Journal Articles on Category: General Works

Experiment were conducted to study the crop coefficient (Kc) and water use Efficiency (WUE) of soybean as affected by soil moisture stress and fertility levels at Malir Experimental Farm, Sindh Agriculture University. Tnadojam, Pakistan on silt loam soil. The results revealed that crop efficient (Kc) increased with an increase in the crop age. The Kc was higher proportionate to higher moisture availability. The peak Kc was at 105-125 days after sowing, corresponding with early stage to complete fill stage of soybean crop. Water use efficiency at 5 bar tensions signified the plants under stress and were more efficient in utilizing water for the production of grain. The higher fertility was exhibited through appropriate fertilizer levels which in-turn increased the water use efficiency and compensated water deficiency. Thus, it is recommended that crop coefficient and fertility levels should be identified for obtaining maximum water use efficiency and yield targets.

Issn:18125654

Keywords: soybean ; crop coefficient ; moisture stress ; fertility levels ; yield

Volume: 2

Pages: 1096-1098

Field experiments on soybean variety Hampton-266A were carried out for three years at Sindh Agriculture University, Tandojam on silt loam soil. Factorial experiments in Randomized Complete Block with four replications were carried out with three soil moisture stress levels (3, 5 and 8 bar tension) and two fertility levels (NPK 50-60-30 and 50-90-30 kg ha-1). The data demonstrated that seed yield was highly significantly affected by moisture stress and fertility levels. The seed yield reduced by 28 and 20% at 8 and 15 bars respectively as compared to 3 bar soil moisture stress. The seed yield was about 10% more in 90 kg P2O5 Per hectare as compared to 60 kg P2O5 per hectare. It is therefore suggested that soybean crop should be irrigated when soil moisture reaches at the level of 3 bar, where satisfactory yield could be obtained.

Issn:18125654

Keywords: Soybean yield ; water stress ; phosphorus

Volume: 2

Pages: 560-562

Experiments were conducted aft Latif Experimental Farm, Sindh Agriculture Univeresity, Tandojam, Pakistan, to study the effect of water stress (different irrigation frequencies) on growth, yield and oil content of sunflower variety Hysun-33. The experiment was laid out in randomized complete block design with five water stress treatments replicated four times having plot size of 15 square maters. The result revealed highly significant differences for all the growth, yield and oil content characters. Water stress treatments comparison describes that four regular irrigations with 10-days interval upto physiological maturity and first irrigation after 40-days of sowing produced significantly tall plants, thickened stems, early flowering and maturity, big sized heads bearing maximum seeds, higher seed index and yield and oil content, followed by three irrigations at the interval of 15 days and first irrigation after 45 days of sowing.

Issn:18125654

Keywords: Sunflower ; water stress ; yield ; oil content

Volume: 2

Pages: 550-552

The hot film and the hot fibre were the tools of the measurements of the velosity, turbulence, and shear stress occurred in the model of the dump used in the study. The previous one was used to measure the horizantal velosity, and the latter was the tool of the turbulance and shear stress measurements. The present study is focused much on the experimental procedure for measurement of different parameters at variaus sections of the hydraulic dump and different froude numbers. Besides that, the present prediction are compared with some previous investigations in this field. Furthermore, the auther concluded that the suitable and sophisticated equipments are necessary in order to get real, and fast results.

Issn:18125654

Keywords: Turbulence intensities ; shear stress ; turbulence

Volume: 2

Pages: 522-525

The results of fatty acids analysis suggested that greater unsaturation occurred with increasing germination time. High temperature had a marked effect on fatty acid composition and caused significant changes especially in neutral lipid and glycollpid fatty acids. Small changes were also observed in phophollpid fatty acids. A large increase in free fatty acid was also found, since free fatty acids are known to be damaging to cells.

Issn:18125654

Keywords: Temperature ; cotton seedlings ; fatty acids ; lipids

Volume: 2

Pages: 97-99

A pot trial was executed on certain faba bean varieties (Giza Blanka, Giza 461, 634, 674 and 717) were grown in sandy soil at the green house of National Research Centre, for investigating to what extent biofertilization with a soil yeast Rhodotorula glutinis may lower the deleterious effect of salinity stress. Increasing salinity level was accompanied by decreasing dry weight particularly with the high concentration (6000 ppm). Inoculation with Rhodotorula augmented plant dry weight in all tested varieties in comparison with the uninoculated ones with increasing percents ranged from 17.78 to 8.18 being the highest with variety Giza 461 and the lowest with Giza 717. Each of protein level, soluble carbohydrate, potassium content and catalase activity in plant leaves of various varieties greatly affected by increasing salinity level. Inclusion of Rhodotorula glutinis to salinity treatments mitigated their adverse effects. On the other hand, each of sodium, proline and hydrogen peroxide contents in plant leaves was increased with increasing salinity levels. Bio-treatment of Rhodotorula glutinis resulted in reducing values of the previous parameters for all tested faba bean varieties either the salt tolerant or the sensitive ones

