Press Plate Research Articles

Development of Locally Fabricated Honey Extracting Machine

An indigenous honey extracting machine was designed, fabricated and evaluated at the workshop of the department of Agricultural Technology, Federal Polytechnic, Ile-Oluji, Nigeria using locally available materials. It has the extraction unit, the presser, the honey collector and the frame. The harvested honeycomb is placed inside the cylindrical extraction unit with perforated holes. The press plate is then positioned on the honeycomb while the hydraulic press of 3 ton was placed on it and supported by the frame. The hydraulic press which is manually operated forces the oil out of the extraction chamber through the perforated holes into the honey collector positioned at the lowest part of the extraction chamber. The honey extracting machine has an average throughput of 2.59 kg/min and efficiency of about 91%. The cost of producing the honey extracting machine is NGN 31, 700: 00, thirty-one thousand, and seven hundred naira only or $70 at NGN 452.8 to a dollar. This cost is affordable to beekeepers and would-be honey entrepreneurs. The honey extracting machine is easy to operate and maintained without any complex technical know-how. This simple technology solves the challenge of honey extraction among our peasant farmers in Nigeria.

Assessment of microbial bioburden on portable medical equipment in a hospital setting.

Although routine disinfection of portable medical equipment is required in most hospitals, frontline staff may not be able to disinfect portable medical equipment at a rate that adequately maintains low bioburden on high-use equipment. This study quantified bioburden over an extended time period for two types of portable medical equipment, workstations on wheels and vitals machines, across three hospital wards. Bioburden was quantified via press plate samples taken from high touch surfaces on 10 workstations on wheels and 5 vitals machines on each of 3 medical surgical units. The samples were taken at three timepoints each day over a 4-week period, with random rotation of timepoints and portable medical equipment, such that frontline staff were not aware at which timepoint their portable medical equipment would be sampled. The mean bioburden from the different locations and portable medical equipment was estimated and compared with Bayesian multilevel negative binomial regression models. Model estimated mean colony counts (95% credible interval) were 14.4 (7.7-26.7) for vitals machines and 29.2 (16.1-51.1) for workstations on wheels. For the workstations on wheel, colony counts were lower on the mouse, 0.22 (0.16-0.29), tray, 0.29 (0.22, 0.38), and keyboard, 0.43 (0.32-0.55), when compared to the arm, as assessed by incident rate ratios. Although routine disinfection is required, bioburden is still present across portable medical equipment on a variety of surfaces. The difference in bioburden levels among surfaces likely reflects differences in touch patterns for the different portable medical equipment and surfaces on the portable medical equipment. Although the association of portable medical equipment bioburden to healthcare-associated infection transmission was not assessed, this study provides evidence for the potential of portable medical equipment as a vector for healthcare-associated infection transmission despite hospital disinfection requirements.

Evaluasi Efektivitas Kinerja Filter Press Plate and Frame pada Proses Pemanenan Spirulina sp

Spirulina sp can be used as raw material for making masks and medicines. This research wasconducted to determine the effectiveness of the performance of using a Filter Press (plate and frame) in harvesting Spirulina sp. In this study, Spirulina was cultured in 60 L styrofoam containers with different photoperiods (light/T and dark/G), for 12 hours per day (12T-12G). Parameters observed include dry biomass. For 12 hours per day (12T-12G), Press Filters with 2 and 3 plates were used and pressure of procrsess are 1, 1.5, and 3 Psi. In this study, Spirulina sp can grow well with a concentration of 0.6636 gr mL-1. The filter press plate and frame can be used to harvest Spirulina Sp with the optimum conditions for the Spirulina filtration process by pressing two psi and the number of plates 3, where the highest amounts of filtered Spirulina are 39.653 g with a filtering time of 2 x 103 seconds.

