Silicon: quantum dot photovoltage triodes

Silicon is widespread in modern electronics, but its electronic bandgap prevents the detection of infrared radiation at wavelengths above 1,100 nanometers, which limits its applications in multiple fields such as night vision, health monitoring and space navigation systems. It is therefore of interest to integrate silicon with infrared-sensitive materials to broaden its detection wavelength. Here we demonstrate a photovoltage triode that can use silicon as the emitter but is also sensitive to infrared spectra owing to the heterointegrated quantum dot light absorber. The photovoltage generated at the quantum dot base region, attracting holes from silicon, leads to high responsivity (exceeding 410 A·W−1 with Vbias of −1.5 V), and a widely self-tunable spectral response. Our device has the maximal specific detectivity (4.73 × 1013 Jones with Vbias of −0.4 V) at 1,550 nm among the infrared sensitized silicon detectors, which opens a new path towards infrared and visible imaging in one chip with silicon technology compatibility.

Tomographic PIV investigation of vortex shedding topology for a cantilevered circular cylinder

The wake of a finite wall-mounted circular cylinder of diameter $D$ and height $H$ is investigated for aspect ratios $3\leq H/D \leq 7$ and boundary layer thickness of $\delta /D \approx 0.98$ using tomographic particle image velocimetry. The Reynolds number based on $D$ is $Re = 750$ . The mean wake topology is related to the evolution of the periodically shed vortices, educed from a low-order representation based on proper orthogonal decomposition of the three-dimensional velocity field. The main topological features are an arch vortex, defining the recirculating base region, and a quadrupole structure consisting of two pairs of opposite-sign vorticity concentrations extending downstream behind the obstacle-free end and wall junction. The quadrupole is the time-averaged signature of shed vortices. Vortex-tilting terms in the base region act to reorient flow-normal vorticity components streamwise, resulting in the reorientation of the ends of vortices initially shed parallel to the cylinder side walls. Through the action of the vortex-stretching terms, the bent ends connect successive vortices in a continuous chain. The influence of $H/D$ on the development of the quadrupole is characterized. The results demonstrate that the quadrupole in the mean field emerges as an imprint of the shed full-loop structures. This work reconciles mean and instantaneous interpretations satisfying the solenoidal condition on the vorticity field.

Endonasal Endoscopic Approach to Sphenoid Sinus Lesion

Background: Anatomical position of sphenoid sinus, sellar and parasellar regions are located in the skull base having difficulty to approach due to presence of vital structures in its proximity. The presence of carotid artery and optic nerve in its lateral wall make the situation difficult due to lack of illumination and visual limitation. In the past traditional techniques to approach this region like external ethmoidectomy, transseptal transsphenoidal routes were used causing significant trauma, bleeding and risk of possible complication in skull base region. Aim: to access the efficacy and safety of the endonasal endoscopic approach to the sphenoid sinus Method: This study was done in the department of ENT Shaikh Zayed hospital Lahore, 33 patients who were diagnosed to have lesions involving sphenoid sinus. Detailed history, thorough ENT examination, relative investigations were done and all were managed naso-endoscopically. Results: The review of these cases showed that the endoscopic technique was found to have the advantages of being minimally invasive with no external incisions. There is less trauma to the patient, no need for operating microscope or intraoperative image intensifier. Conclusion: The conclusion of our study showed that naso-endoscopes are excellent tools for better visualization due to availability of different angled scopes and good illumination. The disease is better assessed and cleared identifying landmarks with quicker postoperative recovery and lesser overall morbidity. Over the last few years, endoscopic approach to these regions has gained much popularity because of advances in optics, endoscopes and illumination. Keywords: Endoscopic sinus surgery, sphenoid sinus

Education problems for sustainable development in the focus of assessment of the demographic situation in the region (on the example of the Novosibirsk region of the Russian Federation)

The main purpose of this study is to study the problems of modern education through the prism of the regional demographic situation in the context of the implementation of sustainable development. The base region is the Novosibirsk region, on the territory of which a regional education system has developed, which is characterized by a high susceptibility to innovations. The main resource that ensures effective regional development is human capital. In this regard, it is relevant to study not only the problems of education development, taking into account the implementation of sustainable development, but also the characteristics of the demographic situation as a factor of sustainable development. The article reveals the features of the problem of education development in the interests of sustainable development, provides a meaningful analysis of the SD concept, highlights the main stages of its formation, which make up SD components; education is considered as a key component of the SD concept, the main conditions of transformations in the education system are highlighted, an assessment of demographic parameters is given, according to which it is possible to predict education processes both at the regional and global levels.

