length ratio
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Author(s):  
Paulo César de César ◽  
Augusto Campagna Torres ◽  
Carlos Henrique Pasqualotto Oliani ◽  
Marcelo Rodrigues de Abreu

Author(s):  
Jan Bezděk

The genus Liroetis Weise, 1889 is redefi ned. The following new synonymies are established: Liroetis Weise, 1889 = Siemssenius Weise, 1922, syn. nov. = Pseudoliroetis Laboissière, 1929, syn. nov. = Zangia Chen, 1976, syn. nov. Consequently, the following new combinations are proposed: Liroetis coeruleus (Jiang, 1990) comb. nov.; Liroetis latispinus (Chen, 1976) comb. nov.; Liroetis nigricollis (Jiang, 1990) comb. nov.; Liroetis pallidulus (Jiang, 1990) comb. nov. (all from Zangia); Liroetis nigropictus (Fairmaire, 1889) comb. nov. (from Leptarthra); Liroetis cheni (Lee, 2016) comb. nov.; Liroetis elongatus (Kimoto, 1977) comb. nov.; Liroetis jeanvoinei (Laboissière, 1929) comb. nov.; Liroetis jungchani (Lee, 2016) comb. nov.; Liroetis liui (Lee, 2016) comb. nov.; Liroetis metallipennis (Chûjô, 1962) comb. nov.; Liroetis modestus (Weise, 1922) comb. nov.; Liroetis nigriceps (Laboissière, 1929) comb. nov.; Liroetis rufi pennis (Chûjô, 1962) comb. nov.; Liroetis sulcipennis (Zhang & Yang, 2008) comb. nov.; Liroetis tsoui (Lee, 2016) comb. nov.; and Liroetis yuae (Lee, 2016) comb. nov. (all from Siemssenius). Two new species, Liroetis aurantiacus sp. nov., from continental South East Asia, and L. baolocanus sp. nov., from Vietnam, are described. A new substitute name, Liroetis medvedevi nom. nov., is proposed for L. nigricollis Medvedev, 2009 preoccupied by L. nigricollis (Jiang, 1990). The following new synonyms are established: Liroetis aeneipennis Weise, 1889 = L. tiemushannis Jiang, 1988, syn. nov.; Liroetis ephippiatus Laboissière, 1930 = Zangia signata Jiang, 1990, syn. nov. = L. postmaculatus Lopatin, 2004, syn. nov.; Liroetis leechi Jacoby, 1890 = L. verticalis Jiang, 1988, syn. nov.; Liroetis nigricollis (Jiang, 1990) = L. unicolor Zhang, Li & Yang, 2008, syn. nov.; Liroetis reitteri (Pic, 1934) = Pseudoliroetis trifasciata Jiang, 1992, syn. nov. The spelling of Liroetis tiemushannis Jiang, 1988 is fixed using the First Reviewer Principle. Species of Liroetis are divided into five species-groups based on the combination of the following characters: presence/absence of border on anterior pronotal margin, width/length ratio of pronotum, structure of aedeagus, presence/absence of metatibial spur. The established groups are: the aeneipennis group, the aurantiacus group, the flavipennis group, the fulvipennis group, and the grandis group. The gender of Liroetis is masculine.


Phytotaxa ◽  
2021 ◽  
Vol 528 (5) ◽  
pp. 269-278
Author(s):  
DESTARIO METUSALA ◽  
REZA SAPUTRA ◽  
TRIMANTO ◽  
NISYAWATI

Dendrobium dedeksantosoi, a new species of Dendrobium section Spatulata (Orchidaceae: Epidendroideae) from Maluku Islands, Indonesia, is described and illustrated. The flower of this new species is morphologically most similar to Dendrobium busuangense, but differs in having different shape and size of petals and lip as well as a different length ratio between column and column-foot.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brahim Benzougagh ◽  
Sarita Gajbhiye Meshram ◽  
Abdallah Dridri ◽  
Larbi Boudad ◽  
Brahim Baamar ◽  
...  

AbstractMorphometric analysis is a pertinent scientific approach in any hydrological analysis, and it is necessary in the progress and management of drainage basin. Identification of areas at risk of erosion, and the prioritization of 48 sub-watersheds of Inaouene basin, was done by using linear, relief and areal aspects of watershed. The research carried out the use of geographic information system spatial data. The linear aspects include stream number, stream sequence, stream length, and bifurcation ratio, mean length of stream order, stream length ratio, mean stream length ratio, and form factor. The areal aspect includes frequency of stream, drainage density, texture ratio, channel length constant, and overland flow maintenance length. Ultimately, the relief dimensions included relief proportion, relief and ruggedness number. The array of compound (Cp) values computed allow us to set the priority ranks and classify the sub-watershed into three priority ranks groups: low, moderate, and high priority. Such morphometric analyses can be used therefore as a watershed erosion status estimator to prioritize land and water conservation initiatives and natural resources management.


2021 ◽  
pp. 095605992110641
Author(s):  
Orsolya Gáspár

The tessellation of the first built geodesic dome structure (the first planetarium of Jena, designed by Walther Bauersfeld, built 1922–23) has been unknown until recently. While original documentation of the tessellation has been published, the concept behind it has not been uncovered. This article presents the evolution of the final tessellation based on Bauersfeld’s hand-written notes found in the Zeiss Archives in Jena. Bauersfeld contemplated various methods of subdivision and performed detailed calculations and optimality analysis on them—preceding the theoretical studies on the tessellation of geodesic domes by almost 30 years. His key findings, relevant and comparable with later studies are highlighted. The concept of the presumably final tessellation is revealed to be the equal-area triangulation of the sphere—which has to the author’s knowledge not been considered ever since for geodesic domes. The remarkably simple algorithm applied did not result in a theoretically exact solution (well known to Bauersfeld), but as shown in this article in engineering terms it got sufficiently close. Moreover, it is concluded that the resulting tessellation excels in terms of important parameters (e.g. edge length ratio, number of different edges) compared to existing practical and theoretical solutions.


