Traditional tree management is laborious and costly, thus this work aimed to study the performance of two different types of frond cutting saws (reciprocating saw and vibrating saw) and examine the two saws on five date palm varieties. Four parameters were examined, including cutting time for a single frond, the power needed for cutting a single frond, frond cutting productivity expressed as tree/h, and vibration conveyed to the worker’s hand. A field experiment was designed according to the nested randomized complete block design, including five date palm varieties as the main plot and the type of saw as a sub-plot. Means were compared using the least significant differences (LSD 0.05). Results indicated that Bream variety required the least time for frond cutting. The reciprocating saw exhibited efficiency in saving the time required for frond cutting, while the vibrating saw took significantly longer time needed for cutting a single frond. The highest number of fronds cut in one hour was recorded in Bream variety, again significantly higher than the number of other studied varieties. Moreover, the reciprocating saw achieved significantly higher productivity than the vibrating one, indicating that the productivity of the reciprocating saw is almost three times more than the vibrating saw. Maximum productivity was recorded in Bream variety, while the least was recorded in Tebarzal using the vibrating saw. Moreover, results indicate that the variety and the type of saw have a vital role in productivity since as the thickness of a frond increases, the cutting takes more time and ultimately reduces the number of date palms to be pruned per hour. Results also exhibited that vibrating saw reduced the consumed energy during frond cutting. Additionally, results revealed that the minimum power consumed by a vibrating saw was in Bream variety, while Tebarzal consumed the upmost energy when a reciprocating saw was used. Maximum vibration on X-axis was reported in Bream variety when a vibrating saw was used. Additionally, the reciprocating saw exhibited the highest vibration compared with the vibrating saw. Moreover, the reciprocating saw caused the lowest vibration in Tebarzal variety. Results indicated that the vibration imposed by both saws reached the maximum value in Bream variety. The vibrating saw resulted in the higher vibration toward Z axis, while the Reciprocating saw resulted in higher vibration toward X axis, which was more than eight times that recorded by the vibrating saw. Results indicate that vibration toward the Y axis increased significantly in Bream variety compared with others. Again, as in the situation with X and Z axis, the reciprocating saw exhibited the highest vibration compared to that resulted from using a vibrating saw which was more than three times the vibration caused by the vibrating saw.
An acidic environment causes surface changes of resin composites. Filler particlesize and filler distribution also have a direct effect on these surface changes. This invitro study evaluated the influence of Pepsi Cola drink on the surface roughness ofComposan LCM and Composan Ceram over time. Sixteen disc shaped specimens(10mm diameter, 2mm thickness) of each resin composite were fabricated, therebyforming two groups (n= 8). Surface roughness (Ra) was analyzed after 24 hrs beforeexposure to beverage. The specimens were submitted to a five minutes immersion inPepsi Cola three times daily interrupted by immersion in deionized distilled water (37C˚). Surface roughness measurements were done at 10, 30, and 60 days intervals. Datawere
... Show MorePurpose: studying and analyzing the nature of uncertainty as part of strategy formulation, through analyzing the uncertainty faced by managers in the modern business environment characterized by high complexity and dynamism, though developing of an idea about the uncertainty cases and how enable the mind to understand these cases.
Methodology: It was the use of inductive and analytical approach, in order to study the accumulation of knowledge towards development areas that could contribute to strengthening the strategy formulation.
Findings: Mentoring the future will not make the success for business organization but thought business organization ability to developing share mental
... Show MoreEducation specialists have differed about determining the best ways to detect the
talented. Since the appearance of the mental and psychological measurement movement, some
scholars adopted intelligence ratios as a criterion to identify the talented and others went to
rely on the degree of academic achievement. Each of these two methods has its own flaws and
mistakes and a large number of talented children were victims of these two methods.
Therefore the need to use other scales for the purpose of detection of talented children
appeared because they provide valuable information which may not be obtained easily
through objective tests and these scales are derived from consecutive studies of gifted andtalented children
A study of the singlet and triplet states of two electron systems in the first excited state was performed using a simple quantum mechanical model, which assigns the 1s,and 2s orbital with two different variational parameters. Our results agree with a high level calculation used by Snow and Bills.
The nuclear structure included the matter, proton and neutron densities of the ground state, the nuclear root-mean-square (rms) radii and elastic form factors of one neutron 23O and 24F halo nuclei have been studied by the two body model of within the harmonic oscillator (HO) and Woods-Saxon (WS) radial wave functions. The calculated results show that the two body model within the HO and WS radial wave functions succeed in reproducing neutron halo in these exotic nuclei. Moreover, the Glauber model at high energy has been used to calculated the rms radii and reaction cross section of these nuclei.
The problem of the research is focused on importance limited of Iraq industrial companies in application of scientific measurements of supply chains performance, The research sought to achieve a group of goals, the most important are , identifying the strengths and weaknesses in the reality of supply chain in General Company for Cotton Industries, The data and information required are gathered from the dependence company, records through the field observations and personal interviews, the research used some quantitative indicators to measure of supply chain performance, The research reached to many conclusions , the most outstanding among them is the existence of a strong inverse correlatio
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