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Technologic ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Setia Abikusna Abikusna

PT. XYZ menyediakan layanan perbaikan kategori general repair bagi pelanggannya. Pada layanan ini, terdapat kendala yaitu lead time proses servis berkala eksternal (SBE) tidak mencapai target, khususnya pada proses penggantian oli mesin Fortuner. Proses ini dirasa masih kurang efektif karena teknisi kerap harus membersihkan cross member dan lower cover, serta lantai stall karena ada tetesan oli ketika proses penggantian oli dilakukan, hal ini yang menyebabkan waktu servis menjadi lebih lama. Dalam mencari solusi atas permasalahan yang terjadi, penulis menggunakan tools fishbone diagram untuk membuat improvement mempercepat penggantian oli mesin Fortuner dengan membuat service special tools (SST) berupa penampang oli mesin sehingga memudahkan teknisi melakukan penggantian oli mesin. Hasil dari improvement tersebut mempercepat lead time proses SBE dari 1 jam 2 menit 59 detik menjadi 54 menit 39 detik.


2021 ◽  
pp. 1-25
Author(s):  
Amit Segev ◽  
Itay J. Reznik ◽  
Uri Schattner

Abstract The Yarmouk River gorge extends along the Israel–Jordan–Syria border junction. It marks the southern bound of the Irbid–Azraq rift and Harrat Ash Shaam volcanic field at their intersection with the younger Dead Sea Transform plate boundary. During the last ∼13 Ma, the gorge has repeatedly accumulated basaltic units, chronologically named the Lower, Cover, Yarmouk and Raqqad Basalt formations. We examined their origin and distribution through aerial photos, and geological and geophysical evidence. Our results define a southern Golan magmatic province, which includes exposed Miocene (∼13 Ma) basalts, gabbro–diabase intrusions below the gorge and the adjacent Dead Sea Transform valley, and numerous Pliocene–Pleistocene volcanic sources along the gorge. Cover Basalt (∼5.0–4.3 Ma) eruptions formed two adjacent 0–100 m thick plateaus on the transform shoulder before flowing downslope to fill the topographically lower Dead Sea Transform valley with ∼700 m thick basalts. Later incision of the Yarmouk River and displacement along its associated fault divided the plateaus and formed the gorge. The younger Yarmouk (0.8–0.6 Ma) and Raqqad (0.2–0.1 Ma) basalts erupted in the upper part of the gorge from volcanos reported here, and flowed downstream toward the Dead Sea Transform valley. Consequently, eruptions from six phreatic volcanic vents altered the Yarmouk River morphology from sinuous to meandering. Our results associate the ∼13 Ma long southern Golan volcanism with the proposed SW-trending extensional Yarmouk Fault, located east of the Dead Sea Transform. Hence, the Yarmouk volcanism is associated with the ongoing Harrat Ash Shaam activity, which is not directly linked to the displacement along the Dead Sea Transform.


Author(s):  
G.V. Kuznetsov ◽  
K.O. Ponomarev ◽  
D.V. Feoktistov ◽  
E.G. Orlova ◽  
H. Ouerdane ◽  
...  

Weed Science ◽  
2017 ◽  
Vol 65 (3) ◽  
pp. 426-439 ◽  
Author(s):  
Jeffrey A. Liebert ◽  
Antonio DiTommaso ◽  
Matthew R. Ryan

Maximizing cereal rye biomass has been recommended for weed suppression in cover crop–based organic no-till planted soybean; however, achieving high biomass can be challenging, and thick mulch can interfere with soybean seed placement. An experiment was conducted from 2012 to 2014 in New York to test whether mixing barley and cereal rye would (1) increase weed suppression via enhanced shading prior to termination and (2) provide acceptable weed suppression at lower cover crop biomass levels compared with cereal rye alone. This experiment was also designed to assess high-residue cultivation as a supplemental weed management tool. Barley and cereal rye were seeded in a replacement series, and a split-block design with four replications was used with management treatments as main plots and cover crop seeding ratio treatments (barley:cereal rye, 0:100, 50:50, and 100:0) as subplots. Management treatments included high-residue cultivation and standard no-till management without high-residue cultivation. Despite wider leaves in barley, mixing the species did not increase shading, and cereal rye dominated cover crop biomass in the 50:50 mixtures in 2013 and 2014, representing 82 and 93% of the biomass, respectively. Across all treatments, average weed biomass (primarily common ragweed, giant foxtail, and yellow foxtail) in late summer ranged from 0.5 to 1.1 Mg ha−1in 2013 and 0.6 to 1.3 Mg ha−1in 2014, and weed biomass tended to decrease as the proportion of cereal rye, and thus total cover crop biomass, increased. However, soybean population also decreased by 29,100 plants ha−1for every 1 Mg ha−1increase in cover crop biomass in 2013 (P=0.05). There was no relationship between cover crop biomass and soybean population in 2014 (P=0.35). Soybean yield under no-till management averaged 2.9 Mg ha−1in 2013 and 2.6 Mg ha−1in 2014 and was not affected by cover crop ratio or management treatment. Partial correlation analyses demonstrated that shading from cover crops prior to termination explained more variation in weed biomass than cover crop biomass. Our results indicate that cover crop management practices that enhance shading at slightly lower cover crop biomass levels might reduce the challenges associated with excessive biomass production without sacrificing weed suppression in organic no-till planted soybean.


