Search

Significance: Time domain diffuse correlation spectroscopy (TD-DCS) can offer increased sensitivity to cerebral hemodynamics and reduced contamination from extracerebral layers by differentiating photons based on their travel time in tissue. We have developed rigorous simulation and evaluation procedures to determine the optimal time gate parameters for monitoring cerebral perfusion considering instrumentation characteristics and realistic measurement noise. Aim: We simulate TD-DCS cerebral perfusion monitoring performance for different instrument response functions (IRFs) in the presence of realistic experimental noise and evaluate metrics of sensitivity to brain blood flow, signal-to-noise ratio (SNR), and ability to reject the influence of extracerebral blood flow across a variety of time gates to determine optimal operating parameters. Approach: Light propagation was modeled on an MRI-derived human head geometry using Monte Carlo simulations for 765- and 1064-nm excitation wavelengths. We use a virtual probe with a source–detector separation of 1 cm placed in the pre-frontal region. Performance metrics described above were evaluated to determine optimal time gate(s) for different IRFs. Validation of simulation noise estimates was done with experiments conducted on an intralipid-based liquid phantom. Results: We find that TD-DCS performance strongly depends on the system IRF. Among Gaussian pulse shapes, ∼300 ps pulse length appears to offer the best performance, at wide gates (500 ps and larger) with start times 400 and 600 ps after the peak of the TPSF at 765 and 1064 nm, respectively, for a 1-s integration time at photon detection rates seen experimentally (600 kcps at 765 nm and 4 Mcps at 1064 nm). Conclusions: Our work shows that optimal time gates satisfy competing requirements for sufficient sensitivity and sufficient SNR. The achievable performance is further impacted by system IRF with ∼300 ps quasi-Gaussian pulse obtained using electro-optic laser shaping providing the best results.

Significance: Single-molecule localization-based super-resolution microscopy has enabled the imaging of microscopic objects beyond the diffraction limit. However, this technique is limited by the requirements of imaging an extremely large number of frames of biological samples to generate a super-resolution image, thus requiring a longer acquisition time. Additionally, the processing of such a large image sequence leads to longer data processing time. Therefore, accelerating image acquisition and processing in single-molecule localization microscopy (SMLM) has been of perennial interest. Aim: To accelerate three-dimensional (3D) SMLM imaging by leveraging a computational approach without compromising the resolution. Approach: We used blind sparse inpainting to reconstruct high-density 3D images from low-density ones. The low-density images are generated using much fewer frames than usually needed, thus requiring a shorter acquisition and processing time. Therefore, our technique will accelerate 3D SMLM without changing the existing standard SMLM hardware system and labeling protocol. Results: The performance of the blind sparse inpainting was evaluated on both simulation and experimental datasets. Superior reconstruction results of 3D SMLM images using up to 10-fold fewer frames in simulation and up to 50-fold fewer frames in experimental data were achieved. Conclusions: We demonstrate the feasibility of fast 3D SMLM imaging leveraging a computational approach to reduce the number of acquired frames. We anticipate our technique will enable future real-time live-cell 3D imaging to investigate complex nanoscopic biological structures and their functions.

Namen te diplomske naloge je raziskati in pokazati kolikšni so lahko cenovni prihranki tiskanja, kako lahko privarčujemo pri papirju, ter kako s smotrnim tiskanjem obvarujemo okolje. Vsako podjetje ima npr. točno evidentirane avtomobile, nadzorujejo njihovo porabo in prevožene kilometre in v splošnem poskušajo stroške čim bolj optimizirati, vendar se velikokrat pozabi na »skrite« potrošnike, ki pa so vsem na očeh – tiskalniki oziroma multifunkcijske naprave. Ker imamo v Sloveniji zelo veliko samostojnih podjetnikov in malih podjetij je ta diplomska naloga usmerjena v raziskavo optimizacije tiskanja v malem podjetju, podjetju Promo.fil d.o.o. Stroški tiskanja imajo pogosto v strukturi celotnih stroškov podjetja nezanemarljiv delež, zato je smiselno tej problematiki posvetiti več pozornosti. V diplomski nalogi smo raziskali, kakšni so dejanski stroški tiskanja z laserskim tiskalnikom, ki je trenutno v uporabi v podjetju Promo.fil d.o.o., ter opravili analizo stroškov tiskanja na več različnih laserskih in brizgalnih večfunkcijskih napravah. Na podlagi opravljene analize smo izbrali najugodnejšo varianto. Pri tem smo poleg stroškovnih vidikov posvetili pozornost tudi vplivom na okolje. The purpose of this thesis is to investigate and show how much money can we save with printing, how can we save on paper, and how can we protect the environment with smart and economical printing. Each company has for example accurately recorded cars, control their consumption and mileage, and generally trying to optimize costs as much as possible, but they often forget about the "hidden" consumers, who are all in the eye - printers and multifunction devices. Since Slovenia has a lot of entrepreneurs and small businesses, this thesis focused on the research to optimize printing in a small company, the company Promo.fil d.o.o. Printing costs are often of total company costs not negligible proportion, so it makes sense to this issue more attention. In this thesis, we studied what are the actual cost of printing with a laser printer, which is currently in use in the company Promo.fil d.o.o., and conducted an analysis of the costs of printing on a variety of laser and inkjet devices. Based on the analysis, we chose the best variant. In this context, in addition to cost considerations devote attention to the impact on the environment.

