally efficient R implementation based on parallelization and fast C++ backend code. This implementation is included in the open source R package BayesfMRI.Comment: 26 pages with 1 page of appendix, 11 figures with 1 figure of supplementary figur

Electropolymerization of carbazole and 3,4 (etyhlenedioksithiophene) comonomer on carbon fiber microelectrode

Polikarbozol(PCz) ve poli(3,4 etilen dioksitiyofen)(PEDOT) ikisi de oldukça kararlı polimerlerdir. Fakat Poly(EthylCz) (PECz)’ün iletkenliği PEDOT’a oranla oldukça düşüktür. Polikarbazol ve PEDOT alternatif kopolimerleri sentezlendiğinde PCz’ün iletkenliğinin artırılması, her iki polimerin arasındaki etkileşimden dolayı homopolimerlerden daha üstün özellikleri olan bir kopolimer elde edilmesi amaçlanmıştır. Uç grubu Ecz olan Ecz-BEDOT-Ecz komonomeride sentezlenmiştir. Böylelikle BEDOT komonomeri yapısına Ecz’ü de katılarak komonomerin konjugasyon boyutu uzamıştır. Ecz-BEDOT-Ecz karbon fiber üzerinde polimerleşirken Platin üzerinde tıpkı Ecz homopolimerine benzer şekilde polimerleşmemiş sadece oligomer oluşumu UV spektroskopisinde gözlenmiştir. EBEE’nin karbon fiber üzerine kaplanması 1.3V uygulayarak 100mV/s tarama hızında döngülü voltamogram ile gerçekleştirilmiştir. Bu sonuç kullanılan elektrot tipinin polimeri-zasyon mekanizmasını etkilediğini kanıtlamaktadır. Kaplanan PEBEE’nin elektron transferine ait olan birinci redoks prosesi 0.88V’da, ikinci redoks prosesi ise 1.22V’dadır. Bu ikinci pikin çok daha yüksek olması orada hem komonomerin hemde kopolimerin bu potansiyelde oksitlenebilmesidir. Komonomerdeki ECz uç grubu; kopolimerin fiziksel özelliklerini iyileştirmeye büyük katkısı olmuştur. Elde edilen kopolimerin redoks davranışı Ecz’ün homopolimerine benzer özellik taşımaktadır. PEBEE’nin oksidasyon potansiyeli 0.4V’dur. Dolayısıyla PECz’dan daha küçüktür. Bu veriye dayanarak konjugasyon uzunluğunun arttığını ve elde edilen alternatif kopolimerin iletkenliğinin PECz’den yüksek olduğu sonucunu çıkarabiliriz. PBEDOT’ın oksidasyon potansiyeli düşük olduğundan oda koşullarında saklanamamaktadır. Alternatif kopolimer eldesiyle PBEDOT’ın kararlılığını arttırdığı görülmüştür. PEBEE’ yi homojen olarak karbon fiber üzerine kaplamak için pek çok koşul denenmiş, fakat en homojen kaplamanın  düşük polimerizasyon hızında (20mV/s) ve 50 döngü saysında elde edilebilmiştir. Anahtar Kelimeler: Cz, EDOT, elektropolimerizasyon, iletken polimer, karbon fiber.PEDOT, was initially developed to give a soluble conducting polymer that lacked the presence of undesired a-b, and b-b,couplings within the polymer backbone. Prepared using standard oxidative chemical or electrochemical polymerization methods, PEDOT was initially found to be an insoluble polymer,   yet exhibited some very interesting properties. In addition  to a very high conductivity,, PEDOT was found to be almost transparent in thin, oxidized films and showed a very high stability in the oxidized state. Polycarbazole, among conducting polymers, is attributed with good electroactivity, and useful thermal, electrical andphotophysical properties. However, p®p electron system along its backbone imparts rigidity to the polymer and, therefore, makes it infusible and poorly processable. Due to this reason, it was not initially employed as widely in devices as other conducting polymers. Recent advances in synthesis methods have, however, revived interest in polycarbazole . Investigations related to chemical modification or co-polymerization of carbazole with other monomers have led to the use of polycarbazole and its derivatives as redox catalysts, photoactive devices, sensors, electrochromic display, electroluminescent devices and biosensors . A new co-monomer EBEE has been firstly synthesized, characterized and electropolymerized on CFME and Pt. Side group of monomer play an important role on the physical properties of resulting copolymer and it resembles the behavior of homopolymer of monomer at the end of co-monomer,namely ethylcarbazole. Environmental stability of PBEDOT was increased by incorporation of ECz monomer into structure. For ECz ending monomers CFME seems better substrate than Pt to obtain an electroactive polymer film. EBEE comonomer synthesized first time and electropolymerized on Pt and CFME. ECz was also electropolymerized on CFME in order to compare with Poly(EBEE) and to gain further information. Cyclic voltammogram of electrogrowth  of Poly(EBEE) obtained on CFME ,exhibits two oxidative processes at 0.88V and 1.22 V. Appearance of green color on the electrode surface, higher value of current intensities inaccordance with Pt electrode and increase in the current density with increasing scan number suggests a polymer film on CFME. Although current intensities increase as the scan number increases, deposition process or insoluble film formation could not be detected in any experiments and the color of solution converted to blue when Pt electrode was used as a working electrode. Ex-situ UV of solution was taken during electropolymerization, the results indicated that when it is increased time exposed to potential amount of oligomer increased.This might be due to so-called oligomer approach that accepted recently. In this approach it is suggested that after the formation of a dimer a sequence of subsequent dimerization step leads to the formation of soluble oligomers. All this reaction probably occurs in solution without or only small precipitation on electrode. In our case after dimerization and/or tetramer formation further coupling reaction become very slow due to decrease in the rate constant. Formation of only soluble oligomers was also supported by solution color which turns from light yellow to green as reaction proceeds. In the light of all these results it can be concluded that  solubility of oxidized product of ECz-BEDOT-ECz  on Pt electrode might be due to either characteristic behavior of ECz  or stop of polymerization and/or became very slow at oligomerization level as suggested by oligomer approach. ECz-BEDOT-ECz polymerization mechanism depends on the switching potentials and chemical reaction became important at higher switching potential. The scan rate used have an effect on the homogenity of the resultant film. In literature, it is known that ECz is not electropolymerized in except acidic conditions; however, we observed that ECz can be electropolymerized on CFME under mentioned experimental conditions. CV of PECz coated CFME electrodes in monomer free electrolyte shows two step oxidation at 0.93V and 1.23 V which has promising properties and need to  further investigation. Comparison of results with previous study reveal the fact  that chemical make up play an important role on the properties of resulting polymers. The polymer obtained at 100mV/s and different cycle numbers polymer coating was heteregenous. Regular polymer growth is observed only 20mV/s scan rate with 50cycle. A globular structure resulting from a three dimensional nucleation growth mechanism as observed only in that case. The SEM structure of PEBEE shows small clusters of globules.The morphology of polymers obtained with 100mV/s scan rate were quite different from that of obtained with 20mV/s. Keywords: Cz, EDOT, electropolymerization, carbon fiber microelectrode

