scholarly journals Spray Coverage and Biological Efficacy of Single, Twin Symmetrical, and Twin Asymmetrical Flat Fan Nozzles

2021 ◽  
Vol 24 (2) ◽  
pp. 92-96
Author(s):  
Akbar Aliverdi ◽  
Masoud Borghei

Abstract Proper selection of nozzle type and spray volume is essential to optimize herbicide dose, reducing its adverse environmental effects. It has not been sufficiently evaluated which nozzle type (twin symmetrical flat fan nozzle or the twin asymmetrical one) is more efficient and whether pinoxaden application is more efficient at a low or high spray volume. The spray coverage of a single, twin symmetrical, and twin asymmetrical flat fan nozzles, each in the sizes of 110015, 11002, 110025, 11003, 11004, and 11005 on the moisture-sensitive papers (MSPs) was investigated. The biological efficacy of treatments using pinoxaden against wild oat was investigated. Unlike other nozzle types, the single flat fan nozzle could not cover MSP placed vertically behind the nozzle trajectory. Except for the latter, each nozzle type could cover the MSPs more efficiently with increase in nozzle size. Generally, the nozzles’ performance was twin symmetrical > single = twin asymmetrical flat fan nozzles. A larger nozzle size improved the coverage of MSPs but increased the effective dose (ED50; dose that gives a 50% reduction in dry weight), indicating a decrease in the efficacy of pinoxaden. Among all treatments, the lowest ED50 value was obtained by the twin symmetrical flat fan nozzle 110015 (5.2 g a.i. ha−1). The smaller, more concentrated droplets are required to achieve optimal pinoxaden efficacy against wild oat, which can be provided by a twin symmetrical flat fan nozzle with a smaller size.

HortScience ◽  
2020 ◽  
Vol 55 (11) ◽  
pp. 1848-1852
Author(s):  
Larissa Larocca de Souza ◽  
Marcelo L. Moretti

Hazelnut (Corylus avellana L.) basal sprouts, or suckers, are removed to train trees as a single trunk, facilitating mechanization. Suckers are routinely controlled with herbicides, often by using nozzles that generate fine droplets and spray volumes as high as 934 L·ha−1, making spray drift a concern. Spray nozzle type and carrier volume can impact herbicide efficacy and drift. Field studies compared the efficacy of 2,4-D and glufosinate in controlling suckers when applied with a flat-fan nozzle, producing fine droplets, to a TeeJet air-induction nozzle, producing ultra-coarse droplets. These nozzles were evaluated at 187 and 374 L·ha−1. Nozzle and carrier volume did not affect the efficacy of 2,4-D based on control, sucker height, or dry weight. The efficacy of glufosinate was unaffected by nozzle type or spray volume in most evaluations. These results indicate that hazelnut suckers can be effectively controlled using drift-reduction nozzles with lower carrier volumes (187 L·ha−1). Drift-reduction nozzles, coupled with lower spray volume, can maintain herbicide efficacy, minimize drift risk, and reduce cost.


2017 ◽  
Vol 10 (1) ◽  
pp. 32-52
Author(s):  
Bonnie White

In 1917 the British government began making plans for post-war adjustments to the economy, which included the migration of surplus women to the dominions. The Society for the Overseas Settlement of British Women was established in 1920 to facilitate the migration of female workers to the dominions. Earlier studies have argued that overseas emigration efforts purposefully directed women into domestic service as surplus commodities, thus alleviating the female ‘surplus’ and easing economic hardships of the post-war period. This article argues that as Publicity Officer for the SOSBW, Meriel Talbot targeted women she believed would be ideal candidates for emigration, including former members of the Women's Land Army and affiliated groups. With the proper selection of female migrants, Talbot sought to expand work opportunities for women in the dominions beyond domestic service, while reducing the female surplus at home and servicing the connection between state and empire. Dominion authorities, whose demands for migrant labour vacillated between agricultural workers during the war years and domestic servants after 1920, disapproved of Talbot's efforts to migrate women for work in agriculture. Divergent policies led to the early failure of the SOSBW in 1923.


