Weevil seed damage reduces germination and seedling growth of hybrid American chestnut

2012 ◽  
Vol 42 (6) ◽  
pp. 1107-1114 ◽  
Author(s):  
Harmony J. Dalgleish ◽  
John T. Shukle ◽  
Robert K. Swihart

Seed predation by weevils (Coleoptera: Curculionidae) has been implicated as a limiting factor in oak recruitment throughout eastern US forests. We examined the effects of weevil seed predation on American chestnut (Castanea dentata (Marsh.) Borkh.). Although an introduced pathogen eradicated sexually reproducing populations of American chestnut in the early 1900s, the recent development of a blight-resistant hybrid makes reintroduction feasible. We nondestructively assessed the amount of weevil damage to seeds using X-ray imagery and traditional float test methods in American and blight-resistant hybrid chestnut. We quantified the effects of weevil damage on seed germination and seedling growth. The float test method misidentified damage for up to 50% of seeds, whereas the X-ray method misidentified only 3% of the sample. Germination declined with damage: the smallest damage level reduced germination from 94% to 32%. No seeds with >50% damage germinated. Weevil damage reduced seedling growth by 50% compared with undamaged seeds. Seedling size increased with seed size, but seed size had no effect on germination. Our results highlight the importance of orchard and seed processing practices that prevent weevil damage to chestnut seeds. Because they drastically reduce germination rates and seedling growth, weevils have the potential to limit seed regeneration and dampen rates of spread in populations following reintroduction.

2010 ◽  
Vol 5 (2) ◽  
pp. 155892501000500 ◽  
Author(s):  
Paul D. Beuther ◽  
Michael W. Veith ◽  
Kenneth J. Zwick

The quality of a paper towel is often judged based on how quickly it can wipe up a spill. However, the test methods currently available cannot repeatably measure significant differences in absorbent rate between samples. Recent round-robin testing evaluations by TAPPI and CEN organizations have shown that past methods, such as ASTM D5802–95 and TAPPI T561-pm [1], are unreliable due to high variability. The reasons for the lack of repeatability are unclear. The relation between the wicking mechanism and the fundamental absorbent properties needs to be better understood. This paper uses x-ray imaging to show the overall flow characteristics of fluid absorption within a towel, and compares the results to model predictions to show which parameters are important to the process. From this understanding, a revised test method is proposed that provides adequate statistical discernment of absorbent rate properties of tissue on a simple lab-bench scale device.


1985 ◽  
Vol 29 ◽  
pp. 1-15
Author(s):  
Viktor M. Hauk

AbstractTo evaluate the state of macro- and micro-residual stresses in cold rolled materials of 0.2 to 3 mm thickness the following test methods were used: Measurements of lattice spacing in different directions (φ,Ѱ)with X-rays and neutron-rays on many diffraction peaks. The X-ray method was employed on the surface of the sheet and of the thinned piece after removing several layers from both sides. The neutron-ray method allows measurements in the interior of a specimen and the average of the strain distribution of the total cross section. The etching deflection method determines the macro-residual stresses. The calculation of the macro- anci micro-residual stresses using X-ray elastic constants (XEC) for polycrystalline material and the compliances of single crystals for groups of grains are described. Homogeneous and heterogeneous materials like steels, (α + β)-brass, nickel and copper with 3 % silver were investigated. The state of residual stresses on the surface and with the depth over the cross section was evaluated or is in the final process of investigation.


Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.


Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2315
Author(s):  
Christian Meltebrink ◽  
Tom Ströer ◽  
Benjamin Wegmann ◽  
Cornelia Weltzien ◽  
Arno Ruckelshausen

As an essential part for the development of autonomous agricultural robotics, the functional safety of autonomous agricultural machines is largely based on the functionality and robustness of non-contact sensor systems for human protection. This article presents a new step in the development of autonomous agricultural machine with a concept and the realization of a novel test method using a dynamic test stand on an agricultural farm in outdoor areas. With this test method, commercially available sensor systems are tested in a long-term test around the clock for 365 days a year and 24 h a day on a dynamic test stand in continuous outdoor use. A test over a longer period of time is needed to test as much as possible all occurring environmental conditions. This test is determined by the naturally occurring environmental conditions. This fact corresponds to the reality of unpredictable/determinable environmental conditions in the field and makes the test method and test stand so unique. The focus of the developed test methods is on creating own real environment detection areas (REDAs) for each sensor system, which can be used to compare and evaluate the autonomous human detection of the sensor systems for the functional safety of autonomous agricultural robots with a humanoid test target. Sensor manufacturers from industry and the automotive sector provide their sensor systems to have their sensors tested in cooperation with the TÜV.


2019 ◽  
Vol 55 (4) ◽  
pp. 308-321 ◽  
Author(s):  
S. P. Osipov ◽  
E. Yu. Usachev ◽  
S. V. Chakhlov ◽  
S. A. Shchetinkin ◽  
O. S. Osipov

2014 ◽  
Vol 687-691 ◽  
pp. 3110-3115
Author(s):  
Gu Li ◽  
Zi Ming Fu ◽  
Jie Feng Yan ◽  
Bing Wen Li ◽  
Zhi Rong Cen

This paper analyzes and studies the definition of the voltage transformer secondary load, examines the practical purposes of the measured values of the voltage transformer secondary load, and presents a variety of testing methods to analyze and compare the differences. This paper gives the test methods of the voltage transformer secondary load when the connection of the voltage transformer is the Y / Y in a three-phase three-wire power supply system, filling the blank of this type of test method in the industry. When other units within the industry carry out such work, the conclusions of this paper are available for reference, and the conclusions of this paper can be referred when drafting relevant regulations in the future.


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