Assessment of subjective sleep quality in iron deficiency anaemia

Objectives: We aimed to assess the effect of anemia on subjective sleep quality in patients with iron deficiency anemia (IDA).Methods: One hundred and four patients diagnosed with IDA and 80 healthy individuals, who are gender and age matched, were included in the study. All participants were requested to fill 3 forms: a socio-demographic form (age, gender, marital status, income level and educational status), hospital anxiety and depression (HAD) scale and pittsburgh sleep quality index (PSQI).Results: According to the HAD scale, the average anxiety score was found 9.24±4.37 in patients and 7.58± 4.07 in controls. And, the average depression score was 7.53±4.10 in patients and 6.41±2.74 in controls. The total sleep quality score was 6.71±3.02 in patients and 4.11±1.64 in controls. There was a statistically significant difference in terms of anxiety, depression and sleep quality scores. Linear regression analysis showed no association between anxiety and depression with poor sleeping.Conclusion: IDA affects sleep quality irrespective of psychological symptoms such as depression and anxiety.Keywords: Iron deficiency anemia, sleep quality, anxiet

AgInSe2 ve AgGaSe2 ince filmlerin ısısal buharlaştırma ve saçtırmalı kaplama teknikleriyle büyütülmesi ve n-CdS/p-AgGaSe2, p-Si/nAgInSe2 ve n-CdS/p-AgInSe2 pn-heteroeklem güneş hücrelerinin oluşturulması