Longitudinal Assessment of Contamination Patterns on Workstations on Wheels (WOWs)

Background Representations of contamination on portable medical equipment inform strategies to prevent transmission and healthcare-associated infections (HAIs). While periodic disinfection of equipment is required in most hospitals, the complexity of demands on staff may limit their ability to adequately disinfect multiple surfaces and touch points on a piece of equipment. The purpose of this study was to determine if current disinfection practices were effectively managing bioburden on WOWs on our hospital wards. Methods Samples were collected using press plate for four weeks from 10 WOWs on three medical-surgical units in our hospital. The sampling scheme limited the ability of staff to anticipate sampling and ensured multiple surfaces on each WOW were consistently sampled. Aerobic bacterial colony counts were calculated after 24 hours of incubation. Bayesian multilevel models estimated the mean bioburden and compared bioburden from different locations on WOWs. Results Out of the 452 samples, the estimated mean colony count (95% credible interval) was 29.2 (16.1-51.1). The incident risk-ratio comparing the handle to the other surfaces on the WOWs were 0.43 (0.32-0.55) for the keyboard, 0.29 (0.22-0.38) for the tray, and 0.22 (0.16-0.29) for the mouse. Conclusions The handle used for moving the WOW around, had greater bioburden compared to the keyboard, tray, or the mouse. Difference in the bioburden may reflect number of touches and lack of hand hygiene when moving equipment. The lower bioburden on keyboards and mouses may conversely reflect greater attention to hand hygiene or may be an artifact of sampling (less contact with press plates). The correlation of bioburden to HAI transmission was not studied here so the significance of bioburden alone in the absence of HAI monitoring is uncertain. Representations of contamination on portable medical equipment inform strategies to prevent transmission and healthcare-associated infections (HAIs). While periodic disinfection of equipment is required in most hospitals, the complexity of demands on staff may limit their ability to adequately disinfect multiple surfaces and touch points on a piece of equipment. The purpose of this study was to determine if current disinfection practices were effectively managing bioburden on WOWs on our hospital wards. Samples were collected using press plate for four weeks from 10 WOWs on three medical-surgical units in our hospital. The sampling scheme limited the ability of staff to anticipate sampling and ensured multiple surfaces on each WOW were consistently sampled. Aerobic bacterial colony counts were calculated after 24 hours of incubation. Bayesian multilevel models estimated the mean bioburden and compared bioburden from different locations on WOWs. Out of the 452 samples, the estimated mean colony count (95% credible interval) was 29.2 (16.1-51.1). The incident risk-ratio comparing the handle to the other surfaces on the WOWs were 0.43 (0.32-0.55) for the keyboard, 0.29 (0.22-0.38) for the tray, and 0.22 (0.16-0.29) for the mouse. The handle used for moving the WOW around, had greater bioburden compared to the keyboard, tray, or the mouse. Difference in the bioburden may reflect number of touches and lack of hand hygiene when moving equipment. The lower bioburden on keyboards and mouses may conversely reflect greater attention to hand hygiene or may be an artifact of sampling (less contact with press plates). The correlation of bioburden to HAI transmission was not studied here so the significance of bioburden alone in the absence of HAI monitoring is uncertain.

Influence of Complex Fluid Flow on Temperature Distribution in the Rotor Region of Large Hydrogenerator Under the Rotor Rotation

Ventilation cooling design is one of the key technologies during the design of large hydrogenerator. With the increase of hydrogenerator capacity, the overheating problem of rotor region become more and more serious. In this paper, a 250 MW hydrogenerator is analyzed. The transient electromagnetic field of the hydrogenerator is calculated. The losses (heat sources) of rotor components in the rotor region of the hydrogenerator are determined. Three-dimensional fluid and thermal coupled mathematic model of the hydrogenerator rotor region is established. The rotor rotation of the hydrogenerator is considered. The distribution of complex fluid velocity in the rotor region is calculated using the finite volume method. The influence of fluid velocity in the different directions on the temperature of the rotor excitation winding is studied under the different flow rates in the rotor region. The surface heat-transfer coefficient distribution of the rotor components is determined. The temperature distribution of the rotor excitation winding, rotor pole body, rotor press plate, rotor damping bar, and rotor end ring is obtained. The calculated temperature results match well with test values. These provide an important reference for the rotor structural design and optimization of larger hydrogenerator.

