scholarly journals Design and Validation of an Adjustable Large-Scale Solar Simulator

2021 ◽  
Vol 11 (4) ◽  
pp. 1964
Author(s):  
Daniele Colarossi ◽  
Eleonora Tagliolini ◽  
Paolo Principi ◽  
Roberto Fioretti
Keyword(s):  
Large Scale ◽  
Design Procedure ◽  
Spatial Arrangement ◽  
Luminous Flux ◽  
International Electrotechnical Commission ◽  
Solar Simulator ◽  
Class A ◽  
Pv Panel ◽  
Temporal Instability ◽  
Class B

This work presents an adjustable large-scale solar simulator based on metal halide lamps. The design procedure is described with regards to the construction and spatial arrangement of the lamps and the designed optical system. Rotation and translation of the lamp array allow setting the direction and the intensity of the luminous flux on the horizontal plane. To validate the built model, irradiance nonuniformity and temporal instability tests were carried out assigning Class A, B, or C for each test, according to the International Electrotechnical Commission (IEC) standards requirements. The simulator meets the Class C standards on a 200 × 90 cm test plane, Class B on 170 × 80 cm, and Class A on 80 × 40 cm. The temporal instability returns Class A results for all the measured points. Lastly, a PV panel is characterized by tracing the I–V curve under simulated radiation, under outdoor natural sunlight, and with a numerical method. The results show a good approximation.

Automatic Identification Systems – the Effects of Class B on the Use of Class A Systems

2006 ◽  
Vol 59 (2) ◽  
pp. 335-347 ◽  
Author(s):  
Andy Norris
Keyword(s):  
Low Cost ◽  
International Maritime Organization ◽  
Automatic Identification ◽  
International Electrotechnical Commission ◽  
Market Place ◽  
Data Link ◽  
Class A ◽  
Class B ◽  
Update Rate ◽  
The Impact

The standards for CSTDMA Class B AIS will shortly be published by the International Electrotechnical Commission and equipment will become available during 2006. The perceived benefits that Class B brings to leisure craft users and its relatively low cost will make it attractive in the market place. A rapid take-up of Class B use can therefore be expected. This paper considers the impact that increased use of Class B will have on users of Class A AIS that are compulsorily fitted to larger vessels to meet the requirements of the International Maritime Organization Safety of Life at Sea convention. The CSTDMA Class B system has been designed to prevent overloading of the AIS VHF data link. This is briefly reviewed but there are a number of other aspects that need to be considered. These include: the increased garbling of Class B messages compared to those of Class A; the problems accruing from the low update rate of Class B information; the increase in display information that will need to be managed; and the possible increase in inappropriate manoeuvres of leisure craft caused by misplaced reliance on AIS. As a result of the investigation the paper highlights the fact that Class B users must not assume that their own presence, in the form of Class B transmissions, will be particularly visible on the bridge of many SOLAS vessels. This will continue to be the case for many years into the future, until such vessels are mandated to carry radar with AIS target overlay capability.

Large-scale mapping of the catenas vegetation in Subarctic tundra

1995 ◽  
pp. 3-21
Author(s):  
S. S. Kholod
Keyword(s):  
Spatial Distribution ◽  
Vegetation Cover ◽  
Large Scale ◽  
Block Diagram ◽  
Abiotic Factors ◽  
Ecological Factors ◽  
Spatial Arrangement ◽  
Geological Time ◽  
Ecological Barriers ◽  
Functional Zones