Estimating the optical extinction of liquid water clouds in the cloud base region

Accurate lidar-based measurements of cloud optical extinction, even though perhaps limited to the cloud base region, are useful. Arguably, more advanced lidar techniques (e.g. Raman) should be applied for this purpose. However, simpler polarisation and backscatter lidars offer a number of practical advantages (e.g. better resolution and more continuous and numerous time series). In this paper, we present a backscatter lidar signal inversion method for the retrieval of the cloud optical extinction in the cloud base region. Though a numerically stable method for inverting lidar signals using a far-end boundary value solution has been demonstrated earlier and may be considered as being well established (i.e. the Klett inversion), the application to high-extinction clouds remains problematic. This is due to the inhomogeneous nature of real clouds, the finite range resolution of many practical lidar systems, and multiple scattering effects. We use an inversion scheme, where a backscatter lidar signal is inverted based on the estimated value of cloud extinction at the far end of the cloud, and apply a correction for multiple scattering within the cloud and a range resolution correction. By applying our technique to the inversion of synthetic lidar data, we show that, for a retrieval of up to 90 m from the cloud base, it is possible to obtain the cloud optical extinction within the cloud with an error better than 5 %. In relative terms, the accuracy of the method is smaller at the cloud base but improves with the range within the cloud until 45 m and deteriorates slightly until reaching 90 m from the cloud base.

Unusual Presentation of Feline Leprosy Caused by Mycobacterium lepraemurium in the Alpine Region

A 9-year-old cat was referred with multiple, raised, ulcerative and non-ulcerative nodules in the periocular area, sclera and ear-base region, and on the ventral aspect of the tongue. In addition, a progressive ulcerative skin nodule on the tail was observed. Fine-needle aspirations of multiple nodules from the eyelid and sclera revealed the presence of histiocytes with numerous acid-fast intracellular bacilli. The replication of slowly growing mycobacteria in liquid media was detected from biopsied nodules after three months of incubation. The molecular characterization of the isolate identified Mycobacterium (M.) lepraemurium as the cause of the infection. The cat was treated with a combination of surgical excision and a four-week course of antimicrobial therapy including rifampicin combined with clarithromycin. This is an unusual manifestation of feline leprosy and the first molecularly confirmed M. lepraemurium infection in a cat with ocular involvement in Europe. The successful combination of a surgical and antimycobacterial treatment regimen is reported.

Estimating optical extinction of liquid water clouds in the cloud base region

Accurate lidar-based measurements of cloud optical extinction, even though perhaps limited to the cloud base region, are useful. Arguably, more advanced lidar techniques (e.g. Raman) should be applied for this purpose. However, simpler polarization and backscatter lidars offer a number of practical advantages (e.g. better resolution, more continuous and numerous time series). In this paper we present a backscatter lidar signal inversion method for the retrieval of the cloud optical extinction in the cloud base region. Though a numerically stable method for inverting lidar signals using a far-end boundary value solution has been earlier demonstrated and may be considered well-established (i.e. the Klett inversion), the application to high-extinction clouds remains problematic. This is due to the inhomogeneous nature of real clouds, the finite range-resolution of many practical lidar systems and multiple-scattering effects. We use an inversion scheme where a backscatter lidar signal is inverted based on the estimated value of cloud extinction at the far end of the cloud and apply a correction for multiple-scattering within the cloud and a range resolution correction. By applying our technique to the inversion of synthetic lidar data, we show that for a retrieval of up to 90 m from the cloud base it is possible to obtain the cloud optical extinction within the cloud with an error better than 5 %. In relative terms, the accuracy of the method is smaller at the cloud base but improves with the range within the cloud until 45 m and deteriorates slightly until reaching 90 m from the cloud base.

Analysis of base characteristics of trench gate field termination IGBT

Trench gate structure represents the latest structure of Insulated Gate Bipolar Transistor(IGBT). Because there are great differences in model analysis coordinate system and carrier transport between trench gate structure and planar gate structure, the modeling method using planar gate structure will inevitably have great deviation. Based on the characteristics of trench gate structure and model analysis coordinate system, the base region is divided into PNP and PIN by considering the two-dimensional effect of carriers. According to whether the trench of PIN part can be covered by depletion layer of PNP part, the specific base region current is analyzed. Finally, simulation and experimental verification are carried out.

Anatomy Variation of Ruptured Anterior Communicating Artery (AcoA) Aneurysm : Serial Cases

Introduction : Intracranial aneurysms (IA) is an acquired disease characterized by dilatation of intracranial arteries, and is usually found at the location of arterial branches in the cranii base region. The selection of management and anatomic variations is quite interesting to be discussed in the case of aneurysms. Cases Report : Four cases of AcoA aneurysm were reported with variations in clinical manifestations, A1 segment anatomy, fundal projections and management considerations (Coiling vs. Clipping). This case series illustrates the compatibility with previous case studies that have existed. Discussion : The author concludes that the actions taken in cases I, II and III are in the form of coiling due to age, dome and neck ratio and access to perform such difficult surgical procedures. In case IV , it was considered to be performed surgical clipping action due to the presence of intracerebal hemoraghic, and the approach can be done from a non dominant hemisphere, proximal control only through the right carotid and the location of the posterior dome which was favorable for surgical clipping Conclusion : Aneurysms from the ACA-anterior communicating artery (ACoA) complex are some of the most complex lesions in the field of vascular neurosurgery. This location is where most rupture aneurysms occured with high mortalities due to complications of vasospasm and SAH. The choice of management in aneurysm cases which involved many factors such as age and anatomic variations.