dry transport
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2021 ◽  
Author(s):  
Zachary M Portman

The ability to transport pollen from flowers back to the nest represents a key innovation in the evolution of bees from predatory wasp ancestors. Currently, the origin and evolution of pollen transport remains unsettled. Older hypotheses proposed that crop transport was the original mode of pollen transport, but more recent molecular phylogenies have cast doubt on that view. Instead, more recent hypotheses contend that external transport of dry pollen is ancestral in bees. Here, I propose a new hypothesis to explain the origin and subsequent evolution of pollen transport in bees. I propose that pollen transport arose from adult pollen-feeding behavior and that internal transport of pollen is ancestral in bees. This then led to the evolution of external moist transport, which first required a transition step whereby pollen is temporarily accumulated on the venter on a patch of specialized hairs. Finally, external glazed and dry transport evolved from external moist pollen transport, and the evolution of dry transport led to changes in the location of scopae from the original location on the hind tibia and basitarsus. I illustrate many of these hypothetical evolutionary steps using modern-day bee behavior as an example, with a particular focus on the bee Perdita tortifoliae. Examination of the evolution of pollen transport of pollen wasps (subfamily Masarinae) reveals that they have undergone a parallel evolutionary change. Overall, I lay out a broad hypothetical framework to explain the origin and subsequent evolution of pollen transport in bees. This marks a return to the earlier hypothesis that crop transport is ancestral, and it also represents the first in-depth hypothesis to explain how external transport of moistened pollen could have evolved. The evolutionary history of bees has many implications for the biology of bees in the present day, and I lay out a number of predictions that could help confirm or refute my hypotheses.


2019 ◽  
Vol 7 (2) ◽  
pp. 927
Author(s):  
Mas Bayu Syamsunarno ◽  
Abdul Syukur ◽  
Aris Munandar

Immotilization of live red swamp crayfish (Procambarus clarkii) in this research a used Nephelium lappaceum leaf extract as a natural anesthetic. The aims of this research were to determine the best concentration of the Nephelium lappaceum leaf extract as red swamp crayfish anesthesia and the optimum time of dry transportation system. This research method was an experimental laboratory with two replication with each concentration 0 ppm, 171 ppm, 294 ppm, 503 ppm, 863 ppm, 1479 ppm, 2535 ppm, 4345 ppm, and 7447 ppm. The study showed that the content of secondary metabolites from extracts of Nephelium lappaceum leaf were alkaloids, saponins, phenols hydroquinones, tannins, and flavonoids. The optimum concentration for anesthesia red swamp crayfish is 7447 ppm with passed out on 112 minutes and time conscious at 3 minutes. Dry transport time that produces the best survival rate was approximately 8 hours with the survival rate of 100%. The results of the measurement of the quality of the water before it extracts included, among others, the temperature of 29.2ºC, pH 5.9, DO 7.1 mg/L and TAN 0 mg/L. While the results of measurements of water quality after extracts included, among others, the temperature was 29ºC, pH 6.5, DO 6.8 mg/L, and TAN 0.026 mg/L.


2019 ◽  
Vol 6 (1) ◽  
pp. 93
Author(s):  
Muhammad Sholihul Abid, Endang Dewi Masithah, Prayogo

Abstract Nila (Oreochromis niloticus) is one of the leading commodity and each year will always be increased in both local and export markets. It’s in line and will continue to grow due to the tendency of shifting market demand for commodities is of the dead form of fish (frozen) or other processed into a form of life, especially for the needs of breeders on commodity stocks. One of the latest post-harvest technologies that can be applied in the handling of live fish is a fish transport system in the dry media without use of water as a medium of transport with the use of anesthesia using plants that naturally contain active compounds that have the potential as a anesthesia drugs. This study aimed to determine the length of time different fish living on the transportation system with particular concentration infusum dried leaves of durian (Durio zibethinus) effect on the survival rate of nila (O. niloticus). Methods of this study is an experiment with three replications with different concentration intervals. It consisted of a preliminary study to determine the potential infusum durian leaves as anesthesia and primary research material as a form of media applications on the system dry. This study was conducted at the Laboratory of the Faculty of Fisheries and Marine Airlangga University. The results showed that the effective concentration of durian leaves infusum used to transport test was 4100 ppm with an average induction time is 40 minutes and recovery time is 48 minutes. Durian leaves infusum use in nila with 4100 ppm concentration able to achieve the level of survival and long transportation times in a row 100%, 0 h, 88.89%; 2 h, 22.22%; 4 h, 0%; 6 h, and 0%, 8 h on media packaging live fish without water.