One of the most difficult tasks in large-scale vegetation mapping is the clarification of mechanisms of the internal integration of vegetation cover territorial units. Traditional way of searching such mechanisms is the study of ecological factors controlling the space heterogeneity of vegetation cover. In essence, this is autecological analysis of vegetation. We propose another way of searching the mechanisms of territorial integration of vegetation. It is connected with intracoenotic interrelation, in particular, with the changing role of edificator synusium in a community along the altitudinal gradient. This way of searching is illustrated in the model-plot in subarctic tundra of Central Chukotka. Our further suggestion concerns the way of depicting these mechanisms on large-scale vegetation map. As a model object we chose the catena, that is the landscape formation including all geomorphjc positions of a slope, joint by the process of moving the material down the slope. The process of peneplanation of a mountain system for a long geological time favours to the levelling the lower (accumulative) parts of slopes. The colonization of these parts of the slope by the vegetation variants, corresponding to the lowest part of catena is the result of peneplanation. Vegetation of this part of catena makes a certain biogeocoenotic work which is the levelling of the small infralandscape limits and of the boundaries in vegetation cover. This process we name as the continualization on catena. In this process the variants of vegetation in the lower part of catena are being broken into separate synusiums. This is the process of decumbation of layers described by V. B. Sochava. Up to the slope the edificator power of the shrub synusiums sharply decreases. Moss and herb synusium have "to seek" the habitats similar to those under the shrub canopy. The competition between the synusium arises resulting in arrangement of a certain spatial assemblage of vegetation cover elements. In such assemblage the position of each element is determined by both biotic (interrelation with other coenotic elements) and abiotic (presence of appropriate habitats) factors. Taking into account the biogeocoenotic character of the process of continualization on catena we name such spatial assemblage an exolutionary-biogeocoenotic series. The space within each evolutionary-biogeocoenotic series is divided by ecological barriers into some functional zones. In each of the such zones the struggle between synusiums has its individual expression and direction. In the start zone of catena (extensive pediment) the interrelations of synusiums and layers control the mutual spatial arrangement of these elements at the largest extent. Here, as a rule, there predominate edificator synusiums of low and dwarfshrubs. In the first order limit zone (the bend of pediment to the above part of the slope) one-species herb and moss synusiums, oftenly substituting each other in similar habitats, get prevalence. In the zone of active colonization of slope (denudation slope) the coenotic factor has the least role in the spatial distribution of the vegetation cover elements. In particular, phytocoenotic interactions take place only within separate microcoenoses of herbs, mosses and lichens. In the zone of the attenuation of continualization process (the upper most parts of slope, crests) phytocoenotic interactions are almost absent and the spatial distribution of vegetation cover elements depends exclusively on the abiotic factors. The principal scheme of the distribution of vegetation cover elements and the disposition of functional zones on catena are shown on block-diagram (fig. 1).

مهارة الكلام منظور من عملية التعلم والتعليم في جامعة باتوسنجكر الاسلامية الحكومية سومطرى الغربية

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Suharmon Suharmon
Keyword(s):  
Teaching Strategies ◽  
Language Education ◽  
Arabic Language ◽  
Descriptive Statistics ◽  
Quantitative Approach ◽  
Motivation To Learn ◽  
Education Department ◽  
Class A ◽  
Class B ◽  
Speaking Skill

This research aims to obtain infomation about Arabic learning especially speaking skill in Arabic Language Education Department at IAIN Batusangkar. The research uses a quantitative approach. The instruments to collect the data are test and questionnaire. The data were analyzed using descriptive statistics. The results of the research state that the students’ speaking ability at class “ A “ are 28% low, 36% moderate, and 36% high. While, at class “B”, students’ speaking abilities are 36.4% low, 40,9% moderate, and 22.7% high. The cause of students’ low ability is the unappropriateness of teachers’ strategy in teaching speaking. There are about 96% students at class “A” agreed and 86.4% students at class “B” had similar answer. Another cause is students’ low motivation in learning. Class “A” students agreed for about 76% of them and 77% of class “B” students answered the same. From the finding, it can be concluded that the inability of students to speak Arabic can be overcomed by improving teaching strategies and encouraging maximum motivation  to learn Arabic.

scholarly journals Some kinematics of halo coronal mass ejections

2020 ◽  
Vol 29 (1) ◽  
pp. 81-88
Author(s):  
Virendra Kumar Verma ◽  
Nishant Mittal ◽  
Ramesh Chandra
Keyword(s):  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Coronal Holes ◽  
Geomagnetic Disturbances ◽  
Class A ◽  
Heliospheric Physics ◽  
Class B ◽  
The Mean ◽  
Class C

AbstractWe present an investigation of halo coronal mass ejections (HCMEs) kinematics and other facts about the HCMEs. The study of HCMEs is very important because HCMEs are regarded as the main causes of heliospheric and geomagnetic disturbances. In this study, we have investigated 313 HCMEs observed during 1996-2012 by LASCO, coronal holes, and solar flares. We find that HCMEs are of two types: accelerated HCMEs and decelerated HCMEs. The mean space speed of HCMEs is 1283 km/s while the mean speed of decelerated HCMEs and accelerated HCMEs is 1349 km/s and 1174 km/s, respectively. The investigation shows that 1 (0.3%) HCME was associated with class A SXR, 14 (4.7%) HCMEs were associated with class B SXR-flares, 87 (29.4%) HCMEs were associated with class C SXR-flares, 125 (42.2%) HCMEs were associated with class M SXR-flares and 69 (23.3%) HCMEs were associated with class X SXR-flares. The speed of HCMEs increases with the importance of solar SXR-flares. The various results obtained in the present analysis are discussed in the light of the existing scenario of heliospheric physics.

scholarly journals Image data of crumb structure of bread from flour of czech spring wheat cultivars

2011 ◽  
Vol 22 (No. 4) ◽  
pp. 133-142 ◽  
Author(s):  
I. Švec ◽  
M. Hrušková
Keyword(s):  
Image Analysis ◽  
Image Data ◽  
Analysis Data ◽  
Wheat Cultivars ◽  
Rheological Measurements ◽  
Class A ◽  
Bread Volume ◽  
Class B ◽  
Crumb Structure

