Simple Laboratory Scale Research Articles

Design and Study of Simple Biogas Reactor using Kitchen Waste Within the Habitat of Federal Polytechnic of Oil and Gas Bonny Island, Rivers State, Nigeria

This research work is about design and study of simple biogas reactor using Kitchen Waste within the habitat of Federal Polytechnic of Oil and Gas Bonny Island, Rivers State, Nigeria to produce gas. The objective of the work is to collect and measure the amount of waste that is been generated within the study area as well as to construct a simple laboratory scale biogas reactor and using the kitchen waste as substrate and measure the amount of gas that is been generated from biogas reactor per day. Based on the objective for this research a biogas digester was designed. Two experiments was carried out to determine the extent of production of biogas and the duration required so as to determine the rate of formation of biogas. In experiment one, dissimilar kinds of biomass like rice, potato, green leaves, sugar in different amounts were mixed with cow dung and rice husk to prepare 4 samples to determine the maximum generation of biogas through fermentation process. The gas is collected in balloons and they were measured to determine the amount of gas produced in each sample. The extent to which the blowing of balloons took place determined the quantity of gas evolved in each of the incumbent samples. In experiment two, we have used two 5lt. bottles in which the amount of cow dung used varies while same amount of kitchen waste mixture was utilized. The process and conditions for trapping and analyzing the gas is the same as in experiment one. From this experiment the rapidness of formation of biogas was observed. The experimental analysis carried out also gives us a clear idea of the indulgence of materials with respect to their combination to deferring extent of concentration to deliver optimum generation of biogas, in particular methane thereby unveiling us to develop an imminent and high performance derivative affordable biogas reactor.

Applicability of the electrocoagulation process in treating real municipal wastewater containing pharmaceutical active compounds.

In this study, the viability of using electrocoagulation process as a method for pharmaceuticals removal from real municipal wastewater was demonstrated. Batch experimental runs were performed using a simple laboratory scale electrochemical reactor with aluminium and stainless steel as anode and cathode, respectively. Diclofenac (DCF), carbamazepine (CBZ) and amoxicillin (AMX) were selected as representative of pharmaceuticals frequently detected in the aquatic environment. The effects of varying experimental parameters namely current density (0.3, 0.5 1.15 and 1.8 mA cm-2), initial pharmaceutical concentration (0.01, 4 and 10 mg L-1), electrolysis duration (3, 6 and 19 h) and application mode (continuous vs. intermittent) on pharmaceutical removal efficiencies were evaluated. High pharmaceutical abatement was recorded at elevated current density and prolonged electrolysis duration due to additional electro-generated coagulant species in solution.

Comparison of Drying Characteristics of Green and Black Seedless Grapes using Hot Air Dryer

Drying characteristics of Thompson seedless (Green) and Sharad seedless (Black) grapes were obtained using a simple laboratory scale hot air dryer. Grapes were dipped for three minutes in a solution prepared by adding 25 g Potassium carbonate and 15 mL Ethyl oleate to 1 liter of distilled water maintained at a temperature of 40°C. Grapes were dried using hot air at a temperature of 60°C and a flow rate of 0.82 mls created by chimney effect. Green grapes with an initial moisture content of 79.94 % required 19 hrs while Black grapes with an initial moisture content of 81.38 % required 27 hrs to reach a final moisture content of 18 % (wet basis). Drying rate constant value for Green grapes was 0.036505 h<sup>-1</sup> while that for Black grapes was 0.024793 h<sup>-1</sup> . Raisins produced from both variety grapes possessed all the required quality parameters acceptable in the international market.