TÜBİTAK TBAG15.06.2011Bu proje kapsamında, I-III-VI gurubu kalkopirit bileĢiklerinden olan AgInSe2 (AIS) ve AgGaSe2 (AGS) ince filmler üç farklı kaplama, ısısal (thermal), elektron demeti(e-beam) ve DC/RF manyetik saçtırmalı (sputtering) buharlaştırma yöntemleri kullanılarak üretilmiştir. Projenin ilk aşamasında, cam tabanlar üzerinde kaplanan filmlerin elektriksel, optik, yapısal ve yüzeysel özellikleri XRD, SEM, EDS ve XPS ölçümleri alınarak belirlenmiş ve büyütme koşulları optimize edilmiştir. Isısal ve elektron demeti yöntemiyle kaplama için, buharlaştırmada kullanılacak kaynak malzeme saf Ag, In, Ga ve Se elementleri istenilen oranda kuvartz tüpler içerisine istenen içerikte yerleştirilip, vakumlanarak Bridgman kristal çekme sistemiyle AgInSe2 ve AgGaSe2 kristalleri sentezlenmiş ve buharlaştırma kaynağı olarak kullanılmıştır. Üçüncü olarak ise daha önce çok fazla uygulanmamış olan, RF/DC manyetik saçtırma tekniğiyle, AgInSe2 ve AgGaSe2 ince fılmler katmanlar halinde farklı kalınlıklarda, aynı vakum ortamında, vakumu bozmadan üç kaynaklı saçtırmalı buharlaştırma sistemi kullanılarak, farklı alttaşlar üzerine katmanlar halinde Ag/InSe/Ag... kaplanmış, sonrasında üçlü bileşik yapısının oluşması için filmlerin 200-500 oC derece arasında tavlanmıştır. Ayrıca kaplama ve tavlama sırasında yapı içerisindeki Se ayrışmasını ortadan kaldırmak için baĢka bir sistemde selenyum atmosferinde 300-500 oC‟de, 30 dakika tavlanmıştır. Çalışmanın takip eden son aşamasında her üç yöntemle hazırlanan ince filmler kullanılarak; Mo/p-AgInSe2, p-Si/n-AgInSe2, n-CdS/p-AgInSe2, Mo/n-AgGaSe2/p-AgInSe2, gibi farklı pn-heteroeklem ve metal/yarıiletken aygıt yapıları oluşturularak, karanlık ve aydınlık akım-voltaj (I-V), farklı frekanslarda kapasitans-voltaj(C-V) ve 400-1200 nm arasında spektral fotoakım ölçümleri alınarak aygıt parametreleri tespit edilmiştir. Ayrıca güneş benzeticisi kullanılarak AM1 şartlarında verimlilikleri ölçülmüştür.In the scope of this project, the members of I-III-VI groups of ternary chalcogonide compounds, namely AgInSe2 (AIS) and AgGaSe2 (AGS) thin films have been deposited by means of thermal evaporation, e-beam and RF/DC magnetron sputtering deposition techniques. In the first part of the project, electrical, optical, structural and morphological properties of thin films deposited on glass substrates by taking XRD, SEM, EDS and XPS measurements were analyzed and the growth conditions were optimized. The evaporation source material for thermal and e-beam deposition methods were prepared by mixing and placing the desired molecular content of pure Ag, Ga, In and Se elements into quartz ampoule and sealing it under vacuum. Then, the ampoule was placed through Brigdman crystal system to produce the single crystals of AgInSe2 and AgGaSe2, and they were used as the evaporation source in these methods. RF/DC magnetron sputtering was used as third evaporation method, which is not used so frequently in this kind of study. By using this method, AgInSe2 and AgGaSe2 were deposited on different substrates, especially on glass substrates layer by layer growth of each Ag, InSe and GaSe targets in different thickness and sequences such as Ag/InSe/Ag...Then, deposited films were annealed at the same chamber under vacuum in the range of 200-500 oC in order to form ternary compounds by controlling the diffusion of the constituent elements. Also, the grown thin films were annealed under selenium atmosphere in between 300 and 500 oC for 30 min. in another vacuum chamber to compensate the Se segregation. In the final part of this study, the thin films deposited by these three techniques were used to produce different np- or pn-heterojunction and metal/semiconductor device structure Mo/p-AgInSe2, p-Si/n-AgInSe2, n-CdS/p-AgInSe2, Mo/n-AgGaSe2/p-AgInSe2, and their dark and illuminated current-voltage (I-V), capacitance- voltage(C-V) at different frequencies and spectral-photocurrent in the wavelength range of 400-1200 nm were measured and their device parameters were investigated. The solar efficiency of the devices with the solar simulator under AM1 condition was also measured