Pemurnian Glukoamilase Dari Hasil Fermentasi Kapang Rhizopus Oryzae

Purification of the glucoamylase R. oryzae was carried out by addition of ammonium sulfate 80% saturation, on the fermentation broth at 4°C. The precipitate formed by centrifugation at 9000 rpm was then dialyzed in buffer solution and then concentrated using freeze dryer. It was found that the specific activity of the enzyme was around three-fold higher the crudeenzyme from fermentation broth and the purity of the enzyme was almost twelve-fold.purer than the crude enzyme. The molecular weight of the glucoamylase was found to be 36,000 as determined by SDS gel electrophoresis. The optimum pH witli soluble starch as substrate was at pH 4.5 and the optimum temperature was 55°C while the Km Value was 0.027%

Extensive 1-year survey of trace elements and compounds in the airborne suspended particulate matter in Cleveland, Ohio

Concentrations of 75 chemical constituents in the airborne particulate matter were measured in Cleveland, Ohio, during 1971 and 1972. Values covering a 1-year period (45 to 50 sampling days) at each of 16 sites are presented for 60 elements. A lesser number of values is given for sulfate, nitrate, fluoride, acidity, 10 polynuclear aromatic hydrocarbon compounds, and the aliphatic hydrocarbon compounds as a group. Methods used included instrumental neutron activation, emission spectroscopy, gas chromatography, combustion techniques, and colorimetry. Uncertainties in the concentrations associated with the sampling procedures, the analysis methods, the use of several analytical facilities, and samples with concentrations below the detection limits are evaluated in detail. The data is discussed in relation to other studies and source origins. The trace constituent concentrations as a function of wind direction are used to suggest a practical method for air pollution source identification

Model Penerapan Algoritma Ant Colony Optimization (Aco) Untuk Optimasi Sistem Informasi Penjadwalan Kuliah

Penjadwalan kuliah merupakan proses yang sangat kompleks, karena harus mengatur beberapa komponen seperti dosen, matakuliah, kelas, ruang dan waktu dengan memperhatikan sejumlah batasan dan syarat (constraint) tertentu. Dalam proses pembuatan jadwal kuliah ini setiap perguruan tinggi masing masing berbeda syarat dan batasan. Hal ini lah yang menyebabkan banyak dilakukan penelitian terkait optimasi penjadwalan kuliah. Perlunya optimasi penjadwalan kuliah dirasakan juga oleh program studi manajemen yang merupakan salah satu program studi di Universitas Komputer Indonesia dengan jumlah mahasiswa yang banyak. Dalam proses penjadwalan kuliah masih dilakukan secara konvensional sehingga sering terjadi bentrok jadwal dan prosesnya membutuhkan waktu yang lama. Dalam penggambaran sistem ini menggunakan metode pendekatan berorientasi objek dengan alat bantu pemodelan UML (Unified Modeling Language) dan menggunakan metode pengembangan sistem model prototipe sebagai acuan tahapan penelitian. Penelitian ini merupakan tahap awal dalam membangun sistem informasi penjadwalan kuliah. Hasil penelitian ini berupa model penerapan algoritma Ant Colony Optimization (ACO) untuk optimasi sistem informasi penjadwalan kuliah

Preliminary analysis of an extensive one year survey of trace elements and compounds in the suspended particulate matter in Cleveland, Ohio

Beginning in 1971 a cooperative program has been carried on by the City of Cleveland Division of Air Pollution Control and NASA Lewis Research Center to study the trace element and compound concentrations in the ambient suspended particulate matter in Cleveland Ohio as a function of source, monitoring location and meteorological conditions. The major objectives were to determine the ambient concentration levels at representative urban sites and to develop a technique using trace element and compound data in conjunction with meteorological conditions to identify specific pollution sources which could be developed into a practical system that could be readily utilized by an enforcement agency

