The Use of Mathematical Model to Predict Levels of N and K for Optimum Yield

Sometimes, yield from a commercial plantation is reduced because of inadequate availability of fertilisers to the plant due to various reasons such as poor quality of fertilizers used, loss of fertilizers in the field during cultivation due to natural causes etc. One way of preventing such loss in yield is to apply remedial fertiliser doses in the field in an intermediate stage of cultivation. To implement such a method effectively, a mathematical model has been proposed in this work. The model first determines the amount of fertilisers needed at the beginning of cultivation to optimize yield. It then ascertains at an intermediate stage of cultivation whether the plant receives adequate fertilisers for producing optimum yield. In case it is found out that required fertilisers are not available to the plant, the model decides how much more remedial fertilizer doses should be applied at the intermediate stage so that yield will not be affected. A potato plantation has been considered to illustrate the applicability of the proposed mathematical model.

Utilization of oil palm empty fruit bunches biomass through slow pyrolysis process

The agricultural sector produces solid waste biomass abundantly. However, this biomass potential has not been utilized optimally. Indonesia as the world’s number one producer of oil palm plantations produces enormous biomass potential. Oil palm empty fruit bunches (EFB) are the largest solid waste with a fraction of around 20-23% of fresh fruit bunches. Conventionally, it is only used as plant mulch in plantations areas. However, this biomass can still provide added value to bioenergy products through thermochemical pyrolysis conversion. The study was conducted with EFB raw materials that have been chopped with a size of <2mm, heating rate of 10C/minute with temperature variations of 350°C, 400°C, 450°C, 500°C, and 550°C. The results showed that the EFB pyrolysis at low temperatures produced biochar products, and at high temperatures, it produced maximum product in the form of bio-oil. In the EFB pyrolysis process, biochar with an optimum yield of 36.92% was produced at 350°C, and bio-oil with an optimum yield of 46.60% was produced at a temperature of 550°C.

Multiple Regressions Analysis to investigate the optimal yield of Guava fruits at different level of NPK Fertilizers in south west Nigeria

Purpose: This study investigates the effect of fertilizers (Nitrogen, Phosphorus & Potassium) on Guava; examines which of the three elements of NPK contribute most to the weight of guava seed. It thus further determines at what proportion each of the three elements is to be applied for optimum yield. Subjects and Methods: A 3 x 3 factorial experiments were adopted in the data analysis; further tests were conducted using different Post Hoc test approaches and a multiple regression analysis was derived to investigate at what proportion the elements are to be applied for optimum yield. Results: The results of the analysis of variance (ANOVA) showed that only Phosphorus and Potassium contribute to the growth and weight yield of guava. The Post-Hoc Tests showed that there was a significant difference between the mean pair of P0 & P20 and P0 & P40 with a p-value of 0.000 and 0.000 respectively. Also, there was a significant difference between the mean pair of K0 & K50 and K0 & P100 with a p-value of 0.004 and 0.008 respectively which is less than the significant level at 0.05. Furthermore, the overall multiple regression models for the weight yield of guava fruits were obtained as: (Y)=5.646+0.0556N-0.3611P+1.5694K+1.7167NP+1.1333NK+1.0361PK. Conclusion: Thus, to obtain an optimal yield of 12- 20t/ha of guava fruits, phosphorus and potassium are to be applied at 40k.g and 50kg respectively with spacing of 6 x 6m accommodating 277.7 plants per hectare.

Production of Biodiesel from Desert Date Seed Oil Using Heterogeneous Catalysts

In the recent time, there is increasing research in the area of alternative fuels as the exhausts of presently used petroleum-based fuels have been identified to have negative effects on the environment. Fuels produced from plant oils and animal fats have the tendencies of replacing petro fuels since they are renewable in nature. One of these renewable fuels is biodiesel. However, the homogenous catalyst used in biodiesel production has some drawbacks such as difficulty in separation from the fuel, soap formation and corrosiveness of the product mixture. In this work, the use of heterogeneous catalyst sourced from local raw materials (kaolin and eggshell) for the production of biodiesel from oil of desert date seed has been investigated. The kaolin obtained from Alkaleri Mining Site, Bauchi, was calcined in an oven at 800 °C for 3 h. The calcined kaolin was then chemically activated. Also, the eggshell-based catalyst was produced from raw eggshells after washing, drying, grinding, sieving using 0.3 mm sieve size and calcining at 900 °C for 3 h. Furthermore, the oil content of the desert date seed, which was acquired from a local market in Bauchi, was extracted via solvent extraction in a laboratory with a yield of 42%. Then, the biodiesel was subsequently prepared by mixing the oil, methanol and catalyst in a flat bottom flask and heating the mixture for a specified period. The catalyst concentration, methanol to oil ratio and time of reaction were subsequently varied to obtain the best yield. The results obtained revealed that an optimum yield of 29% could be obtained at methanol to oil ratio of 6:1 and a reaction time of 60 min using 1.5 g of eggshell-based catalyst while an optimum yield of 22% was obtained with 0.6 g for kaolin-based catalyst at a reaction time of 60 min and methanol to oil ratio of 4:1. It is recommended that further work should be carried out to improve on the yield of the biodiesel obtained using the heterogeneous catalysts.

