Prediction of repair and maintenance costs of two-wheel tractors in Iran

Predicting of repair and maintenance (R&M) costs of tractors in any mechanized farm is necessary for owners and managers to obtain information on overall maintenance costs in order to control production cost. In this context a study was conducted to predict accumulated R&M costs (Y) of two-wheel drive (2WD) tractors based on total usage hours (X) in Misagh-e- Sabz Agribusiness Company in Iran. Recorded data from the company was used to determine regression models for predicting total R&M costs (as percentage of initial purchase price) based on total usage hours. The statistical results of the study indicated that in order to predict total R&M costs of 2WD tractors with based on usage hours of 2260 h or less the power regression model Y = 0.013 (X/100)1.677 with R2 = 0.976, and to predict total R&M costs of 2WD tractors with based on usage hours of 2260 hours or more the polynomial regression model Y = 0.004 (X/100)2 – 0.181 (X/100) + 4.373 with R2 = 0.998 is strongly suggested. Results of the study also indicated that total R&M costs predicted in this study were lower than those predicted in the previous studies. Cumulative life of 12000 hours, for instance, indicated an total R&M costs equivalent to 40.3% of initial purchase price. The most likely reasons that explain these differences between the predicted results in this study and those predicted in the previous studies probably can be attributed to new tractor technology for production during the last two decades and lower labor wages in Iran

Prediction of soil available phosphorus based on soil organic carbon

There are many cases in which it is desirable to determine relationships among some soil physical and chemical properties. In soil studies, soil available phosphorous (AP) are often determined using laboratory tests, but it may be more suitable and economical to develop a pedotransfer function which uses some easily available soil properties. In this study, a pedotransfer function for predicting soil AP from soil organic carbon(OC) was suggested and soil AP was estimated as a function of soil OC. The soil AP predicted from the soil AP pedotransfer function was compared to the soil AP determined by laboratory test using the paired samples test and the Bland-Altman approach. The soil AP predicted by the soil AP pedotransfer function was not significantly different from the soil AP determined by laboratory test (P>0.05). The mean difference between the soil AP pedotransfer function and laboratory test was 1.57 ppm (95% confidence interval: -2.88 and 6.03 ppm; P = 0.453). The standard deviation of the soil AP differences was 7.01 ppm. The statistical results of the study indicated that the soil AP pedotransfer function provides an easy, economic and brief methodology to estimate soil AP and in order to predict soil AP based on soil OC the pedotransfer function AP = 0.7927 e 4.9922 OC with R2 = 0.92 can be recommended

Messy Miracles

Blessed is she who has believed that the Lord would fulfill his promises to her!” - Luke 1:45 Sometimes we need our plans to fail for God’s plans to succeed

Student Week of Prayer Edition

“Therefore, as God’s chosen people, holy and dearly loved, clothe yourselves with compassion, kindness, humility, gentleness and patience.” (Colossians 3:12, NIV

Keeping Your Focus

When you keep your focus, you will not miss God’s flame. So Moses thought, “I will go over and see this strange sight—why the bush does not burn up.” When the Lord saw that he had gone over to look, God called to him from within the bush, “Moses! Moses!” And Moses said, “Here I am.” Exodus 3:3–

Fall Week of Prayer Edition

You will show me the path of life; In Your presence is fullness of joy; At Your right hand are pleasures forevermore. - Psalm 16:11 Our happiness and our holiness are not two separate things; they\u27re the same thing

Alone With God

Then Jacob was left alone; and a Man wrestled with him until the breaking of day. (Genesis 32:24 NKJV) By coming face-to-face with God, Jacob also came face-to-face with himself

A Bird\u27s-Eye View

“Look at the birds of the air, for they neither sow nor reap nor gather into barns; yet your heavenly Father feeds them. Are you not of more value than they?” - Matthew 6:26 I wonder if a bird sings because it trusts in God