Using nonlinear ring resonators for designing an all optical comparator

An all optical comparator is designed based on photonic crystals. The proposed structure was designed based on optical threshold switching that is realized using three nonlinear ring resonators. All nonlinear rings have the same optical characteristics, such that they can drop low intensity (as low as 0.5 W/μm2) optical waves at 1550 nm, but cannot drop the optical waves with optical intensity of 1 W/μm2. For the proposed structure the rise and fall time are about 2 and 1 ps, respectively. Therefore the bit rate is about 167 GHz and the ON/OFF contrast ratios for O1, O2, and O3 are 13.5, 13.6, and 13.3 dB, respectively.

Repurposing of Dapsone as Neuroprotective Agent on Cuprizone-induced Demyelination via Targeting Nrf2 and NF-kB in C57BL/6 Mice

Multiple Sclerosis (MS) is an inflammatory disorder wherein the myelin of nerve cells in central nervous system is damaged. Fatigue, lack of coordination, blurred vision and mental problems are some of the symptoms of MS. In the current study, we assessed the performance of Dapsone (DAP) on improvement of behavioral dysfunction and preservation of myelin in the cuprizone (CPZ) induced demyelination model via targeting Nrf2 and IKB. MS was induced in C57BL/6 mice through diet supplementation of CPZ (0.2%) for 6 weeks and DAP (12.5 mg/kg/day; i.p.) was administered once daily for the last 2 weeks of treatment. Behavioral tests (pole test and rotarod performance test), LFB and H&E staining and Immunohistochemistry (IHC) staining of p-Nrf2 and p-IKB were performed to evaluate locomotor coordination, observe the area of demyelination in corpus callosum respectively. Furthermore, superoxide dismutase (SOD), and nitrite were measured. Based on the results of the weight of mice, it was shown that the weight of the groups receiving CPZ decreased compared to the control group (P < 0.001), while administration of dapsone increased the weight (P < 0.001). Pole test showed that CPZ increased latency time to fall (P <0.01) but the latency to reach the floor in DAP-CPZ group was significantly shorter than the CPZ group (P <0.001). Rotarod performance test showed the effect of CPZ in reducing fall time in CPZ group (P <0.01) however treatment with DAP significantly increased fall time (P < 0.001). In LFB staining increased demyelination was seen in the CPZ group and decreased demyelination was observed in the DAP group. IHC staining results of p-Nrf2 and p-IKB showed that CPZ significantly decreased p-Nrf2 and elevated p-IKB levels compared with the control group (P <0.001), but in DAP -treated groups markedly modified these changes (P < 0.001). CPZ feeding led to increase of brain nitrite levels and reduced SOD activity (P <0.05) but in DAP-treated considerably reversed CPZ-induced changes in nitrite and SOD activity level (P <0.001). These data support the suggestion that the beneficial properties of dapsone on the CPZ-induced demyelination are mediated by targeting Nrf2 and NF-kB pathways.

Effects of External Auditory Meatus Occlusion on Ocular Vestibular Evoked Myogenic Potentials Induced by Bone Conducted Sound

To facilitate more reliable recordings of the ocular vestibular evoked myogenic potentials (oVEMP) induced by bone-conducted sound using the B81 bone conduction transducer, we preliminarily studied the effects of external auditory meatus occlusion using an earplug on such oVEMP. Eight healthy volunteers (four males and four females, 26–48 years of age, mean age: 34. 5 years) and 14 patients with vestibular disease (2 males and 12 females, 18–59 years of age, mean age: 41.5 years) were enrolled. oVEMP testing was performed using a B81 placed on the temple. Tone bursts (500 Hz, rise/fall time: 2 ms, plateau time: 2 ms, and 70 dB nHL) were presented at a rate of 5.1 Hz. N1-P1 amplitudes were measured and analyzed. Occlusion resulted in significantly larger N1-P1 amplitudes [mean ± SE (SD): 12.3 ± 1.67 (6.71) μV vs. 9.55 ± 1.55 (6.21) μV; p = 0.020, paired t-test]. While four patients did not exhibit any response on either side in the absence of occlusion, all of them showed unilateral or bilateral responses when occlusion was employed. In any patient occlusion did not result in loss of oVEMP responses. External auditory meatus occlusion using an earplug could allow more reliable recordings of bone conduction transducer-induced oVEMP.