ДОСЛІДЖЕННЯ ФІЗИЧНИХ ПРОЦЕСІВ У ТОРЦЕВІЙ ЗОНІ ТУРБОГЕНЕРАТОРА ПРИ МЕХАНІЧНИХ УШКОДЖЕННЯХ КРІПЛЕННЯ ОСЕРДЯ СТАТОРА

With the help of mathematical simulation of mechanical processes in the stator core fastening system of a powerful turbogenerator end zone obtained appropriateness of basic parameters changes at the break of clamp prisms heads of the stator core. It is determined that the sudden break of one or more clamp prisms leads to longitudinal oscillation of their other working heads and stiff connected with them press plate, accordingly. Although such oscillation is insignificant but propagates along the entire surface of the press plate with a maximum value in the break zone and subsequent decrease with distance from this zone and therefore can be detected with the help of existing vibration sensors by installing them on the press plate. It is possible to use a limited number of sensors due to the propagation of vibration along the entire surface of the plate. But because the vibration changes are insignificant, in this case, there is a complexity of control that requires the use of high-sensitivity sensors and great informative computing equipment. According to the sensors indices, it is possible to determine the number of breaks for clamp prisms heads of the stator core and the number of them working heads, accordingly. Besides, this effect can be used to diagnose the un-compression of the stator core tooth zone. Since one of the important ways to improve the control and diagnostics of turbogenerators is the detection, the presence of such knowledge will allow making the optimal decision for further measures. References 8, figures 8, tables 2.

Controlled curing of thermoset composite components using infrared radiation and mathematical modelling

The production and curing of thermoset fibre composite components are usually carried out using conventional heating techniques at atmospheric pressure with an oven, pressurised forced convection using an autoclave or a conductive system using a heating press or metal plate. Each of these techniques is energy demanding and requires high capital investment. A novel process using only a controlled and required minimal amounts of energy from infrared radiation has been developed. Due to the ease of monitoring the infrared radiation, this newly developed process is more adaptable, controllable and cost-efficient than existing techniques. The novelty of this research is the development of a mathematical model to predetermine the infrared heater parameters required to cure complex shape composite components. Using this technique, thermoset composite components can be manufactured correctly from initial production runs.

Influence of global and local process gas shielding on surface topography in laser micro polishing (LμP) of stainless steel 410

Laser micro polishing (LμP) is a new laser-based material processing method that has a high potential to overcome common disadvantages of traditional polishing techniques. A special challenge in LμP is the processing of large areas since processing in a process gas atmosphere is deemed necessary to avoid undesired oxidation and minimize surface roughness. Therefore, a new process strategy for LμP on stainless steel AISI 410 was investigated in which a gas nozzle was used to create a local process gas shielding and therefore to significantly increase the field of maximal processing. Using a Nd:YAG high power Q-switch laser, we demonstrated that local process gas shielding is feasible for LμP in terms of avoidance of surface defects and achieved micro-roughness. In addition, a wide process window in terms of nozzle distances and gas flow exists for LμP. The resulting surfaces are highly reproducible in terms of surface roughness. Besides Argon, Nitrogen is another process gas that is highly suitable for LμP of AISI 410. The use of Nitrogen might therefore significantly lower future production costs in LμP. Finally, spatially resolved LμP was explicitly demonstrated on a textured press plate.

Nonlinear Analysis of Local Corrugated Steel Shear Wall under Lateral Loading

Steel shear wall is one of the types of resistant shear walls against lateral loads of the structure which is considered due to many reasons such as reducing the weight of the steel in the structure and increased speed of construction etc. In order to prevent out-of-plan buckling of steel plate, stiffeners are applied horizontally, vertically or diagonally. A new method used in the recent years is the use of a corrugated plate in various shapes, such as a sine, a trapezoid, a triangular, etc., in the construction of a steel shear wall. The aim of this research is to replace the local corrugated (press) plate with corrugated steel plates. After investigating the force-displacement diagrams in monotonic and cyclic loading, it was obtained that the local vertical trapezoidal presses had better resistance and ductility compared to the local cylindric presses for replacing corrugated and steel shear wall. The results of this research showed that the resistance of the local shear steel wall has a direct relation with the thickness of the plate and a reverse relation with the out of plan dimension of trapezoidal corrugate. Though, in all the tests of the local corrugated steel sheer walls, there is an approximate range in which beyond that range, the above results are not valid.

