Ultrafast dynamics in the presence of antiferromagnetic correlations in electron-doped cuprate La2−x_{2-x}Cex_xCuO4±δ_{4\pm\delta}

We used femtosecond optical pump-probe spectroscopy to study the photoinduced change in reflectivity of thin films of the electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$ (LCCO) with dopings of x$=$0.08 (underdoped) and x$=$0.11 (optimally doped). Above T$_c$, we observe fluence-dependent relaxation rates which onset at a similar temperature that transport measurements first see signatures of antiferromagnetic correlations. Upon suppressing superconductivity with a magnetic field, it is found that the fluence and temperature dependence of relaxation rates is consistent with bimolecular recombination of electrons and holes across a gap (2$\Delta_{AF}$) originating from antiferromagnetic correlations which comprise the pseudogap in electron-doped cuprates. This can be used to learn about coupling between electrons and high-energy ($\omega>2\Delta_{AF}$) excitations in these compounds and set limits on the timescales on which antiferromagnetic correlations are static

Power quality improvement using ultra capacitor based dynamic voltage restorer with real twisting sliding mode control

Introduction. Power quality is a major problem in today's power system, since it may have an impact on customers and utilities. Problem. Power quality is important issue of financial consequences for utilities, their consumers and load apparatus vendors. Voltage sag/swell are the most significant and usually occurring power quality issues in a secondary distribution system for sensitive loads. Goal. Dynamic voltage restorer is a fast, flexible, effective and dynamic custom power device can be used to compensate voltage sag/swell with integration of energy storage. Ultra capacitors have ideal properties of great power density and low energy density for elimination of voltage sag/swell. Their performance is mostly determined by the control strategy established for switching of voltage source converters. Originality. In this research, a strategy for the voltage source converter of dynamic voltage restorer based on the real twisting sliding mode control and ultra capacitor is developed to correct the fault that successfully eliminates the impacts of voltage sag/swell. Methodology. Ultra capacitor along with real twisting sliding mode control gives the more robustness and faster response, with also increasing the compensation time of the dynamic voltage restorer. Testing environment. To evaluate the performance of the proposed control approach, the MATLAB / Simulink SimPower System tool box is employed. Practical values. According to Simulation results clearly shows that the ultra capacitor along with real twisting sliding mode control effectively eliminate the voltage sag/swell in a very short time of 2 ms as compared to IEEE standards that is 20 ms, with less than 5 % total harmonic distortion for sensitive loads as per Information Technology Industry Council Curve and SEMI-F-47 Standards.Вступ. Якість електроенергії являє собою серйозну проблему в сучасній енергосистемі, оскільки вона може впливати на споживачів та комунальні служби. Проблема. Якість електроенергії є важливим питанням з точки хору фінансових наслідків для комунальних підприємств, їх споживачів та постачальників апаратури-навантажень. Провали/стрибки напруги є найбільш серйозними проблемами з огляду на якість електроенергії, які зазвичай виникають у вторинній системі розподілу для чутливих навантажень. Мета. Динамічний відновник напруги — це швидкий, гнучкий, ефективний і динамічний пристрій живлення, який можна використовувати для компенсації провалів/стрибків напруги за допомогою інтеграції накопичувача енергії. Суперконденсатори мають ідеальні властивості високої щільності потужності та низької щільності енергії для усунення провалів/стрибків напруги. Їх ефективність переважно визначається стратегією управління, встановленої для комутації перетворювачів джерел напруги. Оригінальність. У цьому дослідженні розроблено стратегію для перетворювача джерела напруги динамічного відновника напруги на основі керування реальним ковзним режимом скручування та суперконденсатора для виправлення несправності, яка успішно усуває наслідки провалу/стрибка напруги. Методологія. Суперконденсатор разом із керуванням реальним ковзним режимом скручування забезпечує більшу надійність та швидшу реакцію, а також збільшує час компенсації динамічного відновника напруги. Середовище для тестування. Для оцінки ефективності запропонованого підходу до управління використовується комплекс програмного забезпечення MATLAB/Simulink SimPower System. Практична цінність. Згідно з результатами моделювання ясно видно, що суперконденсатор разом з керуванням реальним ковзним режимом скручування ефективно усувають провали/стрибки напруги за дуже короткий час 2 мс у порівнянні зі стандартами IEEE, у відповідності до яких він становить 20 мс, із загальним спотворенням гармонік менше 5 % для чутливого навантаження відповідно зі стандартами Information Technology Industry Council Curve та SEMI-F-47

Secondary Fahr’s Disease: A Consequence of Post-Thyroidectomy Hypoparathyroidism

Objective: The objective of this case report is to emphasize the importance of considering uncommon conditions like Fahr’s disease in the differential diagnosis of seizures and cognitive impairment, especially in patients with a history of thyroidectomy. Material and Methods: A 56-year-old woman who had undergone subtotal thyroidectomy 25 years previously presented with movement disorder and cognitive impairment secondary to hypoparathyroidism. A CT scan of the brain showed pathognomonic bilateral calcification in the basal ganglia, thalamus and cerebellar nuclei. Result: The patient was diagnosed with Fahr’s disease caused by post-thyroidectomy hypoparathyroidism and successfully managed with oral calcium, carbidopa/levodopa and haloperidol. Conclusion: We recommend the routine use of CT scanning in the long-term follow-up of post-thyroidectomy patients