Issn:18125654

Keywords: Faba bean varieties ; salinity ; yeast strain ; germination ; protien ; protien ; ions soluble carbohydrate ; proline hydrogen peroxide ; catalase activity

Volume: 4

Pages: 93-99

Introducing an implant into a femur might reduce the natural stress distribution of the femur. The reduction could cause its density and volume shrinkage. The implant starts to loose and causes patients hardly to move, thus needed a revision surgery. The phenomenon of reduction in load was identified as stress shielding. Topology optimization method was employed in the analysis of model of implant, cement and femur in 3-dimension by using ANSYS 7.1. The objective of the optimization was to minimize implant compliance subjected to percentage of reduction in its initial volume (Vo) ranges from 30% up to 70% Vo. Results showed that implant with 50 or 60% Vo would produce closed boundary and hence were acceptable in shape. Both implants were compared in stress distribution with conventional implant and intact femur (without implant). Load transfer has increased in femur with the optimized implants compared to before optimize in medial and lateral side. Hence, it showed that the new optimized implants were better than the conventional implant in order to reduce stress shielding problem.

Issn:18125654

Keywords: Stress shielding ; topology optimization method ; hip prosthesis ; finite element analysis

Volume: 6

Pages: 2768-2773

In recent years, ergonomic assessment of risk factors associated with musculoskeletal injuries has been widely performed in the workplace. Risk assessment methods can be categorized into two groups: Macro- and micro-ergonomic risk assessment. One of macro-ergonomic risk assessment methods is relative stress index which aim is identification and correction of jobs with high risk. In this technique multiple parameters such as frequency, duration, repetition, weight, force, travel distance and horizontal distance are taken into account in six categories. Then, by using tables, they are changed into codes and are put into identified formulas. The output is relative stress index for job, task or subtask. This technique has been performed in pharmaceutical industry. For performing this research, all jobs of production line of this industry have been observed and categorized into 11 job groups. Results show that 10 out of 11 jobs are in the green zone and one job is in the yellow zone. According to statistical tests, in two out of six categories of RSI, there is significant difference between averages of at least two jobs and there is no significant difference between other four categories of RSI. According to obtained results and work condition, following suggestions present: Performing micro-ergonomic risk assessment for categories of RSIs which are not in appropriate zone; decreasing of load weight and in result decreasing of used force by workers; elimination of performing jobs with high repetition by workers and trying to find a way for doing these works automatically.

Issn:18125654

Keywords: Relative stress index ; RSI ; macro-ergonomy ; risk assessment

Volume: 6

Pages: 2715-2723

To have better understanding of the interaction mechanism for rock deformation and methane gas flow, the testing research on the effect of the effective stress on coal specimen under the action of 3-dimensional compression have been specially designed for this study. The triaxial compression tests to coal specimen containing methane gas are carried out with various confining stress and pore pressures. The result of this test showed that the empirical equations for effective stress coefficient are a bilinear function of variable with overall stress and pore pressure. The empiric equations can depict the dynamic deformation behavior of gassy coal under the action of pore pressure.

Issn:18125654

Keywords: Triaxial compression ; methane gas seepage ; coal specimen ; coupled effect ; effective stress

Volume: 6

Pages: 2635-2640

This paper presents a hyperbolic mathematical model to predict the complete stress-straincurve of drained triaxial tests on uniform dense sand. The model was formed in one equation withmany parameters. The main parameters that are needed to run the model are the confining pressure,angle of friction and the relative density. The other parameters, initial and final slopes of the stressstrain curve, the reference stress and the curve-shape parameter are determined as functions of theconfining pressure, angle of friction and the relative density using best fitting curve technique from theexperimental tests results. Drained triaxial tests were run on clean white uniform sand to utilize andverify this model. These tests were carried out at four levels of confining pressure of 100, 200, 300 and400 kPa. This model was used to predict the stress-strain curves for drained triaxial tests on quartzsand at different relative density using the data of Kouner [1] . The model predictions were comparedwith the experimental results and showed good agreements of the predicted results with theexperimental results at all levels of applied confining pressures and relative densities.

Issn:15469239

Keywords: Modeling ; stress ; strain ; water ; sand ; triaxial

Volume: 3

Pages: 2108-2113