Acceptance Analysis of PDAM Sleman’s Water Tariff Based on Revenue and Wilingness to Pay Projection

The Regional Water Company (PDAM) of Sleman provides clean water to the community and charges a tariff for each cubic meter of water sold to customers. Minister of Home Affairs Regulation No. 71 of 2016 states that PDAM tariffs requiring a review every four years. Most recently tariffs set by PDAM Sleman was in 2016 therefore it requires a recalculation. Besides that, it is necessary to analyze the tariff acceptance from the service provider and service recipient’s point of view. Calculation tariff method utilized a formula based on the Minister of Home Affairs Regulation No. 71 of 2016. Acceptance analysis conducted by calculating the projection of water sales revenue, the profit to earning assets ratio, and the willingness to pay (WTP) projection of customers. Revenue projections were obtained by multiplying tariffs with the water sold volume. The WTP projection is carried out using the inflation method based on the WTP of PDAM Sleman customers from the 2007’s research. PDAM Sleman tariffs based on calculations resulted low tariffs of IDR3727.48, basic tariffs of IDR4659.36, and full rate of IDR9460.17. Based on the WTP analysis, the tariffs are feasible from the the service recipient’s point of view, which are the PDAM customers, because it is still affordable by customers for their average water consumption. Nevertheless, from the point of view of the service provider, which is PDAM Sleman, the tariffs are not feasible because the profit ratio of 0.31% is still much lower than the fairness profit ratio as 10% amount. Therefore, it is necessary to make tariff adjustments to increase profits. The adjustment strategies such as by determined tariffs only based on consumption blocks without breaking down based on customer group categories and adjusting the range of second and third consumption blocks.

Efficiency of applying urea and UTEC carbamide on rice crops

The high efficiency of UTEC carbamide (modified NBPT – N-(n-butyl) thiophosphoric triamide carbamide) is experimentally proven basing on analysis of the dynamics of the ammonium nitrogen content in the meadow soil of rice irrigation systems of Krasnodar region and the urease activity, the nitrogen consumption by rice plants, yield, nitrogen yield removal and its utilization from fertilizer. Different schemes of applying nitrogen fertilizer are assessed. It is shown that when applying nitrogen fertilizer at a full rate in one step, it is necessary to give preference to UTEC carbamide; with fractional UTEC application, it is advisable to apply before sowing and as top dressing in germination phase, the second UTEC carbamide fertilization is less effective than that with urea; with a 20% reduction in the UTEC carbamide application rate, a yield comparable to that under the traditional scheme and rate of urea application is formed; the greatest ecological and agrochemical effect is achieved with the following fertilization system: before sowing – ammophos 100 kg/ha (N12P52) + UTEC carbamide 120 kg/ha (N55); 1st top dressing (germination) – UTEC carbamide 100 kg/ha (N46); 2nd top dressing (tillering) – urea 80 kg/ha (N37).

Traffic capacity improvement factor when VAMOS technique is applied

New modern technologies in mobile telephony overcome the possibilities of GSM systems. VAMOS technique is one way to improve traffic properties of traditional GSM systems. Our aim is to analyze the level of this improvement achieved by VAMOS implementation. The number of traffic resources is doubled, but it is proved that traffic capacity is more than doubled for full rate connections implementation and more than quadrupled for half rate connections regardless of offered traffic for all values of emission power difference between 4dB and 10dB when considering two paired subchannels. There are two loss types in VAMOS systems: unpairing loss and traffic loss when all subchannels are busy. The values of these two loss types whose sum presents the total loss in VAMOS systems are determined by originally developed simulation program. The achievable total loss may be decreased for 45% or even more when allowable power difference between paired channels is increased from 4dB to 10dB.

Combined Use of PGPR and Reduced Rates of Azoxystrobin to Improve Management of Sheath Blight of Rice

Farmers heavily rely on the use of strobilurin fungicides to manage sheath blight (ShB) caused by Rhizoctonia solani AG1-IA, the most important disease in rice in the southern United States. Greenhouse and field studies were conducted to evaluate the potential use of plant growth-promoting rhizobacteria (PGPR) in combination with a reduced rate of azoxystrobin as a strategy to improve the current fungicide-reliant management. Of the nine antagonistic PGPR strains screened in the greenhouse, Bacillus subtilis strain MBI600 provided the most significant and consistent suppression of ShB. Efficacy of strain MBI600 was further evaluated at the concentrations of zero, 103, 106, 109, and 1011 CFU/ml alone or in combinations with zero, 17, 33, 50, 67, 83, and 100% of the recommended rate (0.16 kg a.i./ha) of azoxystrobin. Strain MBI600 applied at 106,109, and 1011 CFU/ml alone was effective in reducing ShB severity. Combinations of this strain at these rates with 33% or more of the recommended rate of azoxystrobin further reduced ShB severity. A dose response model defining the relationships between strain MBI600, azoxystrobin, and ShB severity was established. Estimates of the effective concentrations, EC50 and EC90, of strain MBI600 when applied in combination with 50% of the recommended rate of azoxystrobin were 104 and 109 CFU/ml, respectively. A field trial was conducted over 4 years to verify the efficacy of their combinations. Strain MBI600 alone, when applied at 109 CFU/ml at the boot stage, reduced ShB severity but did not significantly increase grain yields each year. Combination of strain MBI600 with azoxystrobin at the half-recommended rate improved efficacy of strain MBI600, reducing ShB severity to a level comparable to that of azoxystrobin applied at the full rate in all four years. The combined treatment also increased grain yield by 14 to 19% comparable to the fungicide applied at the full rate in 3 of 4 years. Combined use of PGPR strain MBI600 with a reduced rate of azoxystrobin can be a viable management option for control of ShB while allowing producers to use less fungicide on rice.