2019 ◽  
Author(s):  
Niels Vernes ◽  
Stephan Donia ◽  
Anthony van Ginkel ◽  
Jan de Jonge ◽  
Henning Selstad ◽  
...  
Keyword(s):  

Author(s):  
Onno A. J. Peters ◽  
René H. M. Huijsmans

In Heavy Marine Transport it is common practice to dry-transport large and heavy floating offshore structures. In general, loading and discharge of these floating cargoes on- and from heavy transport vessels is done at sheltered locations like harbors where sea-state and swell conditions are insignificant. Often these locations are at large distance from operating fields of the offshore structures, which means that the structures need to be towed from- or to these fields. To save time and costs, it is beneficial to perform the loading and discharge operations in the field. This necessitates a reconsideration of the maximum allowable wave condition such as to perform the loading- and discharge operations within specified time frame whilst ensuring safety of crew, cargo and heavy transport vessel. Since precise positioning of the cargo on the HTV cribbing beams is of importance to support the cargo on its structural strong points, the allowed relative horizontal motion during loading or discharge operations is limited to a fraction of the width of these cribbing beams. When increasing the maximum allowable wave conditions, relative horizontal motions between heavy transport vessel and cargo easily exceed these limits if only the standard handling equipment is used. Also, the loads in the handling equipment may exceed safe limits. This paper presents two methods including complementary equipment to reduce- and limit the relative horizontal motions. The first method is based on increasing the stiffness of the connection between cargo and heavy transport vessel. This means that there is a transition from a soft (standard handling) system with a low natural frequency to a stiff (clamping) system with high natural frequency. During this transition the system natural frequency will coincide with the wave frequent excitation force. Resonant behavior during the transition is avoided as the complementary equipment also employs a damping force. The second method is based on a closed-loop controller applied to the desired relative horizontal position. The resulting desired load to control the relative horizontal motion is then allocated to several line tension actuators. Contradictory to well-known Dynamic Positioning systems which control low frequent motions, motion control during offshore loading and discharge is performed on wave frequent behavior. This implies that the line tension actuators also need to deliver loads within a wave frequent time-frame. In fact, the peak tension needs to be obtained within a quarter of a wave period. System design and simulation results are presented. Depending on the cargo type, different solutions and operational aspects are discussed. Simulations are done for a typical cargo where both methods to reduce the relative horizontal motions are utilized.


1993 ◽  
Vol 33 (5) ◽  
pp. 663 ◽  
Author(s):  
RB Jones ◽  
JK Truett ◽  
M Hill

Optimum postharvest and storage treatments were investigated for cut immature branches of Eucalyptus crenulata Blakely & Beuzev. and Eucalyptus gunnii J. D. Hook. The application of the germicide BCDMH at 10 mg/L of active chlorine, 100 �L Agral-600/L. or 0.25% sucrose to vase solutions significantly enhanced vase life in E. crenulata Longevity in E. gunnii was significantly extended by sucrose (0.25-2% w/v), but not by germicides or Agral. Sucrose pulses (1-10% for 24 11 at 20�C) or exogenous ethylene (50 �L/L for 24 h at 20�C) had no effect on the longevity of either species. Both species produced very low levels of ethylene immediately after harvest and after a 24-h simulation of dry transport at 20�C. Longevity was not significantly altered in either species by 35 days of dry storage at 1�C. or by 7 days of wet storage (branches held in distilled water + 50 mg DICAJL) at 1�C, but declined significantly in both species after 7 days of wet storage at 10�C.


1987 ◽  
Vol 109 (3) ◽  
pp. 575-582 ◽  
Author(s):  
P. W. Eckels ◽  
T. J. Rabas

The transverse velocity of the condensing phase during dehumidification is analogous to the transverse velocity at the wall when exercising boundary layer control by fluid extraction through a permeable wall. Wet and dry pressure drop and heat transfer rates are analyzed for correlation using boundary layer suction theory. Data are presented for flat-plate finned-tube heat exchangers during air heating and dehumidification operations and the data show a significant effect of transverse velocity correlated by the boundary layer suction formulation. The condensate film is considered isothermal in this analysis and the results indicate that an improved modeling of the condensate film is required. We find that the transverse velocity of the condensing phase has an important effect on transport phenomena during dehumidification and that the validity of the Chilton–Colburn heat and mass transfer analogy in describing dehumidification is supported by these results. It should be noted that the dry data form the beginning of a plate fin heat exchanger data base. The present data show the effect of tube diameter and, independently, fin density variation on the Colburn and friction factors with all other geometric parameters held invariant.


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