Performance assessment of thermal sensors during short-duration convective surface heating measurements

The determination of convective surface heating is a very crucial parameter in high speed flow environment. Most of the ground based facilities in this domain have short duration experimental time scale (~milliseconds) of measurements. In these facilities, the calorimetric heat transfer sensors such as thin film gauges (TFGs) and coaxial surface junction thermocouple (CSJT) are quite effective temperature detectors. They have thickness in the range of few microns and have capability of responding in microsecond time scale. The temperature coefficient of resistance (TCR) and the sensitivity are calibration parameter indicators that show the linear change in the resistance of the gauge as a function of temperature. In the present investigation, three of types of heat transfer gauges are fabricated in the laboratory namely, TFG made out of platinum, TFG made out of platinum mixed with CNT and chromel–alumel surface junction coaxial thermocouple (K-type). The calibration parameters of the gauges are determined though oil-bath experiments. The average value TCR and sensitivity of platinum TFG is found to be 0.0024 K−1 and 465 μV/K, while similar values of CSJT are obtained as, 0.064 K−1 and 40.5 μV/K, respectively. The TFG made out of platinum mixed with CNT (5 % by mass) shows the enhancement of TCR as well as sensitivity and the corresponding values are 0.0034 K−1 and 735 μV/K, respectively. The relative performances of heat transfer gauges are compared in a simple laboratory scale experiment in which the gauges are exposed to a sudden step heat load in convection mode for the time duration of 200 ms. The surface heat fluxes are predicted from the temperature history through one dimensional heat conduction modeling. While comparing the experimental results, it is seen that prediction of surface heat flux from all the heat transfer gauges are within the range of ±4 %.

Chipping fracture resistance of denture tooth materials

ObjectiveThe applicability of the edge chipping method to denture tooth materials was assessed. These are softer materials than those usually tested by edge chipping. The edge chipping fracture resistances of polymethylmethacrylate (PMMA) based and two filled resin composite denture tooth materials were compared. MethodsAn edge chipping machine was used to chip rectangular blocks and flattened anterior denture teeth. Force versus edge distance data were collected over a broad range of forces and distances. Between 20 and 65 chips were made per condition depending upon the material, the scatter, and the indenter type. Different indenter types were used including Rockwell C, sharp conical 120o, Knoop, and Vickers. The edge toughness, Te, was evaluated for different indenter types. ResultsThe edge chipping data collected on the blocks matched the data collected from flattened teeth. High scatter, particularly at large distances and loads, meant that many tests (up to 64) were necessary to compare the denture tooth materials and to ascertain the appropriate data trends. A linear force–distance trend analysis was adequate for comparing these materials. A power law trend might be more appropriate, but the large scatter obscured the definitive determination of the precise trend. Different indenters produce different linear trends, with the ranking of: sharp conical 120o, Rockwell C, and Knoop, from lowest to highest edge toughness. Vickers indenter data were extremely scattered and a sensible trend could not be obtained. Edge toughness was inversely correlated to hardness. SignificanceEdge chipping data collected either from simple laboratory scale test blocks or from actual denture teeth may be used to evaluate denture materials. The edge chipping method's applicability has been extended to another class of restorative materials.

Preparation of glibenclamide nanocrystals by a simple laboratory scale ultra cryo-milling

The objective of this study is to evaluate the ability to reduce the particle size of glibenclamide (GBC) to the nanometric scale through a very simple and well-known laboratory scale method, the laboratory scale ultra cryo-milling. The effect of milling on GBC crystalline properties and dissolution behaviour was deliberately evaluated in the absence of any surfactants as stabilizers. The milling procedure consisted in adding particles to liquid nitrogen and milling them by hand in a mortar with a pestle for different time intervals (15, 30, 40 min). For comparison, the same milling procedure was also applied without liquid nitrogen. The particle size reduction was evaluated for the coarsest samples (>3 μm) by measuring the particle Ferret’s diameter through scanning electron microscopy, while for the smallest one (<3 μm) by dynamic light scattering. A time grinding of 40 min in the presence of liquid nitrogen was revealed highly efficacious to obtain particles of nanodimensions, with a geometric mean particle size of 0.55 ± 0.23 μm and more than the 80 % of particles lower than 1,000 nm. Interestingly, non-agglomerated particles were obtained. Differential scanning calorimetry and X-ray powder diffractometry allowed to assess that under mechanical treatment no polymorphic transitions were observed, while a decrease in crystallinity degree occurred depending on the milling procedure (presence or absence of liquid nitrogen) and the milling time (crystallinity decreases at increasing milling time from 15 to 40 min). A comparison of the intrinsic dissolution rate and the dissolution from particles revealed an interesting improvement of particle dissolution particularly for particles milled in the presence of liquid nitrogen due to an increase in particle surface area and concentration gradient, according to the Noyes–Whitney equation.