Fluence of age factor on main strength and deformative properties of timber

The analysis of literature sources on this topic is carried out. It was found that the influence of age on the main strength and deformation parameters has not been studied. The method of experimental researches of coniferous and deciduous species of solid wood of different age at one-time short-term loading along fibers is resulted. To solve the problems, a series of samples of 1 sort of solid wood in the form of prisms with a cross section of 30x30x120 mm were made. The following species of wood were tested: coniferous species - larch, pine, spruce; deciduous - birch, alder, ash. The age of wood was 20, 40, 60 years. At the time of testing, the moisture was 12%. The humidity of the wood was controlled using a moisture meter MD-814. Experimental studies were performed on a servo-hydraulic test machine STM-100 under a rigid load regime (by increasing the displacements of the press plate of the test machine). Based on the obtained results, complete diagrams of deformation of deciduous (birch, alder, ash) and coniferous (larch, pine, spruce) species of solid wood at different ages (60, 40, 20 years) were constructed. The number of twin samples that were tested was 126 pieces. The main strength and deformation parameters were determined experimentally, in particular the average critical deformations of all studied wood species and the corresponding average maximum stresses. It is established that in the case of a rigid test regime, the deformation diagram of solid wood necessarily has two branches - ascending and descending. That is, the samples work in the so-called supercritical stage of work. It was found that the age of wood directly affects the strength and deformability of solid wood. In particular, with increasing age from 20 to 60 years, the strength and deformability of deciduous and coniferous species of solid wood increases significantly. Based on the test results, conclusions were drawn. Further research on this topic is highlighted.

ЕКСПЕРИМЕНТАЛЬНІ ДОСЛІДЖЕННЯ СУЦІЛЬНОЇ ДЕРЕВИНИ КОНСТРУКЦІЙНИХ РОЗМІРІВ З ВРАХУВАННЯМ ФАКТОРА ВОЛОГОСТІ

2National University of Water and Environmental Engineering, Rivne Materials, elements and structures made of wood can be operated in environments with different humidity. Humidity of wood directly affects its strength and deformable properties. The works of domestic and foreign authors who studied the effect of moisture on the strength and deformability of wood of different species were analyzed in detail. It turned out that there are very few such works. According to these works, it is difficult to detect the effect of moisty on the basic physical and mechanical properties of wood. And they usually concerned the testing of wood under a soft load regime, which does not fully reflect their real stress-strain state. We have developed a method of experimental studies of various deciduous (birch, alder, ash) and coniferous (larch, pine, spruce) compression along the fibers with a single short-term load under a rigid test mode (by increasing the displacement of the press plate) with different moisture (30%, 21% , 12%). The age of all wood samples was 60 years. Section of prisms 30x30x120mm and grades of wood without defects and damages. The total number of tested samples - 126 pcs. After conducting experimental research and processing the results, complete diagrams of deformation of wood σ-u deciduous (birch, alder, ash) and coniferous (larch, pine, spruce) wood species from the beginning of loading and to the point of ultimate deformation, respectively, at a moisty of 30% , 21%, 12%. For the first time, critical deformations of different wood species at the corresponding maximum stress at different moisty were obtained experimentally. It was found that with a decrease in moisty from 30% to 12%, the strength of wood of all species increases. The critical deformations herewith are reduced.

MENENTUKAN VARIABEL YANG PALING BERPENGARUH TERHADAP KINERJA POMPA HIDRAM MENGGUNAKAN METODE ESTIMASI EFEK ALGORITMA YATES