Abstract: Baking quality of flour from six wheat cultivars (harvest 2002 and 2003), belonging to the quality classes A and B, was evaluated using the fermented dough test. Analytical traits of kernel and flour showed differences between the classes which were confirmed by the baking test with the full-bread-formula according to Czech method. In addition to standard methods of the bread parameters description (specific bread volume and bread shape measurements) rheological measurements of penetrometer and image analysis were used in effort to differentiate wheat samples into the quality classes. The results of the baking test proved significant differences in specific bread volumes – the highest volume in class A was obtained with the cultivar Vinjet and in class B with SG-S1098 – approx. 410 and 420 ml/100 g. Although significant correlations among image analysis data and specific bread volume having been proved, any image analysis parameter did not distinguish the quality classes. Only the penetronetric measurements made with bread crumb were suitable for such purpose (r = 0.9083; for  = 0.01). Among image analysis data the total cell area of the crumb had the strongest correlation with specific bread volume (r = 0.7840; for α = 0.01).    

Decentralized H ∞ control for damping power system oscillations

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Guo-Jie Li ◽  
Tek Lie
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Digital Simulation ◽  
Design Procedure ◽  
Disturbance Attenuation ◽  
System Stability ◽  
Frequency Noise ◽  
Stability Robustness ◽  
Norm Bound

AbstractInter-area oscillations are serious problems to large-scale power systems. A decentralized H ∞ generator excitation controller of a power system is proposed to damp the inter-area oscillations and to enhance power system stability. The design procedure for a linear composite system is presented in terms of positive semi-definite solutions to modified algebraic inequalities. The resulting controller guarantees closed-loop stability, robustness and an H ∞-norm bound on disturbance attenuation even under uncertainties such as high frequency noise. The control is decentralized in the sense that the control of each generator depends on local information only. The effectiveness of the H ∞ controller is demonstrated through digital simulation studies on a two-machine power system.

A 3-tier classification of cerebral arteriovenous malformations

2011 ◽  
Vol 114 (3) ◽  
pp. 842-849 ◽  
Author(s):  
Robert F. Spetzler ◽  
Francisco A. Ponce
Keyword(s):  
Surgical Outcomes ◽  
Arteriovenous Malformations ◽  
Neurological Deficits ◽  
Cerebral Arteriovenous Malformations ◽  
Pooled Data ◽  
Class A ◽  
Tier System ◽  
Class B ◽  
Class C

Object The authors propose a 3-tier classification for cerebral arteriovenous malformations (AVMs). The classification is based on the original 5-tier Spetzler-Martin grading system, and reflects the treatment paradigm for these lesions. The implications of this modification in the literature are explored. Methods Class A combines Grades I and II AVMs, Class B are Grade III AVMs, and Class C combines Grades IV and V AVMs. Recommended management is surgery for Class A AVMs, multimodality treatment for Class B, and observation for Class C, with exceptions to the latter including recurrent hemorrhages and progressive neurological deficits. To evaluate whether combining grades is warranted from the perspective of surgical outcomes, the 3-tier system was applied to 1476 patients from 7 surgical series in which results were stratified according to Spetzler-Martin grades. Results Pairwise comparisons of individual Spetzler-Martin grades in the series analyzed showed the fewest significant differences (p < 0.05) in outcomes between Grades I and II AVMs and between Grades IV and V AVMs. In the pooled data analysis, significant differences in outcomes were found between all grades except IV and V (p = 0.38), and the lowest relative risks were found between Grades I and II (1.066) and between Grades IV and V (1.095). Using the pooled data, the predictive accuracies for surgical outcomes of the 5-tier and 3-tier systems were equivalent (receiver operating characteristic curve area 0.711 and 0.713, respectively). Conclusions Combining Grades I and II AVMs and combining Grades IV and V AVMs is justified in part because the differences in surgical results between these respective pairs are small. The proposed 3-tier classification of AVMs offers simplification of the Spetzler-Martin system, provides a guide to treatment, and is predictive of outcome. The revised classification not only simplifies treatment recommendations; by placing patients into 3 as opposed to 5 groups, statistical power is markedly increased for series comparisons.

