79 research outputs found

    Flat-tubular solid oxide fuel cells and stacks: a review

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    Solid oxide fuel cells (SOFCs) offer numerous advantages in terms of high efficiency and clean electrochemcial energy conversion devices. However, owing to high operation temperature, this technology is restricted to stationary applications and leads to components degradation and long-term stability issues. The development of new design and their modifications for improving the electrochemical performance at intermediate temperatures and durability of the SOFC components are very important to bring this technology one step closer to the market. In this context, the current research on the development, properties, performance, and stability of geometrically modified flat-tubular (FT) SOFC cell and the stack is reviewed in detail. This advanced design exhibits higher performance compared to the tubular type and longer stability in comparison to the planar type SOFCs. The application of the interconnect material is emerging as the key factor influencing the electrical output of the FT-SOFC and operation at high temperatures and current density are the critical issues for cell durability. New stack designs are discussed in detail and experimental findings are summarized

    Development of generic scheduling concepts for OpenGL ES 2.0

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    The ability of a Graphics Processing Unit (GPU) to do efficient and massively parallel computations makes it the choice for 3D graphic applications. It is been extensively used as a hardware accelerator to boost the performance of a single application like 3D games. However, due to increasing number of 3D rendering applications and the limiting resource constraints (especially on embedded platforms), such as cost and space, a single GPU needs to be shared between multiple concurrent applications (GPU multitasking). Especially for safety-relevant scenarios, like, e.g., automotive applications, certain Quality of Service (QoS) requirements, such as average frame rates and priorities, apply. In this work we analyze and discuss the requirements and concepts for the scheduling of 3D rendering commands. We therefore propose our Fine-Grained Semantics Driven Scheduling (FG-SDS) concept. Since existing GPUs cannot be preempted, the execution of GPU command blocks is selectively delayed depending on the applications priorities and frame rate requirements. As FG-SDS supports and uses the OpenGL ES 2.0 rendering API it is highly portable and flexible. We have implemented FG-SGS and evaluated its performance and effectiveness on an automotive embedded system. Our evaluations indicate that FG-SGS is able to ensure that required frame rates and deadlines of the high priority application are met, if the schedule is feasible. The overhead introduced by GPU scheduling is non-negligible but considered to be reasonable with respect to the GPU resource prioritization that we are able to achieve

    Mandelbrot and Julia Sets via Jungck-CR Iteration with s-convexity

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    In today’s world, fractals play an important role in many fields, e.g., image compression or encryption, biology, physics, and so on. One of the earliest studied fractal types was the Mandelbrot and Julia sets. These fractals have been generalized in many different ways. One of such generalizations is the use of various iteration processes from the fixed point theory. In this paper, we study the use of Jungck-CR iteration process, extended further by the use of s-convex combination. The Jungck-CR iteration process with s-convexity is an implicit three-step feedback iteration process. We prove new escape criteria for the generation of Mandelbrot and Julia sets through the proposed iteration process. Moreover, we present some graphical examples obtained by the use of escape time algorithm and the derived criteria

    Controlled Morphology and Its Effects on the Thermoelectric Properties of SnSe2 Thin Films

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    In the last few years, the thermoelectric properties of tin selenide (SnSe) have been explored in much detail due to its high efficiency and green nature, being free of Te and Pb. In the same chalcogenide family, SnSe2 is also a layered structured material, but its thermoelectric potential has not been widely explored experimentally. Since SnSe2 has the layered structure, its electrical transport properties may strongly be affected by its microstructure and morphology. Here, we report the effect of reaction time on the structure, phase, and morphology of the SnSe2 during solvothermal synthesis process. We have studied four SnSe2 samples with different reaction times. The sample obtained after 16 h of reaction time was named as M1, for 20 h M2, similarly for 24 h was M3 and for 48 hours’ time, the sample was named as M4. We investigated its thermoelectric properties and found that phase purity and morphology can affect the thermoelectric performance of the synthesized samples. The peak power factor (PF) value along the ab plane was (0.69 μWcm−1K−2) for the M4 sample at 575 K, which was the highest among all the measured samples. The comparatively larger PF value of sample M4 can be related to the increase in its electrical conductivity due to increase in phase purity and band gap reduction