In each study, often many variables are used and interrelated with each other. The increasing number of variables often confuses which variables are the most dominant for changes or desired results.Many methods are used to find the most dominant variable in influencing the research output.Factorial 2 3design with estimated effects of Yates algorithm is a method that can be used to find the most dominant variable in influencing output. This study aims to find the most dominant variable on the output pressure generated by the hydram pump. The results calculated using this method are the result of flow simulations in pumps with CFD [1]. Variables used are valve opening, a height of the water flow, and valve type. The greater the velocity of water flow in the drive pipe, the greater the flow rate of the water in the delivery pipe and the flow rate of the pressure valve. The drag coefficient of the ball valve press model is smaller than the valve press plate model, so it requires a smaller force to open and close the valve. In accordance with the valve on the hydram pump which requires the process of opening and closing the valve must be fast so that it can provide better performance [2]. The simulation results also show that the most optimal step valve press length is at the valve opening-diameter ratio of 0.16. This research is expected to provide input on the design of the hydram pump in the future

Influence of Extension Length of Rotor End Windings on the Three-Dimensional Electromagnetic Field and Temperature Rise in the Large Turbine Generator End Zone With Magnetic Screen

Leakage magnetic field from the rotor end windings affects obviously the electromagnetic losses and temperature of end components in the turbine generator end zone with magnetic screen. As the capacity of turbine generator increases, this effect of rotor end windings has become more prominent. To investigate influence of the extension length of rotor end windings on the electromagnetic and thermal fields in the turbine generator end zone with magnetic screen, three-dimensional transient electromagnetic field model of 1250 MW turbine generator end zone is given. Leakage magnetic field and losses of end components are compared and studied in the end zone under the different extension lengths of rotor end windings. Based on the calculation results of electromagnetic losses (heat sources) and flow network (boundary conditions), three-dimensional fluid-thermal coupling field is calculated in the turbine generator end zone with magnetic screen. Distribution of complex fluid velocity in the end zone is obtained. Influence of the different extension lengths of rotor end windings on the stator-end copper coil, screen plate, finger plate, press plate, magnetic screen, and stator end core is researched in the turbine generator end zone. The accuracy of calculation results is validated by experimental values.

Influence of the modes of shaping of sand-resin shellis on quality of the produced castings

Resin in sand-resin mixes in the course of heating at production of casting shell molds undergoes changes of a state: solid – liquid – solid. For the purpose of increase in durability and decrease in contents of binding (pulverbakelit) in mix when forming a shell, along with thermal influence, the static pressure, the resines changing in compliance with change of aggregate state was used. Basic pressure is 0.25 MPas and moves through a press plate right after filling of mix on heated up to 230 °C model plate. In 10 seconds pressure increases up to 0.35 MPas. And in 10 seconds pressure goes down to 0.2 MPas. It is experimentally defined that the castings received in the shell forms made with use of variable pressure have the minimum and uniform internal tension. Also researches showed that such castings have high purity of a surface (Rz 70–80) and lack of internal defects.

Influence of Magnetic Permeability of the Press Plate on the Loss and Temperature of the End Part in the End Region of a Turbogenerator

Press plates are widely used in the end region of turbogenerators. However, due to the effect of magnetic field leakage from the end region, the eddy current losses of the copper screen and press plate will result in the copper screen and press plate having a high temperature under the rated load condition. In this paper, the influence of the magnetic permeability of the press plate on losses and temperature of the end region is researched in turbogenerators. Three-dimensional (3-D) fluid and thermal mathematic and physical models of the turbogenerator end region are established. Under different magnetic permeability values of the press plate, a 3-D transient electromagnetic field in the turbogenerator end region is calculated, and the obtained losses of the end parts are treated as heat sources. Fluid network equations are calculated, and the obtained fluid velocity and pressure values are applied to the end region as boundary conditions. After solving the fluid and thermal equations, fluid velocity around the surface of the end parts is obtained under the rated load condition. The temperature distribution of the end parts is determined for different magnetic permeability values of the press plate. The calculated temperature results agree well with the test data.

