Modeling and Prediction of the Uniformity of Spray Liquid Coverage from Flat Fan Spray Nozzles

The effectiveness and quality of agricultural spraying largely depends on the technical efficiency of the nozzles installed in agricultural sprayers. The uniform spraying of plants results in a decrease in the amount of pesticides used in agricultural production and affects environmental safety. Both newly developed sprayers and those currently in use need quality control as well as an assessment of the performance of the spraying process, especially its uniformity. However, the models applied presently do not ensure accurate estimates or predictions of the spray liquid coverage uniformity of the treated surface. Generally, the distribution of the atomized liquid quantity is symmetrical and leptokurtic, which means that it does not fit well to the commonly used standard distribution. Therefore, there is a need to develop and design new tools for the evaluation, modeling, and prediction of such a process. The research problem studied in the present work was to find a new model for the distribution of atomized liquid quantity that could provide capabilities better than have been available so far to assess and predict the spraying process results. The research problem was solved through the formulation of a new function for the probability density distribution of sprayed liquid accumulation on the surface of the preset dimension size. The development of the new model was based on the results from a series of water atomization tests with an appropriate measurement device design based on the widely applied flat fan nozzles (AZ-MM type).

PENGARUH PROFITABILITAS, LEVERAGE DAN KEPEMILIKAN INSTITUSIONAL TERHADAP KEBIJAKAN DIVIDEN

Penelitian ini bertujuan untuk melakukan eksplorasi terhadap faktor pengaruh kebijakan dividen yang terjadi pada perusahaan yang tergolong Liquid Quantity 45 (LQ 45) dari tahun 2009-2012 terdaftar pada Bursa Efek Indonesia. Dalam mengumumkan kebijakan dividen biasanya dipengaruhi oleh beberapa faktor antara lain profitabilitas, leverage dan kepemilikan institusional. Metode penelitian yang digunakan adalah metode kuantitatif dengan teknik analisis regresi linear berganda. Variabel bebas dalam penelitian ini adalah profitabilitas yang diproksikan dengan return on asset, leverage yang diproksikan dengan total debt to total asset dan kepemilikan institusional yang diukur dengan persentase kepemilikan saham institusi. Variabel dependen ini adalah kebijakan dividen yang diproksikan dengan dividend yield yaitu tingkat pendapatan/yield berupa dividen yang diperoleh dari investasi terhadap per lembar saham perusahaan. Adapun populasi dalam penelitian ini berjumlah 45 perusahaan dengan sampel sebanyak 15 perusahaan. Hasil penelitian berdasarkan pada uji signifikan parsial (uji t) yaitu nilai Sig masing-masing 0,000 menunjukan bahwa profitabilitas dan leverage berpengaruh positif dan signifikan terhadap kebijakan dividen. Sedangkan kepemilikan institusional memiliki nilai 0,157 yang diindikasikan tidak berpengaruh. Dari hasil uji koefisien determinasi diperoleh nilai R2 sebesar 0,772. Hasil uji F bernilai Sig 0,000 yang menunjukkan bahwa variabel yang digunakan dalam penelitian ini secara simultan berpengaruh terhadap variabel dependen. Kata kunci: Kebijakan Dividen, Profitabilitas, Leverage, Kepemilikan Institusional.

THE INFLUENCE OF COOLING AND LUBRICATION LIQUID QUANTITY ON THE ISOTROPY OF A MACHINE COMPONENT SURFACE DURING MACHINING

This paper presents an initial verification of the influence of a cooling- -lubrication liquid or its lack on the geometric surface structure of machine components undergoing the process of machining. It has been proposed to use the degree of isotropy of the finish surfaces, apart from commonly used roughness parameters, for the evaluation of changes in the quality of components machined in different cooling and lubrication conditions. In this study, the usefulness of the degree of isotropy for a description of the surface geometric structure characteristics has been verified.

Research on Microbial Degradation of Bamboo Lignin for Extraction of Natural Bamboo Fiber

This study optimizes on the technological conditions for extraction of natural bamboo fiber by means of microbial degradation of bamboo lignin. Results show that by the orthogonal experiment, we have studied out optimal conditions for combining three strains with fermentation to produce enzyme: 10.0 g/L glucose, 0.2 g/L ammonium tartrate, 4.5 buffer solution pH value and 20.0/250 ml loading liquid quantity. In these above four factors, the primary and secondary factors affecting enzyme production are: carbon source > pH value > loading liquid quantity > nitrogen source. Meanwhile, the experiment has studied the influence of single factor on lignin degradation: at the temperature of 37 °C, about 4 x 107spore concentration, adding 1.5 mg/L veratryl alcohol and introducing air at the efflux rate of 1 L/min are bamboo crude fiber optimal conditions for microbial selective degradation of lignin.

Optimization on Process Parameters of Brewing Ganoderma lucidum Functional Drinking Vinegar

Through the biological reaction caused by self-detached acetic acid bacteria in the ganoderma lucidum deep fermented liquid, the process parameters of producing ganoderma lucidum functional drinking vinegar have been researched. Using the orthogonal experiment and the method of neural network, the nonlinear mapping model among the ganoderma lucidum functional drinking vinegar's process parameters has been established. Through the optimization, the best process parameters were: ethanol quantity was 6.7±0.2%, ganoderma lucidum liquid quantity was 32±1%, reaction time was 74h, inoculum concentration of acetic acid bacteria was 10%.