Performance Improvement Program for Kawasaki Gas Turbine

2017 ◽  
Author(s):  
Tomoki Taniguchi ◽  
Ryoji Tamai ◽  
Yoshihiko Muto ◽  
Satoshi Takami ◽  
Ryozo Tanaka ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Performance ◽  
Film Cooling ◽  
Gas Turbines ◽  
Large Scale ◽  
New Technologies ◽  
Design Procedure ◽  
Product Line ◽  
Combined Cycle ◽  
Improvement Program

Kawasaki Heavy Industries, Ltd (KHI) has started a comprehensive program to further improve performance and availability of existing Kawasaki gas turbines. In the program, one of the Kawasaki’s existing gas turbine was selected from the broad product line and various kinds of technology were investigated and adopted to further improve its thermal performance and availability. The new technologies involve novel film cooling of turbine nozzles, advanced and large-scale numerical simulations, new thermal barrier coating. The thermal performance target is combined cycle efficiency of 51.6% and the target ramp rate is 20% load per minute. The program started in 2015 and engine testing has just started. In this paper, details of the program are described, focusing on design procedure.

scholarly journals Neuropathologic Examination in Sudden Unexpected Deaths in Infancy and Childhood: Recommendations for Highest Diagnostic Yield and Cost-Effectiveness in Forensic Settings

2017 ◽  
Vol 7 (2) ◽  
pp. 182-199 ◽  
Author(s):  
Rebecca D. Folkerth ◽  
Jacqueline Nunez ◽  
Zhanna Georgievskaya ◽  
Declan McGuone
Keyword(s):  
Diagnostic Yield ◽  
Sinus Thrombosis ◽  
Age Determination ◽  
Febrile Seizures ◽  
Manner Of Death ◽  
Final Cause ◽  
Class A ◽  
Class B ◽  
Class C ◽  
Walker Malformation

In infants and toddlers (less than four years of age), determination of cause and manner of death often requires a complete autopsy. Few evidence-based guidelines exist regarding optimum nervous system sectioning in this population. Over a six-month interval and using a comprehensive section protocol, we categorized cases having neuropathological findings that were critical (Class A), contributory (Class B), or noncontributory (Class C) to the final cause and manner of death. We further evaluated which sections helped make this determination. Among 53 cases (44 infants, 9 toddlers; 26 girls, 27 boys), Class A neuropathology was noted in nine (16.9%). Seven infants had meningoencephalitis (2/7, 28.6%), craniospinal trauma (3/7, 42.8%), brainstem necrosis suggesting Leigh Disease (1/7, 14.3%), and hydrocephalus in Dandy-Walker malformation (1/7, 14.3%); two toddlers had inflicted craniospinal trauma (2/2, 100%). Class B factors were identified in 11/53 (20.8%), including recent hypoxic-ischemic lesions (2/11, 18.2%), meningitis or dural venous sinus thrombosis in systemic sepsis (2/11, 18.2%), multicystic encephalopathy following peripartum asphyxia (2/11, 18.2%), and microcephaly and delayed myelination (Cri-du-Chat Syndrome) (1/11, 9.09%). Class B also included three toddlers (3/11, 27.2%) with features of hippocampal dysgenesis, two in the setting of febrile seizures. Class C comprised normal brains (3/53, 5.7%), and those with findings of uncertain significance, such as white matter and brainstem gliosis (30/53, 56.6%). The sections most valuable for detection of relevant pathology, and thus recommended for routine sampling, were: 1) bilateral hippocampus; 2) cerebral cortex and leptomeninges; and 3) pons or medulla.

scholarly journals Exogenous Promoter Triggers APETALA3 Silencing through RNA-Directed DNA Methylation Pathway in Arabidopsis

2019 ◽  
Vol 20 (18) ◽  
pp. 4478 ◽  
Author(s):  
Benqi Wang ◽  
Jie Liu ◽  
Lei Chu ◽  
Xue Jing ◽  
Huadong Wang ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Molecular Mechanisms ◽  
Plant Reproduction ◽  
Vital Role ◽  
Abnormal Development ◽  
Class A ◽  
Methylation Pathway ◽  
Class B ◽  
Transgenic Lines ◽  
Morphological Defects

The development of floral organs plays a vital role in plant reproduction. In our research, the APETALA3 (AP3) promoter-transgenic lines showed abnormal developmental phenotypes in stamens and petals. The aim of this study is to understand the molecular mechanisms of the morphological defects in transgenic plants. By performing transgenic analysis, it was found that the AP3-promoted genes and the vector had no relation to the morphological defects. Then, we performed the expression analysis of the class A, B, and C genes. A dramatic reduction of transcript levels of class B genes (AP3 and PISTILLATA) was observed. Additionally, we also analyzed the methylation of the promoters of class B genes and found that the promoter of AP3 was hypermethylated. Furthermore, combining mutations in rdr2-2, drm1/2, and nrpd1b-11 with the AP3-silencing lines rescued the abnormal development of stamens and petals. The expression of AP3 was reactivated and the methylation level of AP3 promoter was also reduced in RdDM-defective AP3-silencing lines. Our results showed that the RdDM pathway contributed to the transcriptional silencing in the transgenic AP3-silencing lines. Moreover, the results revealed that fact that the exogenous fragment of a promoter could trigger the methylation of homologous endogenous sequences, which may be ubiquitous in transgenic plants.

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