2020 ◽  
Vol 51 (2) ◽  
pp. 177-194
Author(s):  
Al-Ghamdi A.M. ◽  
El-Zohri M

We investigated the phytotoxicity of desert cotton (Aerva javanica) extracts on wild oat and wheat. Aqueous extracts from A. javanica roots, leaves and inflorescences collected from Jeddah and Al-Baha regions, Saudi Arabia were used. Generally, the allelopathic potential of water extracts of A. javanica collected from Jeddah were more in inhibitory to wild oat germination and seedlings growth than those from Al-Baha. In both regions, root extracts were inhibitory to wild oat followed by leaves and inflorescences extracts. All test aqueous extracts of both regions did not inhibit the wheat germination or seedlings growth.Whreas, the wild oat germination was reduced by root extracts 58.62 %, 28.62 % leaves extracts : 32.72 %, 17.72 % and inflorescences extract 28.11 %, 12.13 % by in plants samples collected from Jeddah and Al-Baha, respectively. Wild oat radical length was inhibited by root extracts 53.27 %, 32.84 % leaves 42.35 %, 9.63 % and inflorescences extracts 22.64 %, 16.75 % in case of Jeddah and Al-Baha plants, respectively. In pot culture experiment, all treatments markedly reduced the plant dry weight and soluble carbohydrates, proteins and free amino acids contents in wild oat. The differences in the allelopathic potentials of studied A. javanica extracts were related to the qualitative variations in their phytochemicals constituents. Our results showed that A. javanica extracts could be safely used to control wild oat growth in wheat fields after more detsaled research..


Author(s):  
D. Josephine Selvarani Ruth

AbstractNickel Titanium Naval Ordinance Laboratory (NiTiNOL) is widely called as a shape memory alloy (SMA), a class of nonlinear smart material inherited with the functionally programmed property of varying electrical resistance during the transformation enabling to be positioned as a sensing element. The major challenge to instrument the SMA wires is to suppress the wires’ nonlinearity by proper selection of two important factors. The first factor is influenced by the mechanical biasing element and the other is to identify the sensing current for the sensing device (SMA wires + biasing). This paper focuses on developing SMA wires for sensing in different orientation types and configurations by removing the non-linearity in the system’s output by introducing inverse hysteresis to the wires through the passive mechanical element.


1997 ◽  
Vol 119 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Kunsoo Huh ◽  
Jeffrey L. Stein

Because the behavior of the condition number can have highly steep and multi-modal structure, optimal control and monitoring problems based on the condition number cannot be easily solved. In this paper, a minimization problem is formulated for κ2(P), the condition number of an eigensystem (P) of a matrix in terms of the L2 norm. A new non-normality measure is shown to exist that guarantees small values for the condition number. In addition, this measure can be minimized by proper selection of controller and observer gains. Application to the design of well-conditioned controller and observer-based monitors is illustrated.


2016 ◽  
Vol 61 (1) ◽  
pp. 353-360 ◽  
Author(s):  
B. Dybowski ◽  
J. Szymszal ◽  
Ł. Poloczek ◽  
A. Kiełbus

Due to low density and good mechanical properties, aluminium alloys are widely applied in transportation industry. Moreover, they are characterized by the specific physical properties, such as high electrical conductivity. This led to application of the hypoeutectic Al-Si-Mg alloys in the power generation industry. Proper selection of the alloys chemical composition is an important stage in achievement of the demanded properties. The following paper presents results of the research on the influence of alloys chemical composition on their properties. It has been revealed that Si and Ti addition decreases electrical conductivity of the Al-Si-Mg alloys, while Na addition increases it. The mechanical properties of the investigated alloys are decreased by both silicon and iron presence. Sodium addition increases ductility of the Al-Si-Mg alloys.


2008 ◽  
Vol 600-603 ◽  
pp. 1199-1202 ◽  
Author(s):  
Philip G. Neudeck ◽  
David J. Spry ◽  
Andrew J. Trunek ◽  
Laura J. Evans ◽  
Liang Yu Chen ◽  
...  