Comparison of CaO-NPs and Chicken Eggshell-Derived CaO in the Production of Biodiesel from Schinziophyton rautanenii (Mongongo) Nut Oil

The ever-increasing population growth and economic developments have heightened demand for energy. This has resulted in depletion and ever-rising prices of petroleum diesel, thus increasing environmental degradation. These complications have motivated this study for the search of an alternative eco-friendly and renewable source of energy such as biodiesel. Biodiesel has been found to be a potential alternative fuel for diesel. Biodiesel was produced by transesterification reaction of Schinziophyton rautanenii (mongongo) nut oil in the presence of a base heterogeneous catalyst: CaO derived from eggshell ash and synthesised CaO-nanoparticles (CaO-NPs). The catalysts were calcined at a temperature of 800°C for 3 h and characterized by scanning electron microscope-energy dispersive X-ray (SEM-EDX) where both catalysts showed agglomerated particles and high elemental composition of Ca and O. Powder X-ray diffraction (XRD) showed that CaO was present in both catalysts, and the average crystalline size obtained was 42 and 50 nm for CaO-NPs and eggshell ash, respectively. Fourier transmission infrared (FTIR) spectrometer showed absorption bands of CaO in both catalysts which were at 875 and 713.46 cm−1 for CaO-NPs and eggshell ash, respectively. The analysis of mongongo nut oil (MNO) and mongongo methyl esters (MMEs) was done according to the European biodiesel specification (EN 1421) and American Society for Testing and Materials (ASTM D675). Statistically, there was no significant difference between CaO-NPs and eggshell in terms of optimum yield ( P > 0.05 ) using a sample t-test. However, in terms of catalyst loading, the eggshell was a better catalyst as it required a low catalyst load to obtain an optimum yield of 83% at 6 wt.% compared to CaO-NPs with an optimum yield of 85% at 12 wt.%. The reactions were all performed at constant reaction conditions of 9 : 1 methanol to oil ratio, 3 h reaction time, and 65°C reaction temperature.

Transesterifikasi In Situ Minyak Biji Pepaya Menjadi Metil Ester dengan Co-Solvent N-Heksana Menggunakan Microwave

Dalam berat kering biji pepaya mengandung minyak hingga 30% sehingga berpotensi untuk digunakan sebagai bahan baku biodiesel. Transesterifikasi in situ merupakan langkah sederhana dalam menghasilkan biodiesel yaitu dengan cara mengeliminasi proses ekstraksi dan pemurnian minyak sehingga dapat menghemat biaya produksi dan memberikan hasil yang memuaskan. Reaksi satu fase dapat dibentuk dengan menambahkan co-solvent yang dapat meningkatkan kelarutan minyak. N-heksana merupakan co-solvent yang paling baik karena murah, tidak reaktif dan bertitik didih rendah (68oC) sehingga dapat dipisahkan secara co-distilasi bersama-sama dengan metanol. Gelombang mikro dapat merambat melewati cairan sehingga proses pemanasan akan berlangsung lebih efektif dan proses pembuatan biodiesel dapat dilakukan lebih singkat. Pada penelitian ini variasi daya yang digunakan adalah 30%, 50% dan 70% dari 399 watt serta waktu reaksi yaitu 2, 4, 6, 8 dan 10 menit. Hasil kemudian dianalisa menggunakan GC (Gas Chromatography). Didapatkan yield optimum sebesar 89,25% pada daya sebesar 70% dan waktu reaksi 8 menit. Yield optimum memiliki densitas sebesar 0,86 g/cm3 dan memiliki angka asam 0,28 mg KOH/g sampel. Hasil tersebut telah memenuhi SNI 7182:2015.In the dry weight of papaya seed oil contains up to 30%, so the potential to be used as raw material for biodiesel. Transesterification in situ is a simple step to produce biodiesel that is by eliminating extraction process and refining of oil so it can save on production costs and give satisfactory results. The reaction of one phase can be formed by adding a co-solvent to increase the solubility of oils. N-hexane is a co-solvent that is best because it is inexpensive, non-reactive and low boiling point (68°C) so that it can be separated by co-distillation with methanol. Microwave can propagate passed through the liquid so that the heating process will take place more effectively and the process of making biodiesel can be made shorter. In this study the variation of power used is 30%, 50% and 70% of 399 watts and the reaction time is 2,4,6,8 and 10 minutes. Results were analyzed by GC (Gas Chromatography). The optimum yield was 89.25% at 70% power and reaction time 8 minutes. The optimum yield has a density of 0.86 g / cm 3 and has an acid number of 0.28 mg KOH/g sample. These results have met the SNI 7182:2015.

Optimum Strength Distribution for Structures with Metallic Dampers Subjected to Seismic Loading

A key aspect of the seismic design of structures is the distribution of the lateral strength, because it governs the distribution of the cumulative plastic strain energy (i.e., the damage) among the stories. The lateral shear strength of a story i is commonly normalized by the upward weight of the building and expressed by a shear force coefficient αi. The cumulative plastic strain energy in a given story i can be normalized by the product of its lateral strength and yield displacement, and expressed by a plastic deformation ratio ηi. The distribution αi/α1 that makes ηi equal in all stories is called the optimum yield-shear force distribution. It constitutes a major aim of design; a second aim is to achieve similar ductility demand in all stories. This paper proposes a new approach for deriving the optimum yield-shear force coefficient distribution of structures without underground stories and equipped with metallic dampers. It is shown, both numerically and experimentally, that structures designed with the proposed distribution fulfil the expected response in terms of both damage distribution and inter-story drift demand. Moreover, a comparison with other distributions described in the literature serves to underscore the advantages of the proposed approach.