An alternative structure for next generation regulatory controllers. Part II: Stability analysis, tuning rules and experimental validation

We recently developed, as an alternative to the PID controller, a novel 4-mode control scheme that takes full advantage of modern electronic hardware components, and whose tuning parameters are directly related to controller performance attributes (robustness, set-point tracking, and disturbance rejection); its achievable performance is better than that of the PID controller, and it can be designed and implemented much more directly and transparently. In this companion paper we present robust stability results for the proposed controller, for any given plant/model mismatch; these results are then used to generate simple tuning rules for the controller. The effect of noise on controller performance is explicitly considered and modified tuning rules are proposed for excessively noisy processes. The controller tuning results and procedure are then illustrated via experimental testing and validation. First, water level control in a simple laboratory scale process is used to illustrate the design, tuning, and implementation of the RTDA controller. We use this process primarily to evaluate the controller performance and illustrate how the tuning parameters influence, directly and independently, the controller performance attributes. The controller is then implemented on a pilot-scale physical vapor deposition process to demonstrate its performance on a more complicated process that is prototypical of 21st century manufacturing. We demonstrate that the proposed controller achieves improved performance with minimal tuning effort.

Laboratory scale studies on mitigation of high 222Rn concentrations in air and water

In view of the occasional occurrence of high 222Rn concentrations in air and water under certain circumstances, and in view of the potential health hazards of increased levels of 222Rn in respirable air and in potable water, mitigation of such high 222Rn concentration has become of primary concern. To facilitate the study of the efficiency of the various 222Rn mitigating factors simple laboratory systems were used. Altered alkali granite was used as radon source to enrich air and a piece of pitchblende was used as radon source to enrich water samples. Both enriched media will then be subjected to the mitigation treatments. Charcoal canister technique along with gamma spectrometry were used to measure 222Rn concentrations in air before and after the different mitigating treatments. These were: use of ventilation, radon barriers such as geo-membranes and aluminum sheet, and sealant such as epoxy and vinyl tape. Regarding high levels of 222Rn in air ventilation was the most efficient mitigating factor. Standard liquid scintillation counting was used to measure 222Rn concentrations in water before and after the different mitigation treatments. These were: use of aeration, activated charcoal and heating. Regarding high levels of 222Rn in water, aeration using bubblers and large volume of air was most effective in removing radon from water in a short time. However all the mitigating factors proved effective, in different degrees in decreasing 222Rn concentrations in the respective media. The result from these studies are in general agreement with reports in the literature. It can be concluded then that the different 222Rn mitigating factors can be tested and compared effectively under controlled conditions using simple laboratory scale systems.

Synthesis and characterisation of La 1−xMnO 3± δ nanopowders prepared by acrylamide polymerisation

La 1−xMnO 3± δ (x=−0.02 to 0.35) nanocrystalline powders were prepared by a new sol–gel method. It is used the acrylamide gelification to form an organic 3D tangled network where a solution of the respective cations is soaked. This method was adapted to cover a broad range of high impact electro–ceramic oxides, which a particular example is the CMR nanopowders reported in this work. The acrylamide sol–gel process is a fast, cheaper and easy to scale-up method for obtaining fine powders of complex oxides. This synthesis method allows performing 100 g of highly pure nanopowders in one run with simple laboratory scale. The sponge like powder obtained consists of thin sheets composed of nanocrystallites whose size varies from 66 nm to 30 nm, depending on composition. The oxygen content of the manganite powder is shown to decrease with vacancy-doping on lanthanum site. Such a evolution can be explained for La/Mn<0.9 by considering a demixtion of the powder into La 0.9MnO 3 and Mn 3O 4 phases, while for La/Mn>0.9, the high oxygen excess leads to consider vacancies on both lanthanum and manganese sites. Both hypotheses are supported by magnetic measurements, which show a constant Curie temperature of 295 K for La/Mn<0.9, while for La/Mn>0.9, the occurrence of vacancies on manganese sites progressively impedes the ferromagnetic interactions, leading to a cluster–glass behaviour in the case of the highly manganese-deficient La 0.94Mn 0.92O 3 compound.