This paper reports on initial results from the first device tested of a “second generation” Pt-SiC Schottky diode hydrogen gas sensor that: 1) resides on the top of atomically flat 4H-SiC webbed cantilevers, 2) has integrated heater resistor, and 3) is bonded and packaged. With proper selection of heater resistor and sensor diode biases, rapid detection of H2 down to concentrations of 20 ppm was achieved. A stable sensor current gain of 125 ± 11 standard deviation was demonstrated during 250 hours of cyclic test exposures to 0.5% H2 and N2/air.


1999 ◽  
Author(s):  
Richard A. Gaggioli ◽  
David H. Richardson ◽  
Anthony J. Bowman ◽  
David M. Paulus

Abstract The concept of available energy, as defined by Gibbs (1873b) is revisited. He gave representations of available energy for two circumstances. The first was the available energy of a “body,” for the case when a body, alone, is in a nonequilibrium condition and therefore has energy available. In turn, he presented the available energy of “the body and medium,” for the energy which is available because a body is not in equilibrium with some arbitrarily specified medium. Gibbs’ representations were graphical. Since Gibbs, representations with formulas have been developed and are common, for the “available energy of body and medium.” Gaggioli (1998a, b) has developed formulas which are more general, to represent “the available energy of the body (alone)” and to assign an exergy to subsystems of the body as a measure of each sub-system’s contribution to the available energy. In contrast to the available energy, exergy is an additive property, so that balance equations can be written. And the formulas are independent from any “medium,” which is important both theoretically and practically — because of its relevance to proper selection of “the dead state.” These issues are discussed and extended, after reviewing Gibbs development of available energy and additional concepts which he introduced, such as “available vacuum” and “capacity for entropy.” It is argued that these “availabililty” and “capacity” concepts are all equivalent to one another. In turn, because of interconvertability, it is seen that available energy is something more fundamental than “maximum useful work.” Furthermore, it is illustrated that available energy, equilibrium and stability, and thermostatic property relations are relative, to “constraints.”


2012 ◽  
Vol 1 (1) ◽  
pp. 36-40
Author(s):  
Ghulam Mostafa Khan

Proper selection of donor’s blood group is essential to prevent transfusion hazards. It is known that ABO antigen is fully developed at birth but the newborn baby does not produce ABO antibodies until 3 to 6 months of age. The ABO antibodies present in the serum of newborn babies are derived from mother’s blood due to placental transfer. So the blood group of the newborn baby is done by ABO antigen grouping (forward grouping) only, antibody grouping (reverse grouping) is not required. In case of transfusion of blood in newborn under 4 months of age, cross-matching of donor’s blood is done with the mother’s blood if it is available. We know, recipient’s same group of blood is always preferable in case of transfusion in adults or older children. But selection of blood for transfusion in the infants under 4 months of age depends on the mother’s blood group as well. If the mother’s blood group differs from the infant’s blood group, the infant’s same group of blood may not be selected for transfusion. For example, if the mother’s blood group is “O” and the newborn blood group is “A” or “B”, infant’s same group “A” or “B” group blood could not be transfused, because the anti-A & anti-B antibodies can be derived in the infant’s serum from mother’s blood which may react with the “A” or “B” antigen of the donor’s blood. In this case “O” group packed RBCs should be selected for transfusion. “O” group whole blood may contain IgG anti-A and anti-B antibodies in the plasma which can react with the “A” or “B” antigen of the infant’s blood. So to avoid anti-A & anti-B antibodies in “O” group, plasma should be discarded and the packed RBCs should be transfused. In case of Rh-negative mother with Rh positive baby, Rh antibody may develop in mother’s blood and Rh antibody may enter into baby’s circulation, in this case the infant should be transfused with Rh-negative blood to avoid Rh antigen & antibody reaction. So for the selection of blood for transfusion in newborn baby up to the age of 4 months mother’s blood group is important to select the appropriate blood. DOI: http://dx.doi.org/10.3329/jemc.v1i1.11138J Enam Med Col 2011; 1(1): 36-40


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