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41.
This paper presents a unique technique to control a photovoltaic (PV)-powered piston-type water pump. the method uses a linear motor mounted directly onto the piston rod of the pump. This linear motor method replaces the traditional piston-type water pump, which employs a DC motor with a bulky gear mechanism to convert the rotational motion of the motor to linear motion for the piston. The electric circuit used to control the linear motor employs a four-quadrant chopper, which uses four fast MOSFETs and a simple logic circuit for the switching. The experimental results show that the PV-powered linear motor system can be used as an alternative to the PV-powered DC motor gear system. 相似文献
42.
Fred J. Eller Robert J. Bartelt Baruch S. Shasha David J. Schuster David G. Riley Philip A. Stansly Thomas F. Mueller Kenneth D. Shuler Bruce Johnson James H. Davis Carol A. Sutherland 《Journal of chemical ecology》1994,20(7):1537-1555
This study describes the identification of an aggregation pheromone for the pepper weevil,Anthonomus eugenii and field trials of a synthetic pheromone blend. Volatile collections and gas chromatography revealed the presence of six male-specific compounds. These compounds were identified using chromatographic and spectral techniques as: (Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (E)-2-(3,3-dimethylcyclohexylidene)ethanol, (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid), and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol). The emission rates of these compounds from feeding males were determined to be about: 7.2, 4.8, 0.45, 0.30, 2.0, and 0.30µg/male/day, respectively. Sticky traps baited with a synthetic blend of these compounds captured more pepper weevils (both sexes) than did unbaited control traps or pheromone-baited boll weevil traps. Commercial and laboratory formulations of the synthetic pheromone were both attractive. However, the commercial formulation did not release geranic acid properly, and geranic acid is necessary for full activity. The pheromones of the pepper weevil and the boll weevil are compared. Improvements for increasing trap efficiency and possible uses for the pepper weevil pheromone are discussed. A convenient method for purifying geranic acid is also described.The mention of firm names or trade products does not imply endorsement or recommendation by the U.S. Department of Agriculture over other firms or similar products not mentioned. All programs and services of the U.S. Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status or handicap. 相似文献
43.
Mohd Azrai Azman Carol K. H. Hon Martin Skitmore Boon Liat Lee Bo Xia 《Construction Management & Economics》2019,37(2):72-88
There is a need for a better approach to measure construction productivity rigorously, multilaterally, longitudinally and decomposed into its components. In response, this paper offers a robust approach to analysing construction productivity at the firm level that has been lacking in the industry to date, by measuring the Total Factor Productivity (TFP) of 37 public-listed Malaysian construction firms over 14 years (2003–2016), based on the Färe-Primont index. In comparing different groups of building, civil and specialist construction firms, this is the first application of a meta-frontier framework to capture the technological gaps involved. Based on the construction firms’ financial data, it is found that TFP improvement generally occurs due to Technical Efficiency (TE) and Scale-Mix Efficiency (SME) (largely scope economies), and significant technological gaps exist among different groups. Moreover, the industry suffered a decline in technologically related production environment over the period – prompting the conclusion that long-term policy engagement should focus on technological improvements. The paper provides a robust approach to analysing construction productivity at the firm level that also can be used for accessing productivity components and technological gaps in construction and other industries. 相似文献
44.
Shruti Deshmukh Stephen Burbine Erin Keaney Shib Shankar Banerjee Artee Panwar Christopher Peters Mary Herndon Derrick Rockosi Joey Mead Carol Barry 《Polymer Engineering and Science》2020,60(11):2782-2792
Highly-filled polymer systems include color masterbatches, feedstocks for powder injection molding, and rigid sheets with high levels of flame retardants, but they have not been explored for flexible sheet. This work investigated the (a) selecting a polymer matrix with enough melt strength and flexibility to form a stable sheet with high filler loading, (b) the maximum achievable filler loading for the sheet, and (c) optimizing the process of extruding a highly-filled flexible polymer system. Extrusion grade low-density polyethylene (LDPE) provided sufficient flexibility and permitted a maximum filler loading of 36 vol% (~78 wt%). Good dispersion of the nanoparticle filler, however, required two passes through multiple screw extruders and a small reduction in the viscosity of the LDPE. Sheet with thickness of 415 μm, surface roughness of <1 μm, and sufficient flexibility was extruded continuously at a rate of 10 m/min., but it required a more traditional coat hanger manifold to prevent filler hang up in the sheet die. The filler particles were distributed uniformly through the core and skin of the sheet, giving the sheet good mechanical properties. 相似文献
45.
46.
