SISTEM DINAMIS KETERSEDIAAN DAGING SAPI DI PROVINSI BALI

The demand for beef in Bali Province is very high and dominated with hotels, restaurants, and cafes. The purpose of this research is to know the factors that influence the availability of beef, analyze the availability of beef, and make alternative policy recommendation that can be done in order to meet the demand of beef. This research was conducted in Bali Province using system dynamic approach. Simulation are conducted over a period of 10 year, starting from 2012 until 2021. Factors affecting beef availability is beef production and beef demand. Simulation results show that beef production in Bali Province has not been able to meet the demand of beef. The availability of beef in Bali Province tended to decline from the beginning of the simulation year to the end of the simulation year. Based on the simulation results of several scenarios, the most effective and possibly developed policy to meet the needs of beef is through the efforts of fattening cattle. Key words: dynamic system, availability, beef, simulations

Dinamika Kepemilikan Perkebunan Kelapa Sawit Di Provinsi Riau Sumatra Indonesia

Smallholder’s plantations represent 44% of oil palm in Indonesia, and they were known to have agronomic performance much lower than Estate ones. So there is large room for increasing the yield with sustainable cropping system. To better understand the heterogeneity of smallholder’s plantations, an agricultural diagnosis has been implemented in a specific place, Riau Province of Sumatra. This study led to well characterize the dynamics of plantation in the region and the diversity of rationalities. Among eight existing types of smallholding plots, there were only three types with yield hardly lower than those of the estate plantations. This reinforced the interest to implement diagnosis through the nutritional status of palms using data from foliar diagnosis and soil analysis. Key words : dynamic of plantation, palm oil, smallholders, Sumatra

Densification of domestic waste fills by dynamic compaction

Dynamic compaction of solid waste is important in landfill operations because increasing the density of the material increases the storage capacity of the landfill. Differential settlements are also reduced, which is important for the integrity of the cover system. In this paper, a case study concerning a waste disposal site situated at Maldegem, Belgium, is presented. It is shown that young landfills behave differently from old landfills. This phenomenon results from the biodegradation of the wastes. Moreover, it is shown that the depth of influence, the crater depth, the enforced settlement, and the peak particle velocity are affected by this ageing process. Key words: dynamic compaction, landfills, SASW method, waste.

Dynamic instability of seasonally thawing silty soils

The peculiarities of the dynamic behaviour of silty soils in laboratory experiments that simulate their interaction with gas mining equipment are analyzed. These seasonally thawing soils appear to be very sensitive to dynamic loading and sometimes even liquefaction. Several peculiarities of their dynamic behaviour include: (i) their special sensitivity to very definite and narrow vibration frequency ranges, which vary with grain size and moisture content, and result from the resonant effects in the soil; (ii) the redistribution of pore water during the vibration and subsequent regain; (iii) the thixotropic recovery of the soil after vibration, resulting in the regain of its strength over initial levels, water content and density being constant. Both dilatant and thixotropic effects take place in such soils during dynamic loading, distinguishing them from both clean sands and clayey soils. On the basis of the peculiarities of dynamic behaviour discussed, the authors consider such soils as dilatantly thixotropic dispersed systems. Key words : dynamic properties, soils, thixotropy, liquefaction, resonance, silts.

Design of dynamic compaction

In recent years dynamic compaction (DC) has become a popular method for deep improvement of loose cohesionless soils and man-made fills of disposed waste and rubble. One of the main problems facing design engineers and contractors is the assessment of the number of tamper drops, grid spacing, and layout of passes required to attain satisfactory improvement depth in the soil strata. Many DC sites have irregular subsurface conditions where it is difficult to interpret results from site exploration and verification tests. The industry has long been using a simple relationship to estimate the depth of improvement (influence depth). The estimates obtained from that empirical method may vary considerably and in many cases may be rendered useless for DC design. The paper describes a new, rational, and more comprehensive DC design method based on results from an extensive experimental model study of impact response in dry sand. Analysis of normalized impact energy and the resulting densification in the sand in terms of normalized dimensions of volumetric strain contours shows unique correlations that are used for the proposed design method for dynamic compaction in unsaturated sandy soils. Data from several DC sites fit well with the new method. With future studies of field results the proposed approach could eventually be calibrated and used for other types of soil conditions. Key words : dynamic compaction, design, impact, sandy soil, energy, plastic strains

Seismic response of tuned systems

A study is made of the seismic behaviour of tuned equipment–structure systems where one or both of the system components experience inelastic deformation. The response is determined using coupled and decoupled models of the system. The effect of various parameters such as mass ratio and yield level on the system response is evaluated.It was found that the mass ratio and yield level of the tuned inelastic system are the key parameters affecting the response of the coupled system. The response of the primary system is found to be insensitive to the variation of the yield level of the secondary system. In addition, the response obtained using uncoupled analysis of the equipment and structure system is generally higher than the response obtained using coupled analysis and may result in grossly overdesigned systems. Key words: dynamic, seismic, response, tuned, coupled, equipment, structure, earthquake, inelastic.

Sensitivity analysis with dynamic programming

A way is presented for making a sensitivity analysis to find by how much the total cost increases as one moves away from the optimal solution obtained by dynamic programming. It is illustrated using a simple storm drain optimization problem. Key words: dynamic programming, sensitivity analysis, optimization.