There has been a growing interest in laser cleaning applications for a variety of organic materials such as paper, parchment, textiles, and leather during the last decade. However, archaeological organic materials, notably papyrus, have rarely been investigated. This contribution examines whether removal of burial encrustation can be justified in view of its short-term and long-term effects on the substrate. To examine this, tests using mock objects have been performed. Using artificially soiled and archaeological papyrus samples, optimization of laser cleaning parameters using a picosecond laser (1064 nm, various operating conditions) was attempted. Optimization was based on colorimetry, optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and cellulose degree of polymerization data, both before and after accelerated degradation. In papyrus, there is no clear damage threshold, and substrate degradation can always be observed and is comparable in treated (cleaned) and untreated (soiled) objects. Therefore, the decision on whether to clean papyrus using lasers is predominantly based on aesthetic and treatability (e.g. need for consolidation) criteria.

In this paper, we introduce two powerful graph reductions for the maximum weighted stable set (mwss) in general graphs. We show that these reductions allow to reduce the mwss in claw-free graphs to the mwss in a class of quasi-line graphs, that we call bipolar-free. For this latter class, we provide a new algorithmic decomposition theorem running in polynomial time. We then exploit this decomposition result and our reduction tools again to transform the problem to either a single matching problem or a longest path computation in an acyclic auxiliary graph (in this latter part we use some results of Pulleyblank and Shepherd [10]). Putting all the pieces together, the main contribution of this paper is a new polynomial time algorithm for the mwss in claw-free graphs. A rough analysis of the complexity of this algorithm gives a time bound of O(n6), where n is the number of vertices in the graph, and which we hope can be improved by a finer analysis. Incidentally, we prove that the mwss problem can be solved efficiently for any class of graphs that admits a "suitable" decomposition into pieces where the mwss is easy.