    Computerized Tomographic Based Study of Thoracic Spine Morphology in Relevance to Pedicle Screw Fixation in Pakistani Population

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    Objective: To study the thoracic spine anatomy for accurate placement of pedicle screws using computerized tomography. Material and Methods: CT scans of 200 patients were included in our study. T1 to T12 vertebrae morphology was studied for each patient. Following measurements were taken, 1: Transverse pedicle width, 2 = Depth of anterior cortex along pedicle axis, 3 = Transverse pedicle angle, 4 = canal dimensions, 5 = vertebral body height anterior and posterior, 6 = mid vertebral body width. Results:  Transverse pedicle width decreased from T1 (4.06 ± 0.50 mm) to T4 (3.72 ± 0.17 mm) and then gradually increases to T12 (6.08 ± 0.60 mm). Depth of the anterior vertebral cortex remained constant from T1 to T4 and gradually increases up to T12. Transverse pedicle angle remained constant from T1 to T4 with a maximum at T4 (23.39 ± 3.15 mm) and then gradually decreased to T12 (3.99 ± 2.16 mm). Anteroposterior (AP) canal dimensions were minimum at T7 (17.03 ± 1.01 mm) and maximum at T2 (21.2 ± 1.07 mm). Interpedicular (IPD) canal dimensions were minimum at T6 (19.18 ± 1.6 mm) and maximum at T3 (23.18 ± 1.2 mm). Anterior vertebral body height was minimum at T1 (16.9 ± 1.34 mm) and maximum at T12 (27.14 ± 1.34mm). Posterior vertebral body height was minimum at T1 (18.8 ± 1.13 mm) and maximum at T12 (29.76 ± 1.43 mm). Conclusion:  A detailed anatomy of the thoracic spine is essential for surgical planning to decrease postoperative complications

    Efficacy of Balloon Kyphoplasty in Compression Fractures of the Thoracolumbar Spine

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    Objective:  To study the Efficacy of Balloon Kyphoplasty in compression fractures of the thoracolumbar spine. Material and Methods:  This study was conducted on 95 patients with thoracolumbar wedge fractures from 2017 to 2022. Complete neurological examination and CT and MRI scans of the spine of all patients were done. All patients have been treated with a balloon kyphoplasty procedure. Data was collected on VAS score, SF-36 score, kyphotic angle and percentage of vertebral body destruction both preoperatively and post-operatively. Statistical analysis was done by using paired sample t-test. Results:  The mean age was 57 years. Males were 58.9% and females 41.0%. Osteoporosis was the cause of fracture in 90.5% and trauma in 9.4% of patients. VAS improved from 7.42 ± 1.24 to post-procedure 3.24 ± 1.51, P < 0.0001. SF-36 improved from 35.31 ± 17.4 to post-procedure 49.23 ± 19.2, P < 0.0001. Kyphosis angle restoration from 18.42 ± 7.41 to post-procedure 10.61 ± 6.32, P value < 0.0001. Percentage loss of vertebral height from 32.91% to postoperatively 17.64% (SD-17.2 and P < 0.0001). 10.5% of patients developed cement leakage and there is no leakage in 89.4%. The adjacent level fracture occurred in 4 patients. Conclusion:  Balloon Kyphoplasty is an effective procedure for thoracolumbar wedge fractures. It improves pain, activities of daily living, kyphosis angle improvement, and restoration of vertebral height

    The impact of peripheral arterial disease on patients with mechanical circulatory support.