Purification and characterization of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. G1

A cyclodextrin glucanotransferase (CGTase) was successively purified by ammonium sulphate precipitation, and affinity chromatography on a-CD (epoxy)-Sepharose 6B column. The specific activity of the CGTase was increased approximately 2200-fold, from 8.43 U/mg protein to 18,866 U/mg protein. SDS-PAGE showed that the purified CGTase was homogeneous and the molecular weight of the purified CGTase was about 75 kDa. The molecular weight of the enzyme that was estimated by gel filtration under native condition was 79 kDa. This has indicated that Bacillus sp. G1 CGTase is a monomeric protein. The isoelectric point (pI) of the enzyme was about 8.8. Characterization of the enzyme exhibited optimum pH and temperature of 6.0 and 60 8C, respectively. The enzyme was stable from pH 7.0 to 9.0 and retained its high activity up to 60 8C. However, in the presence of 20 mM Ca2+, the purified CGTase is able to prolong its thermal stability up to 70 8C. CGTase was strongly inhibited by ZnSO4, CuSO4, CoCl2, FeSO4, FeCl3 and EDTA. Km and Vmax for the purified enzyme were 0.15 mg/ml and 60.39 mg bcyclodextrin/( ml min), respectively, with soluble starch as substrate. In cyclodextrin production, tapioca starch was found to be the best substrate used to produce CDs. The enzyme produced g- and b-CD in the ratio of 0.11:0.89 after 24 h incubation at 60 8C, without the presence of any selective agents

Deep Depth From Focus

Depth from focus (DFF) is one of the classical ill-posed inverse problems in computer vision. Most approaches recover the depth at each pixel based on the focal setting which exhibits maximal sharpness. Yet, it is not obvious how to reliably estimate the sharpness level, particularly in low-textured areas. In this paper, we propose `Deep Depth From Focus (DDFF)' as the first end-to-end learning approach to this problem. One of the main challenges we face is the hunger for data of deep neural networks. In order to obtain a significant amount of focal stacks with corresponding groundtruth depth, we propose to leverage a light-field camera with a co-calibrated RGB-D sensor. This allows us to digitally create focal stacks of varying sizes. Compared to existing benchmarks our dataset is 25 times larger, enabling the use of machine learning for this inverse problem. We compare our results with state-of-the-art DFF methods and we also analyze the effect of several key deep architectural components. These experiments show that our proposed method `DDFFNet' achieves state-of-the-art performance in all scenes, reducing depth error by more than 75% compared to the classical DFF methods.Comment: accepted to Asian Conference on Computer Vision (ACCV) 201

Occurrence, diversity and morphology of poroid wood decay by Ganoderma spp. from tropical moist deciduous forest region of Bangladesh

There are many hot spots in tropical moist deciduous forest region where wood decay fungi grow naturally. An investigation was carried  out  to  collect, identify  and  preserve wood decay Ganoderma spp. on the basis of morphological characteristics  from Pabna,  Dhaka and  Rajshahi under tropical  moist deciduous  forest  region in Bangladesh during  June  to September  2016 and July to October  2017. This study was conducted to  record the  morphological  variability,  distribution,  habitat  and diversity of  the Ganoderma  population. A  total  of  40 Ganoderma  samples  were  collected  and identified to nine species  under  Ganodermataceae family.  The samples were collected from the sites by walking through the area following standard method. The field data and laboratory analytical data was recorded during sample collection and in the laboratory, respectively.The highest density of occurrence (23%) was recorded for Ganoderma lucidum and Ganoderma oregonense followed by Ganoderma applanatum (20%), Ganoderma praelongum (19%), Ganoderma lesklokorka (18.5%), Ganoderma pfeifferi (17%), Ganoderma boninense (15%), Ganoderma lipsiense (13%) and Ganoderma tsugae (11%). The highest frequency of occurrence (10%) was recorded for Ganoderma applanatum and Ganoderma oregonense followed by Ganoderma lucidum (9%), Ganoderma pfeifferi (8%), Ganoderma boninense (8%), Ganoderma praelongum (7%), Ganoderma lesklokorka (7%),Ganoderma tsugae (6%) and  Ganoderma lipsiense (5%). During survey, Koroi (Albizia procera), Aurjun (Terminalia arjuna), Sisso plant (Dalbergia sissoo), Neem (Azadirachta indica), Golden shower (Acacia auriculiformis) and Rain tree (Albizia lebbeck) were found as hosts of Ganoderma spp. The specimens were preserved in the SAU Herbarium of Macro Fungi (SHMF) and might be useful in mushroom breeding and development program for medicine and food industry sector in future