Bu çalışmada kağıt üretimi sırasında ortaya çıkan ve karmaşık bir bileşime sahip olan atıksuyun elektrokimyasal yöntemler uygulanarak arıtımı hedeflenmiştir. Kağıt endüstrisi birim ürün başına kullandığı aşırı su ve ürettiği atıksuda bulunan biyolojik olarak parçalanamayan kimyasalları ile çevresel etkisi en güçlü proseslerden birisidir.Kağıt endüstrisine ait atıksuların kimyasal oksijen ihtiyacı (200-2000 mg/L) ve biyolojik oksijen ihtiyacı (100-1000 mg/L) değerleri çok yüksektir. Bu nedenle alıcı ortama deşarjı verimli bir arıtımdan sonra olmalıdır. Literatürde farklı endüstrilerin atıksuları için yapılmış elektrokimyasal çalışmalar mevcuttur. Bu çalışma kağıt endüstrisine yönelik yapılmış ilk çalışmadır. Gerçekleştirilen ön deneylerle elektrot türüne karar verildikten sonra Design Expert 6.0 programıyla deneysel optimizasyon yapılmış ve optimum koşullarda reaksiyon kinetiği incelenmiştir.Deneylerde elektrolit olarak daha önceki çalışmalarda kullanılan ve yüksek bir iletkenliğe sahip olan NaCl kullanılmış ve yüksek arıtım verimi ve düşük maliyeti nedeniyle elektrot türü olarak demir seçilmiştir. Kirlilik yükü, elektrolit derişimi ve potansiyel fark sistemin bağımsız değişkenleri olarak belirlenmiş ve bunlara karşılık KOİ giderimi, arıtılan KOİ miktarı, KOİ giderimi ilk hızı, verim, bulanıklık giderimi ve çökelek miktarı tespit edilmiştir. Bağımsız değişkenler Design-Expert 6.0 programına tanıtıldıktan sonra deneysel planlama yapılmış ve tasarlanan deneyler Cevap Yüzey Yöntemi (CYY) kullanılarak optimize edilmiştir.Deneyler sonucunda KOİ gideriminin % 41.12 - % 65.71, arıtılan KOİ miktarının 128.8 mg/L ? 476 mg/L, KOİ giderimi ilk hızının 100.8 mgKOİ/L.h ? 705.6 mgKOİ/L.h, verimin 1.3 kgKOİ/kWh ? 86.8 kgKOİ/kWh, bulanıklık gideriminin % 80.72 - %89.79 ve çökelek miktarının % 3 - %18 aralıklarında değiştiği görülmüştür.Optimizasyon sırasında elektrolit derişimi minimum değerde, kirlilik yükü maksimum değerde ve potansiyel fark programın belirlediği aralıkta tutulmuştur. Buna karşılık % KOİ gideriminin, KOİ giderimi ilk hızının, verimin, bulanıklık gideriminin ve arıtılan KOİ miktarının maksimum, çökelek miktarının ise minimum olması tercih edilmiştir. Optimum koşulların 9.97V potansiyel fark altında % 85.81 'lik kirlilik yüküne sahip atıksuya 5.07 g/L elektrolit eklenmesi ile sağlandığı belirlenmiştir ve bu koşullarda yapılan test deneyinde % 48.94 KOİ giderimi, 386.40 mg/L arıtılan KOİ miktarı, 492.8 mgKOİ/L.h KOİ giderimi ilk hızı, 8.25 kgKOİ/kWh verim, %82.75 bulanıklık giderimi ve %10 çökelek miktarı tespit edilmiştir. Kinetik çalışmalar sonucunda reaksiyon derecesi 1.5, reaksiyon hız sabiti 0.00125 mg(-0.5)/L(-0.5)-dak ve aktivasyon enerjisi 10.860 kj/mol olarak saptanmıştır.Elde edilen sonuçlar literatür için orijinal bir katkı sağlamakla beraber elektrokimyasal arıtımın kağıt sanayi atıksuyuna uygulanabilecek alternatif bir yöntem olduğunu göstermektedir. In this study electrochemical treatment of the wastewater which is produced in paper industry and which has a complex composition is aimed. Paper industry has a powerful effect on environment with its high amount of water usage per unit product and its wastewater contains chemicals which can not be decomposed biologically. Chemical oxygen demand (200-2000 mg/L) and biological oxygen demand (100-1000 mg/L) of the wastewater in the paper industry have high values and therefore its discharge into receiving waterways must be made after an efficient treatment. There are some electrochemical studies for different industries however this is the first study aimed at paper industry. In the preliminary studies first the electrode type was determined and then experimental optimization was executed. Reaction kinetic was examined at the optimum conditions.Throughout the experiments NaCl which was used in the prior studies and having a high conductivity was used as electrolyte. Iron was selected as electrode with its high treatment efficiency and low cost. Independent variables of the system were determined as loading rate, electrolyte concentration and potential difference. In response to these, COD removal, treated COD amount, initial COD removal rate, efficiency, turbidity removal and precipitate amount were determined. After the independent variables were introduced into Design-Expert 6.0 program, experimental planning was created and then proposed experiments ware optimized with surface response method.After the experiments it was seen that the range of the COD removal, treated COD amount, initial COD removal rate, efficiency, turbidity removal and precipitate amount changes between 41.12% - 65.71%, 128.8 mg/l ? 476 mg/l, 100.8 mgCOD/L.h ? 705.6 mgCOD/L.h, 1.3 kgCOD/kWh ? 86.8 kgCOD/kWh, 80.72% - 89.79% and 3% - 18%, respectively.During the optimization, electrolyte concentration was fixed at its minimum value and loading rate was fixed at its maximum value. Potential difference was kept in the range determined by the program. On the other hand, COD removal, treated COD amount, initial COD removal rate, energy efficiency and turbidity removal were maximized and precipitate amount was minimized. Optimum conditions were accomplished with a loading rate of 85.81 %, electrolyte concentration of 5.07 g/L and potential difference of 9.97 V. It was seen that test experiment performed at these conditions produced 48.94 % COD removal, 386.40 mg/L treated COD amount, 492.8 mgCOD/L.h initial COD removal rate, 8.25 kgCOD/kWh efficiency, 82.75% turbidity removal and 10% precipitate amount. After the kinetic studies were completed, reaction order was determined as 1.5, reaction rate constant was determined as 0.00125 mg(-0.5)/L(-0.5)-min and activation energy was determined as 10.860 kj/mol.In addition to its original contribution to literature, results of this study show that electrochemical treatment can be applied to wastewater of the paper industry as an alternative method. 137

Purified alkali stable xylanase from Aspergillus fischeri was immobilized on polystyrene beads using diazotization method. An expanded bed bioreactor was developed with these immobilized beads to biobleach the paper pulp in continuous mode. Response surface methodology was applied to optimize the biobleaching conditions. Temperature (�C), flow rate of pulp (ml/min) and concentration of the pulp (%) were selected as variables in this study. Optimal conditions for biobleaching process were reaction temperature 60 �C, flow rate of 2 ml/min and 5% (w/v) of pulp. The kappa number reduced from 66 in the unbleached pulp to 20 (reduction of 87%). This system proves to be a better option for the conventional chlorine based pulp bleaching. � 2008 Elsevier Ltd. All rights reserved.