A Simple Laboratory Scale Method for Isolation of Amaranth Starch

AbstractStarch was isolated from the seeds of Amaranthus hypochondriacus and Amaranthus cruentus by two established methods and a new simpler method involving steeping in dilute alkali, neutralization, and ambient air drying without using expensive or highly hazardous chemicals. The latter is recommended for isolating amaranth starch for human food uses on a laboratory scale.

Imaging of subsurface faults by walkaway VSP waveguiding

Hydrocarbon reservoirs sometimes occur within low velocity channels, thus forming potential seismic waveguides. The waveguide might be excited at its discontinuities (faults) by seismic waves travelling downward from a surface source. Given that a waveguide would confine scattered energy to the horizontal plane, it should be possible to map fault scatterers at large range by means of a downhole triaxial geophone placed within the reservoir. A simple laboratory scale seismic model of a Southern North Sea gas reservoir was constructed to study the problem. Multicomponent seismic measurements were taken in both walkaway VSP and offset VSP shooting geometries. The results validate the presence of strong waveguiding in a low velocity layer disrupted by faulting. The diffracted arrivals can be imaged to locate the fault 'source'. The model results, when scaled to the field situation, suggest that faults within a reservok can be detected at horizontal distances greater than several kilometres from the drill hole.

Studies on Small Scale Testing Compared to Cal 133 Mockup Test: Part II

Development of a simple laboratory scale ignition test to serve as a quality control tool in conjunction with larger scale tests such as California Technical Bulletin 133 has been continued. Using the California Technical Bulletin 117 configuration the proposed foam test procedure uses a lightweight standard polypropylene fabric and an igni tion source of a 55 ml cube of 160 kg/m3 density rigid foam. Alternatively the procedure may be useful in screening fabrics and in nerliners with an appropriate foam. Main criteria are burn time and weight loss.

Status Report: Studies on Small Scale Testing Compared to Cal 133 Mockup Test

This study was triggered by the need for a simple laboratory scale ignition test to serve as a Quality Control Tool in conjunction with larger scale tests. Using the basic California Bulletin 117 (Cal 117) smoldering test configura tion, a number of variables have been screened in a composite ignition scenario to determine the feasibility of correlating with California Bulletin 133 (Cal 133) results. Variables studied included ignition source intensity (7), fabrics (6), and foams (6 types) ranging from standard furniture to high (flammability) per formance types. Results to date indicate feasibility of this approach.

Ejecta pulsing of subscale solid propellant rocket motors

This paper presents results obtained in a program designed to develop guidelines for pulsing solid propellant rocket motors to determine their susceptibility to finite amplitude disturbances. A series of motor firings was conducted in which sphetes of different sizes and materials were ejected through the nozzle to simulate inf light partial nozzle blockage due to igniter, propellant or other combustion chamber material fragments. Simple laboratory scale solld rocket motors with full and partial length grains were utilized. All of the motors tested were triggered into sustained nonlinear instability. A simple analysis was developed to calculate the velocity of the ejecta and pulse duration. Gaod ogreement between predicted and measured pulse durations was obtained. Two methods were developed for predicting initial ejecta induced pulse amplitudes: a simple model based on linear wave propagation theory and the assumption of quaslsteady nozzle behavior, and a numerical model which utillzes the quasi-steady nozzle assumption to provide a nozzle entrance boundary condition to a comprehensive combustion chamber nonlinear instability analysis. Comparisons of theoretical predictions with experimental data for both pulse amplitude and the motor response to pulsing are presented. Tht nonlinear instability analysis was found to be capable of predicting the complete range of nonlinear behavior observed in motor response to ejecta pulsing. Good agreement between measured and predicted initi pulse (amplitude and harmonic content), waveform evo ution, growth and decay rates, and DC shift was obtained. p'

A laboratory scale chill-casting vacuum induction furnace

The details of the construction and operation of a simple laboratory scale induction furnace with a capacity of approximately 3 cm3, which may be used at either low pressures (10-4 mm of mercury) or with an inert atmosphere is described. The furnace and induction unit are fitted to a tilting frame allowing the melt to be cast into a copper mould. Copper, silver, gold, magnesium and cadmium based alloys have been cast successfully with this apparatus.