Mathematics ◽  
2021 ◽  
Vol 9 (23) ◽  
pp. 3135
Author(s):  
Mehdi Dasineh ◽  
Amir Ghaderi ◽  
Mohammad Bagherzadeh ◽  
Mohammad Ahmadi ◽  
Alban Kuriqi

This study investigates the characteristics of free and submerged hydraulic jumps on the triangular bed roughness in various T/I ratios (i.e., height and distance of roughness) using CFD modeling techniques. The accuracy of numerical modeling outcomes was checked and compared using artificial intelligence methods, namely Support Vector Machines (SVM), Gene Expression Programming (GEP), and Random Forest (RF). The results of the FLOW-3D® model and experimental data showed that the overall mean value of relative error is 4.1%, which confirms the numerical model’s ability to predict the characteristics of the free and submerged jumps. The SVM model with a minimum of Root Mean Square Error (RMSE) and a maximum of correlation coefficient (R2), compared with GEP and RF models in the training and testing phases for predicting the sequent depth ratio (y2/y1), submerged depth ratio (y3/y1), tailwater depth ratio (y4/y1), length ratio of jumps (Lj/y2*) and energy dissipation (ΔE/E1), was recognized as the best model. Moreover, the best result for predicting the length ratio of free jumps (Ljf/y2*) in the optimal gamma is γ = 10 and the length ratio of submerged jumps (Ljs/y2*) is γ = 0.60. Based on sensitivity analysis, the Froude number has the greatest effect on predicting the (y3/y1) compared with submergence factors (SF) and T/I. By omitting this parameter, the prediction accuracy is significantly reduced. Finally, the relationships with good correlation coefficients for the mentioned parameters in free and submerged jumps were presented based on numerical results.


Author(s):  
Р. Али ◽  
Н.В. Тряскин

Суда в некоторых случаях эксплуатации могут двигаться в непосредственной близости друг от друга. Такой сценарий обычно связан с изменением полей давления и скорости вблизи корпуса судов, в результате чего возникают гидродинамические силы и моменты взаимодействия, которые сильно зависит от относительной длины. В этой статье была проведена серия систематических расчётов на двух корпусах KVLCC2, движущихся на большой глубине в безветренную погоду с одинаковой постоянной малой скоростью, не превышающей 4 уз., чтобы исследовать влияние отношения длин на силы и моменты гидродинамического взаимодействия. OpenFOAM, пакет CFD с открытым исходным кодом использовался для организации и проведения расчётов. Метод осреднения по Рейнольдсу уравнений Навье-Стокса (RANS) применялся для моделирования турбулентности. Хорошо известная модель турбулентности использовалась для замыкания уравнений Навье-Стокса. Числовые результаты, касающиеся поля скоростей и гидродинамического следа за судами, были обработаны, проанализированы, сопоставлены и показали хорошее согласование с экспериментальными результатами. Ships, during the lightering operations, are forced to sail in a close position to each other, such a scenario generally associates with a change in the pressure and velocity fields surrounding their hulls, as a result, interaction hydrodynamic forces and moments are generated which are strongly related to the relative length of the interacted ships. In this paper, a series of systematic computations were performed on two KVLCС2 hulls advancing in deep and calm water with the same constant low speed (full scale speed 4kt) in order to investigate the influence of the length ratio on the hydrodynamic interaction forces and moments during the lightering operation. OpenFOAM, an open-source CFD packet was used for carrying out the simulations, Reynolds Averaged Navier-Stokes (RANS) method was used for turbulence modeling and the well-known turbulent model k-ω SST was used to close RANS equations. Numerical results have been post-processed, analyzed, compared and found to be of a good agreement with the experimental results. The velocity fields and wake were presented and analyzed.


2021 ◽  
Vol 2120 (1) ◽  
pp. 012007
Author(s):  
K W Cheong ◽  
J H Lim

Abstract The thermoelectric performance of the segmented annular thermoelectric generators with the bismuth telluride and skutterudites has been investigated. The effect of the length ratio of the hot-segment leg to total length leg on the thermoelectric performance of the segmented annular thermoelectric generators is analysed and discussed and the optimization design of the annular thermoelectric generator with bismuth telluride and skutterudites as the materials with high thermoelectric performance is obtained. The result of the thermoelectric performance with the manipulated variable of the increase of length ratio, the output power, output voltage and efficiency of the segmented annular thermoelectric generators increase at the beginning then decrease afterwards. Additionally, to compare with the single bismuth telluride and skutterudites annular thermoelectric generators, the output voltage, output power and the conversion efficiency of the segmented annular thermoelectric generators can be improved twice. Lastly, the thermoelectric performance of the segmented annular thermoelectric generators operating in the changes of the temperature. The result has proved that as the temperature increase, the thermoelectric performance of the annular thermoelectric generator will also increase. Hence, the acquired results may be given some useful applications of the bismuth telluride and skutterudites on the segmented annular thermoelectric generators for waste heat recovery.


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