Formula Organik Cair untuk Menambah Masa Tanam Semanggi di Lahan Kering

Clover farmers in Semanggi Village, Community Unit 3 of Kendung Sememi, Surabaya, plant clover every year. Clover is a year-round plant. In the long dry season, it is very risky to die. With intensive watering treatment and organic fertilizer, it is expected to grow better and produce very high yields. A demonstration plot of clover land would provide innovation in optimal and eco-friendly clover cultivation. The method of activities in this training included lectures on understanding clover cultivation in dry land and how to provide the right fertilizer for clover. Preparation for Implementation, Preparation of Business Places, Demonstration of clover cultivation in dry land required a plot of land available with complete facilities. The tools needed were provided in the right amount so that the demonstration plot process was not complicated. The physical yield of clover, seen from the leaves, was quite satisfactory because the leaves were wide enough (quality) and would automatically increase the mass volume in terms of weight (quantity).

Influence of grain size on mechanisms of plastic deformation and yield stress

The influence of grain size on the physical yield strength of the polycrystal is considered by the method of cellular automata. The physical yield strength of the polycrystal in this model is defined as the stress at which, the plastic deformation covers the entire cross section of the sample from one edge to another. Three mechanisms of plastic deformation are considered. The first one is an initiation of plastic flow from grain to grain by dislocation pile-ups. The second one is plastic flow in different grains independently of each other under the action of external stress and the third one is intergranular slippage. Computer simulations have shown that at large grain sizes (d > 200 nm) deformation propagates from grain to grain by initiating dislocations pile-ups, since in this case pile-ups are quite powerful and have a large effect on neighboring grains. At average values of grain size (20 nm <d <200 nm) plastic deformation occurs in the grains independently of each other, and the external strain give a major influence on plastic deformation. With further reduction of the grain sizes (d <20 nm) the main mechanism of deformation is intergranular slippage. because in grains of this size are quite large image stresses that do not allow large dislocation clusters. In small grains the image forces are quite large to prevent large dislocation pile-ups formation, but the mass and volume of grain are quite small to turn or slip its under the action of external stresses. In accordance with these mechanisms, on the calculated dependence of the physical yield strength vs grain size, there are three areas with different angles of inclination in logarithmic coordinates. Keywords: yield point, grain size, Hall―Petch low.

Physical and Fuzzy Logic Modeling of a Flip-Chip Thermocompression Bonding Process

Flip-Chip connections using gold-to-gold, gold-to-aluminum, or gold-to-solder bondings or contacts enhanced by epoxy are low-cost alternatives to soldering. To assist their technology advancements, we have developed yield models for a representative assembly process with flip-chip, thermocompression bondings. Based on bonding mechanics, a physical yield model has been developed to characterize the process. Then, a fuzzy logic model has been established to improve the modeling’s accuracy by including experimental data. The physical yield model can predict the assembly yield as a function of forces and planarities of the end effector, bump height variations, bump geometries, mechanical properties corresponding to different materials and temperatures, and distribution patterns of bumps. Consistent with our experimental experience, the calculated force level for a high-yield process was around 3000 gmf for a 30-gold-bump chip with a bump diameter of 60 μm and a height of 50 μm. The fuzzy logic model can be trained and adjusted by the results of physical models and experiments. It correlates very well to the nonlinear relationships between the yield and the assembly parameters, and has a self-learning capability to update itself with new data. Such capabilities have been demonstrated by studying the bonding on a substrate with or without a compliant layer.