Author(s):  
Ruber Rodríguez-Barreras ◽  
María E. Pérez ◽  
Alex E. Mercado-Molina ◽  
Stacey M. Williams ◽  
Alberto M. Sabat

The long-spined sea urchin Diadema antillarum has been the focus of multiple studies since the mass mortality event in the 1980s. The recovery of this key herbivore in the wider Caribbean is essential for the well-being of coral reefs. This study examined the population density and structure of D. antillarum at seven northern fringing reefs of Puerto Rico between 2011 and 2013. The total mean density of the sea urchins in northern Puerto Rico was 0.9 ±0.3 ind m−2. Densities of D. antillarum significantly differed among sites, but not temporally. Differences in mean sizes were significant among sites and seasons. Areas with higher densities of D. antillarum showed lower cover of non-calcareous algae. Wave exposure was correlated with the abundance of the sea urchin. This study indicates that the observed abundance of D. antillarum has not yet returned to pre-mortality levels. However, densities showed some degree of recovery when compared with previous studies, enabling at least some degree of control on fleshy macroalgae communities. No significant changes in density occurred between 2011 and 2013, and sites with higher densities were generally located in leeward areas. The low relative abundance of small size individuals points towards recruitment limitation as an explanation for the limited recovery of D. antillarum.


2014 ◽  
Vol 496-500 ◽  
pp. 1473-1476
Author(s):  
Qi Zhang ◽  
Ying Jun Li ◽  
Gui Cong Wang ◽  
Ru Jian Ma ◽  
Xiu Yun Zhao

A new type of upper and lower cover support structure piezoelectric sensor based on PVDF films is designed in terms of piezoelectric effect. Mechanics and mathematical models are established according to the structure of the sensor. The natural frequency of the sensor is derived finally. The natural frequency of the sensor is verified to meet the requirements of dynamic measurements by using theoretical calculations and simulations. The effectiveness of the calculating method is indicated.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Eric Pante ◽  
Phillip Dustan

Ecological monitoring programs depend on the robust estimation of descriptive parameters. Percent cover, gleaned from transects sampled with video imagery, is a popular benthic ecology descriptor often estimated using point counting, an image-based method for identifying substrate types beneath random points. We tested the hypothesis that the number of points needed to robustly estimate benthic cover in video imagery transects depends on cover itself, predicting that lower cover will require more points/frame to be accurately estimated. While this point may seem obvious to the statistically inclined, the justification of point density has been largely ignored in the literature. We examined the statistical behavior of point count estimates using computer-simulated 20 m-long transects patterned after data from a Bahamian reef. The minimum number of points necessary to insure accurate percent cover estimation, the Optimal Point Count (OPC), is a function of mean percent cover and spatial heterogeneity of the benthic community. More points are required to characterize reefs with lower cover and more homogeneously distributed coral colonies. These results show that careful consideration must be given to sampling design and data analysis prior to attempting to estimate benthic cover, especially in the context of long-term monitoring of degrading coral reef ecosystems.


Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 753-761 ◽  
Author(s):  
Amanda S. Collins ◽  
Carlene A. Chase ◽  
William M. Stall ◽  
Chad M. Hutchinson

Additive experiments were performed to determine optimum densities for nematode-suppressive cover crops to extend the benefit from the cover crops by also using them for weed suppression. In a preliminary experiment in 2002, a range of cover-crop densities was evaluated in mixtures with smooth pigweed at 5 plants m−2. Smooth pigweed biomass accumulation was suppressed by cowpea, sunn hemp, and velvetbean at the lowest cover-crop populations (38, 44, and 15 plants m−2, respectively). Based on these results, experiments were conducted in 2003 at two locations to examine the effects of lower cover-crop densities on a higher smooth pigweed population density of 15 plants m−2. Cowpea and velvetbean densities ranged from 10 to 50 plants m−2 and sunn hemp from 20 to 100 plants m−2. In 2003, cowpea density had no effect on smooth pigweed biomass. However, smooth pigweed biomass declined linearly by 51% as sunn hemp density increased to 100 plants m−2. Similarly, as velvetbean densities increased, smooth pigweed biomass decreased showing a linear response at one location and quadratic response at the second location. Maximum suppression of smooth pigweed biomass by velvetbean occurred at the highest cover-crop density (50 plants m−2). Excellent suppression of smooth pigweed at 5 plants m−2 or fewer will result in densities of 38, 44, and 15 plants m−2 of cowpea, sunn hemp, and velvetbean. However, with smooth pigweed at 15 plants m−2, optimum cover-crop densities were not obtained because no suppression was obtained with cowpea, and the lowest weed biomass with sunn hemp and velvetbean occurred with the highest densities used. Therefore, when high smooth pigweed densities are expected, sunn hemp and velvetbean should be used at densities greater than 100 and 50 plants m−2, respectively, and further study with higher densities will be needed to define optima.


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