The influence of pigment proportions and calendering of coated paperboards on dot gain

Dot gain is called Tone Value Increase (TVI). Low dot gain and rounder dot shape are important properties to obtain a good print. Dot gain is a measure of how much extra weight a given percent dot or tone has gained on the final printed substrate by comparison to the actual dot area on a press plate. Dot gain value depends on many factors. The interactions of paper, ink and press conditions are important determinates for a good print. In addition, the pigment coating process and calendering conditions have a significant effect on the printability of paperboards. Pigment coating formulations including mineral pigments, binders and additives improve the gloss, brightness, opacity and smoothness of the paperboards. As a result, print quality of paperboards increase. A uniform paperboard surface is needed to obtain a high quality surface smoothness after the coating process. High surface smoothness improves the uniformity of the dot shape and size. Pigment coating formulation parameters; pigment selection, binder selection and binder level influence print quality. The aims of this study - pigment selection and ratio - are to determine the effect on dot gain in lithography printing. To this aim, base paperboards were coated using five pigment coating formulations which included different combinations of kaolin, calcium carbonate and titanium dioxide pigment with a styrene\n-butyl acrylate copolymer binder using a bar application. After coating, the samples were air-dried overnight under TAPPI conditions. Then, half of the coated-paperboards were calendered. Tone scales from 1 to 100 % were offset printed using black ink on the uncalendered and calenderedcoated paperboards. Then, from the printed tone scale, the tone area values were measured with the Gretagmacbeth Spectrolino spectrophotometer. These values showed that pigment coating improved the surface optical and physical properties of paperboards. After calendering, the roughness values of coated paperboards decreased. In addition, the obtained dot and line sharpness on calendered-coated paperboards were better than on uncalenderedcoated paperboards. However, the dot gain values of calendered-coated paperboards had fewer dot gains than uncalendered-coated paperboards. It was established that the variation of pigment proportions in the coating formulations had no significant effect on dot gain.

Development of a Self-balanced Rock True Triaxial Compression Instrument

Based on the analysis of the structure and the performance of similar instruments at home and abroad, a Self-balanced Rock True Triaxial Compression instrument (SRT) was developed. For SRT, complex stress realization, based on three-dimensional stress alone control and change; and the self-balanced structure is adopted on the basis of frame design, which makes the instrument simple and compact; design of lateral composite press plate with embedded rolling roller, the influence of test results on the effect of friction on the side end surface of the specimen under lateral stress constraint can be eliminate effectiveness; The design scheme of transverse double sliding rod is adopted, its validity can be designed by horizontal alignment, and the problem of eccentric compression of specimen can be partly alleviated in horizontal direction. By changing the alkali of the mothed triaxial chamber, both true triaxial and conventional triaxial compression can be tested. Test results of true triaxial and conventional compression of rocks with different lithology were carried out by SRT. The results, such as the deformation and failure characteristics of rock strength in complex stress conditions, have been obtained by SRT, which indicates that the design of SRT is feasible and feasible. The development of this instrument can promote the further development of Chinese rock triaxial testing machine.

Numerical analysis of end part temperature in the turbogenerator end region with magnetic shield structure under the different operation conditions

Due to the serious overheating problem of end parts in the large turbogenerator end region, accurate calculation of end-part temperature has become a key design factor. In this paper, 3-D fluid and thermal coupling model in the end region of 1250 MW turbogenerator are given. The loss values gained from 3-D transient electromagnetic field calculation are applied to the solving end region as heat sources. Pressure value of fan outlet and fluid velocities of end region inlets from flow network calculation are applied to the solving end region as boundary conditions in the 3-D fluid and thermal coupling analysis model. The fluid flow and temperature distribution of end parts in the end region of large turbogenerator with magnetic shield structure are studied under the different operation conditions. The distribution of fluid velocity in the ventilation duct of stator end core is obtained. The temperature distribution laws of stator-end copper coils, screen plate, finger plate, press plate, and magnetic shield are researched under the different operation conditions. The location of the highest temperature point in the turbogenerator end region with magnetic shield structure is determined. The accuracy of numerical calculation is validated by experimental measured values.

Комбінований механізм приводу натискної плити плоского штанцювального преса (експериментальна оцінка навантажень)

Комбінований механізм приводу натискної плити плоского штанцювального преса (експериментальна оцінка навантажень)

Експериментальна оцінка впливу швидкісного режиму на силові навантаження комбінованого механізму привода натискної плити при штанцюванні картону

Експериментальна оцінка впливу швидкісного режиму на силові навантаження комбінованого механізму привода натискної плити при штанцюванні картону