THEORETICAL STUDIES OF THE TECHNOLOGICAL PROCESS OF OPERATION OF A COULTER WITH A SEED VELOCITY SUPPRESSOR FOR PLANTING GRAIN CROPS

Рассматривается решение одной из важнейших проблем при посеве зерновых культур – равномерность распределения семян по длине и глубине борозды, при исключении забивания выходного отверстия семяпровода. Приведены теоретические исследования сошника с гасителем скорости семян для посева зерновых культур, а также описана конструкция разработанного сошника. Отмечен ряд существенных недостатков современных сошников зерновых сеялок. В результате теоретических исследований составлены уравнения для определения времени движения семени, расстояние между центрами масс от первого удара до второго, скорость семени при падении, время падения семени при выходе из семяпровода, уравнение движения семени при выходе его из семяпровода, а также получены значения выше указанных значений, которые обеспечат повышение качества работы сошника, что скажется на повышении равномерности распределения семян по длине рядка и урожайности зерновых культур. In the article, one of the major issues of planting crops is considered. It is the problem of the uniform distribution of the seeds along the length and depth of the furrow, when excluding the clogging of the outlet of the grain tube. Theoretical studies of a coulter with a seed velocity suppressor for planting grain crops are presented, and the design of the developed coulter is described. Several significant disadvantages of modern coulters of grain seeders are noted. As a result of theoretical studies, the equations to determine the movement time of a seed, the distance between the centres of mass from the first strike to the second one, the seed velocity in the fall, the fall time of a seed when leaving the grain tube, the equation of the seed motion at its leaving from the grain tube are composed. Moreover, the values of these equations are obtained, which ensure improved coulter quality. It can have an impact on increasing the uniformity of seed distribution over the length of the row and grain yields.

Characteristics of fall‐related head injury versus non‐head injury in the older adults

Background This study aimed to examine the characteristics of older adults patients who suffered a head injury after a ground-level fall in comparison to non-head injury patients as well as the factors associated with severity in those with head injury only. Methods Patients were classified into two groups, the head injury group and the non-head injury group. The characteristics were compared and factors associated with head injury were evaluated. Factors relating to severe injury in the head injury group were also investigated. Results The head injury group comprised 42 % of a study subjects. Male sex; fall time of 18:00–23:59; fall location of medical facility, transportation area, and public or commercial facility; fall in an outdoor area; fall during daily activity; alcohol ingestion; fall from stairs; non-slippery floor conditions; concrete flooring; sloped flooring; and presence of obstacles on the floor were risk factors for head injury in the older adults after a ground-level fall. Male sex and age over 70 years; fall time of 00:00–05:59; fall in a residential facility; fall in an indoor area; fall during daily activity; fall from stairs; non-slippery floor conditions; and presence of obstacles on the floor were factors associated with severe injury in the head injury group. Conclusions Male sex with advanced age, indoor fall, and the presence of obstacles on the floor were risk factors for severe injury in the head injury group in older adults individuals who suffered a ground-level fall. It is necessary to develop appropriate ground-level fall prevention programs by evaluating the individual and environmental characteristics of older adults patients.

The Future of Plunger Lift Control Using Artificial Intelligence

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201132, “The Future of Plunger Lift Control Using Artificial Intelligence,” by Ferdinand Hingerl and Brian Arnst, SPE, Ambyint, and David Cosby, SPE, Shale Tec, et al., prepared for the 2020 SPE Virtual Artificial Lift Conference and Exhibition - Americas, 10-12 November. The paper has not been peer reviewed. Dozens of plunger lift control algorithms have been developed to account for different well conditions and optimization protocols. However, challenges exist that prevent optimization at scale. To address these challenges, a plunger lift optimization software was developed. One aspect of this software is enabling set-point optimization at scale. This paper will present the methodology to do so, detailing three separate areas working in unison to offer significant value to plunger lift well operators. Introduction Even in vertical wells, plunger lift presents significant challenges to optimization. Despite their mechanical simplicity, plunger lifted wells produce large amounts of data, and the combinations of possible set points to optimize the well are many. Additionally, plunger lift wells can present a variety of different types of anomalies and problems that require a robust understanding of the underlying physics and mathematics. Such problems then are amplified when applied to horizontal well applications. The underlying physics and mathematics applied throughout the years for vertical wells do not produce accurate results for horizontal wells. Additionally, the anomalies produced in horizontal wells are more complex. Finally, typical production engineers and well optimizers now regularly look after more than 150—and often more than 500—wells, creating additional resource constraints to optimizing a field of plunger lift wells. The presented plunger lift optimization software was implemented by creating a secure connection between the operator’s supervisory control and data acquisition (SCADA) network and the cloud. As new data are generated by the SCADA network, they are automatically transmitted to the cloud and processed. Plunger Lift Control Algorithm Overview These algorithms are the software code that determines when the well opens and when the well closes. Even though the algorithms only control well open/close, the plunger moves through four stages of plunger operation to complete one cycle: plunger fall time, casing pressure build time, plunger rise, and after flow (or production). Optimizing each individual stage is critical to ideal well production. Plunger fall time is the time required for the plunger to descend from the lubricator to the bottomhole assembly (BHA). Currently, operators use the manufacturer’s anticipated fall time, trial and error, previous knowledge, acoustical plunger tracking, and plunger fall applications to set the appropriate fall time in the controller. A “fudge factor” is often applied to help ensure that the fall timer does not expire before the plunger reaches the BHA. Plunger fall time is affected by many changing variables: plunger condition, tubing condition, liquid height, and gas and liquid density. These variables make it difficult for a fall timer set once to represent accurately the correct time required for the plunger to reach the BHA on every cycle.