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    Background: Left ventricular assist devices (LVAD) are indicated as bridging or destination therapy for patients with advanced (Stage D) heart failure and reduced ejection fraction (HFrEF). Due to the clustering of the mutual risk factors, HFrEF patients have a high prevalence of peripheral arterial disease (PAD). This, along with the fact that continuous flow LVAD influence shear stress on the vasculature, can further deteriorate the PAD. Methods: We queried the National Inpatient Sample (NIS) database (2002-2014) to identify the burden of pre-existing PAD cases, its association with LVAD, in-hospital mortality, and other complications of LVAD. The adjusted odds ratio (aOR) and 95% confidence interval (CI) were calculated using the Cochran-Mantel-Haenszel test. Results: A total of 20,817 LVAD patients, comprising of 1,625 (7.8%) PAD and 19,192 (91.2%) non-PAD patients were included in the study. The odds of in-hospital mortality in PAD patients were significantly higher compared to non-PAD group (OR 1.29, CI, 1.07-1.55, P = 0.007). The PAD group had significantly higher adjusted odds as compared to non-PAD group for acute myocardial infarction (aOR 1.29; 95% CI, 1.07-1.55, P = 0.007), major bleeding requiring transfusion (aOR, 1.286; 95% CI, 1.136-1.456, P \u3c 0.001), vascular complications (aOR, 2.360; 95% CI, 1.781-3.126, P \u3c 0.001), surgical wound infections (aOR, 1.50; 95% CI, 1.17-1.94, P = 0.002), thromboembolic complications (aOR, 1.69; 95% CI, 1.36-2.10, P \u3c 0.001), implant-related complications (aOR, 1.47; 95% CI, 1.19-1.80, P \u3c 0.001), and acute renal failure (aOR, 1.26; 95% CI, 1.12-1.43, P \u3c 0.001). Conclusion: PAD patients can have high LVAD associated mortality as compared to non-PAD

    Recent advancements in the breeding of sorghum crop: current status and future strategies for marker-assisted breeding

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    Sorghum is emerging as a model crop for functional genetics and genomics of tropical grasses with abundant uses, including food, feed, and fuel, among others. It is currently the fifth most significant primary cereal crop. Crops are subjected to various biotic and abiotic stresses, which negatively impact on agricultural production. Developing high-yielding, disease-resistant, and climate-resilient cultivars can be achieved through marker-assisted breeding. Such selection has considerably reduced the time to market new crop varieties adapted to challenging conditions. In the recent years, extensive knowledge was gained about genetic markers. We are providing an overview of current advances in sorghum breeding initiatives, with a special focus on early breeders who may not be familiar with DNA markers. Advancements in molecular plant breeding, genetics, genomics selection, and genome editing have contributed to a thorough understanding of DNA markers, provided various proofs of the genetic variety accessible in crop plants, and have substantially enhanced plant breeding technologies. Marker-assisted selection has accelerated and precised the plant breeding process, empowering plant breeders all around the world. Copyright © 2023 Baloch, Altaf, Liaqat, Bedir, Nadeem, Cömertpay, Çoban, Habyarimana, Barutçular, Cerit, Ludidi, Karaköy, Aasim, Chung, Nawaz, Hatipoğlu, Kökten and Sun

    Morphological and molecular characterization of Oyster mushroom (Pleurotus spp.)

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    Mushrooms have medicinal as well as nutritive value and extensively used as human food from the time immortal. In order to determine the genetic diversity among Pleurotus species of mushroom using morphological and random amplified polymorphic DNA (RAPD) markers, about seven different species were collected. Five species, naming Pleurotus platypus (P-6), Pleurotus flabelatus (P-7), Pleurotus florida (P-17), Pleurotus ostreatus (P-19) and Pleurotus sajor-caju (P-56) were from Canada and two Pleurotus warm-stram (P-9) and Pleurotus eryngii (P-16) from Philpines. Seven different morphological traits that is, mycelial growth (mm), cap diameter (cm), total yield (kg), moisture contents (%), ash contents (%), nitrogen contents (%) and protein content (%) were recorded. The dendrogram based on morphological data divided seven species in cluster ‘A’ and ‘B’ having four and three species, respectively. The dendrogram based on RAPD analysis generated 3 clusters ‘A’, ‘B’ and ‘C’. Out of 14 random primers, the maximum polymorphism was observed by primers OPL3 (72.70 %) and OPL11 (70%). The two species P-56 and P-17 were observed to be most similar having value 86% and constituting a cluster ‘A’. The present work revealed that, morphological and RAPD markers showed different pattern of genetic diversity among different Pleurotus species.Keywords: Oyster mushrooms, genetic diversity, random amplified polymorphic DNA (RAPD) markers, dendrogra
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