Aaron D. Krabill Hao Chen Dr. Sajjad Hussain Dr. Chao Feng Dr. Ammara Abdullah Prof. Chittaranjan Das Dr. Uma K. Aryal Prof. Carol Beth Post Prof. Michael K. Wendt Prof. Paul J. Galardy Prof. Daniel P. Flaherty 《Chembiochem : a European journal of chemical biology》2020,21(5):712-722
The deubiquitinase (DUB) ubiquitin C-terminal hydrolase L1 (UCHL1) is expressed primarily in the central nervous system under normal physiological conditions. However, UCHL1 is overexpressed in various aggressive forms of cancer with strong evidence supporting UCHL1 as an oncogene in lung, glioma, and blood cancers. In particular, the level of UCHL1 expression in these cancers correlates with increased invasiveness and metastatic behavior, as well as poor patient prognosis. Although UCHL1 is considered an oncogene with potential as a therapeutic target, there remains a significant lack of useful small-molecule probes to pharmacologically validate in vivo targeting of the enzyme. Herein, we describe the characterization of a new covalent cyanopyrrolidine-based UCHL1 inhibitory scaffold in biochemical and cellular studies to better understand the utility of this inhibitor in elucidating the role of UCHL1 in cancer biology. 相似文献
47.
Hiwot Abebe Haileslassie Carol J. Henry Robert T. Tyler 《International Journal of Food Science & Technology》2019,54(8):2540-2552
Pulses are processed in diverse ways prior to consumption. Soaking and germination are among the most common traditional, household-level food processing strategies. This study was carried out to determine the effects of soaking, germination, cooking and their combinations on the contents of selected nutrients and anti-nutrients of red dry bean and chickpea. In addition, the effects of pre-treatment on cooking time and the acceptability of dishes prepared from red dry bean and chickpea were determined. The nutrient compositions (zinc, iron and calcium) of most soaked-cooked and germinated-cooked red dry bean and chickpea samples were not significantly different than those of respective controls. However, soaking and germination pre-treatments significantly lowered the phytate and tannin contents of the red dry bean and chickpea samples, with a few exceptions, and overall, polyphenol contents were lower after soaking-cooking than after germination-cooking. Most scores for sensory attributes of bean-based and chickpea-based dishes prepared from soaked or germinated samples were not significantly different than those of the controls. For most red dry bean and chickpea samples, longer germination times yielded superior results in terms of reductions in cooking time, tannin content, and phytate:zinc and phytate:iron molar ratio. 相似文献
48.
49.
Empathic accuracy in a clinically relevant setting. 总被引:1,自引:0,他引:1
Marangoni Carol; Garcia Stella; Ickes William; Teng Gary 《Canadian Metallurgical Quarterly》1995,68(5):854
This study addressed 3 questions regarding empathic accuracy in a clinically relevant setting. First, does the empathic accuracy of a perceiver improve with increased exposure to a target individual? Second, can empathic accuracy be enhanced by providing the perceiver with feedback about the target's actual thoughts and feelings? Third, are there stable individual differences in empathic accuracy that generalize across different targets? The results indicated that although absolute performance levels varied from 1 target to another, empathic accuracy generally improved with increased exposure to the target. In addition, feedback concerning the target's actual thoughts and feelings accelerated the rate at which the perceivers' empathic accuracy improved. Finally, cross-target consistency in responding (α?=?.86) revealed stable individual differences in the perceivers' empathic ability. Implications of these findings for clinical training and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
R Ramanathan RA Mancini CB Van Buiten SP Suman CM Beach 《Journal of food science》2012,77(8):C886-C892
Our overall objective was to better understand the effects of added pyruvate on enhanced beef color stability. The 2 possible mechanisms assessed were the role of pyruvate in lipid oxidation and direct interaction between pyruvate and beef myoglobin. Microsomes were incubated with pyruvate at pH 5.6, 25 °C, and lipid oxidation was measured hourly for 3 h. Bovine oxymyoglobin at pH 5.6 was incubated with pyruvate and used to quantify both redox stability (metmyoglobin formation) and pyruvate-myoglobin adduction using mass spectrometry analysis. Surface color and lipid oxidation were measured on ground beef patties stored for 6 d in polyvinyl chloride over-wrap (PVC) or high oxygen. Addition of pyruvate to microsomes decreased lipid oxidation compared with controls (P < 0.05). Conversely, no effect on myoglobin was observed (no changes in redox stability and no peaks corresponding to pyruvate were observed; P > 0.05). However, pyruvate increased color stability and decreased lipid oxidation of ground beef patties packaged in PVC and high oxygen. Pyruvate decreased nitric oxide metmyoglobin-reducing capacity and oxygen consumption of patties compared with controls (P < 0.05). This research suggests that pyruvate may improve beef color stability primarily through its antioxidant effect on lipids. Practical Application: Discoloration of meat often results in significant revenue loss. This study suggests that pyruvate can improve the color stability of patties packaged in high oxygen and PVC primarily through its antioxidant effect on lipids. 相似文献