Analysis of transmission lightning arrester locations using Tflash

Tropical countries with extensive lightning activity, such as Malaysia, encounter numerous problems on their electrical transmission and distribution systems. Many overhead lines trip because of back flashover of lightning and shielding failures of the grounding system. To overcome the problem and improve transmission line performance, a detailed lightning study is required to analyse the corresponding lines and determine the best location for transmission line arrester (TLA) installation. We used TFlash to analyse a TLA installation on a 132-kV SSWW-BBST overhead transmission line system located in Selangor, Malaysia. Based on the results, the installation of the TLA at the optimum quantity and at appropriate towers have reduced the number of lines that trip

Lattice Boltzmann method based study of the heat transfer augmentation associated with Cu/water nanofluid in a channel with surface mounted blocks

The study of the forced convection in a channel has many practical applications. In this paper, the forced convection heat transfer from surface mounted blocks attached to the bottom wall of a horizontal channel with nanofluid is numerically studied by the second-order lattice Boltzmann method (LBM). The effects of Reynolds numbers and geometrical parameters of the blocks in different aspect ratios on the flow field and temperature distribution for various volume fractions of nanofluid (φ = 0, 0.01, 0.03 and 0.05) are analyzed. Also, the influence of these parameters is investigated on the local and average Nusselt numbers. It is concluded that heat transfer in channels can be enhanced by using the block on the walls and adding nanoparticles. There is a maximum value of 39.04% increase in average heat transfer coefficient for all the examined cases compared to the base fluid (i.e., water)

Transmission-Lightning-Arrester : A Location Determination Using Tflash

The high density of lightning occurrence in Malaysiahas caused problems to transmission and distribution electricalenergy. Normally, transmission overhead lines trip due to BackFlashover (BF) of lightning and shielding failures of earth wire.Therefore, a detailed lightning study is required to analyse thecorresponding lines and to determine the exact location ofTransmission Lightning Arrester (TLA). In this paper, a simulationof lightning study using TFlash software associated with theinstallation of (TLA) at 132 kV SSWW-BBST overhead linessystem located in Selangor, Malaysia is presented. By using theTFlash software the location of TLA has been determine

Generating Electricity using PV/FC Hybrid System

A reliable electrical energy supply is a prerequisitefor improving the standard economic and quality of life levels in acountry. As is the case in many countries, it is uneconomical toconnect these villages to the existing grid, the installation of standaloneelectrical power generators has become common practice. Asa result, diesel stand-alone power generators see widespread use inthese remote locales, which, whilst fit for their intended purpose,unfortunately suffer from several drawbacks, including instabilityin regards to everyday oil prices and a number of environmentalissues. The implementation of a PV/FC hybrid power system couldbe one potential alternative to help solve these problems. Therefore,this paper presents PV/FC system control strategies. This study isespecially important in terms of envisioning the future energysupply needs. By using HOMER the proposed control strategiesand suggested components of a PV/FC system would be able toproduce a satisfactory outcome

An Experimental Determination of Thermal Conductivity and Electrical Conductivity of Bio Glycol Based Al2O3 Nanofluids and Development of New Correlation

Nanofluid, as a kind of new engineered material consisting of nanometer-sized additives and base fluids, has attracted great attention from investigators for its superior thermal properties and many potential applications. In this paper, the thermal conductivity, dispersion stability and electrical conductivity of 100% bioglycol (BG) based nanofluids containing Al2O3 nanoparticles were studied in a temperature range of 30 to 80 °C. Nanofluids with 0.1, 0.3, 0.5, 0.7, and 1% volume concentrations were prepared using the two-step method without using surfactant. The nanofluids demonstrated excellent stability over this temperature range after using long-term sonication. A new correlation has been developed for the thermal conductivity of nanofluids as a function of temperature and particle volume concentration. This study also revealed that the thermal conductivity enhancement of bio glycol (BG), ethylene glycol (EG) and propylene glycol (PG) of 1.0% volume concentration at 30 °C was 17%, 9% and 3.6% respectively. However, the increment in temperature reacts inversely to the thermo-electrical conductivity (TEC) ratio. The maximum value of TEC is 9.5 at 0.5% volume concentrations and temperature of 30 °C