Practical Control Method Research Articles

Potential of RNAi applications to control viral diseases of farmed shrimp.

Viral pathogens pose a primary threat to global shrimp aquaculture. Despite the urgent industry need for them, practical anti-viral control methods are unavailable due, in part, to lack of an adaptive immune response in crustaceans that renders conventional vaccination methods ineffective. One currently studied method of high interest for protecting shrimp against viral infection relies on the post-transcriptional gene silencing mechanism called RNA interference (RNAi) that is induced by gene-specific constructs of double stranded RNA (dsRNA). Although this approach was first described for successful protection of shrimp against white spot disease (WSD) by injecting dsRNA specific to genes of white spot syndrome virus (WSSV) into shrimp in the laboratory in 2005 no practical method for use of dsRNA in shrimp farms has been developed to date. The apparent bottleneck for farm-scale applications of RNAi-mediated viral control in shrimp aquaculture is the lack of simple and cost-effective delivery methods. This review summarizes recent studies on use and delivery of dsRNA to shrimp via injection and oral routes in hatcheries and on farms and it discusses the research directions that might lead to development of practical methods for applications with farmed shrimp. Oral delivery methods tested so far include use of dsRNA-expressing bacteria as a component of dry feed pellets or use of living brine shrimp (Artemia) pre-fed with dsRNA before they are fed to shrimp. Also tested have been dsRNA enclosed in nanocontainers including chitosan, liposomes and viral-like particles (VLP) before direct injection or use as components of feed pellets for hatchery or pond-reared shrimp.

Methods of unbalanced voltage control in nonsolidly grounded systems based on current injection

Summary In nonsolidly grounded systems, 3-phase voltage imbalances endanger the system safety. On the basis of the principle of unbalanced voltage control through injecting current, the variation of unbalanced voltage along with the injected current's amplitude and phase was studied. Three practical closed-loop unbalanced voltage control methods are given, such as the 2-point method, the tracking method, and the synthetic method. The synthetic method combines the advantages of the 2-point method and the tracking method and is fast to control with a high precision. Compared with traditional methods, the proposed methods advance in means such as higher precision, more flexible control, less investments, and better adaptation in systems with dynamic changes. The methods are verified in designed simulation.

Vector Control in Developing Countries: Challenges and Solutions.

Undoubtedly, reducing vector populations or their interactions with hosts below a critical level is a practical and proven method of disease control. Introduction of insecticide-treated bed nets has significantly reduced malaria in some parts of the world. However, for many reasons, implementation of such strategies is challenging and the protection offered by particular products limited: bed nets are only effective during sleep. Other methods have been launched, but low customer appeal, high cost, low specificity, and lack of sustainability and effectiveness are often reasons for failure. The proposed solution to these problems should also consider safety and environmental impact and be forward-thinking for continued functioning in a rapidly changing local environment. To this end, a chemical system has been identified that could be used to make an autonomous trap with chemo-attractant system.

Shoreline Drizzle Applications for Control of Incipient Patches of Yellowflag Iris (Iris pseudacorus)

Yellowflag iris, native to Europe, is a rhizomatous, emergent, invasive plant found in pond margins, ditches, and other wetland sites in much of the United States. In water depths up to approximately 50 cm, it forms dense stands, which displace native sedges and rushes, reducing waterfowl habitat and water flow. The rhizomes can reach 6 m in lateral spread, making it very difficult to control by mechanical methods. In addition, conventional boom-sprayer applications are often impractical in most aquatic systems. Drizzle application is a technique for directed treatment of hard-to-reach invasive plants. It uses low volumes (26 to 104 L ha—1) of concentrated herbicide solution, applied using a spray gun emitting a thin stream of solution with an effective range of 6 m. In this study, conducted along the margins of two ponds at the University of California, Davis, we compared drizzle applications of glyphosate, imazapyr, and triclopyr to applications using a conventional boom sprayer. Although both glyphosate and imazapyr provided excellent control (> 96 %) of yellowflag iris with either treatment technique, only the drizzle treatments of imazapyr at 2.26 and 4.52% ae (10 and 20% product) at spray volumes of 52 and 26 L ha—1, respectively, were below the maximum labeled rate and still gave > 98 % control. Furthermore, a cost analysis indicated that the most economical application for effective control of yellowflag iris was a drizzle application of imazapyr at 4.52 % ae (20 % product) at 26 L ha—1. This study demonstrates that drizzle application with imazapyr can be a practical application method for yellowflag iris control in aquatic systems in which broadcast treatments with conventional boom sprayers may be difficult.

Comparison of Immunogenic Effect of Three Oil Adjuvant Vaccines against Haemorrhagic Septicaemia in Cattle and Buffalo

Haemorrhagic Septicaemia is one of the most common, fatal and acute bacterial diseases of livestock which causes mortality above 70% and is caused by Pasteurella multocida. The only satisfactory and practical method of control and prevention is timely vaccination of all the healthy and in contact animals. Different types of vaccines are being used for the immunity against this disease. In this project three oil based vaccines were produced. Two single emulsion vaccines were prepared by utilizing Montanide ISA-50 and liquid paraffin with lanolin where as one double emulsion with the help of Montanide ISA-206 was prepared. In house quality control testing and safety testing was performed on swiss albino mice. For immune titre IHA was performed by collecting serum from each and every animal including control animals. The comparison of IHA was done via statistical analysis by using GMT, Single emulsion vaccine prepared from liquid paraffin with lanolin gave maximum immune titre out of all the three vaccines in large animals and in young calves ISA 206 gave a significant titre.

A Practical Multivariable Control Approach Based on Inverted Decoupling and Decentralized Active Disturbance Rejection Control

Conventional multivariable controls may face challenges in industrial implementation due to their computation intensity, controller complexity, and/or poor robustness. To this end, this paper developed a practical multivariable control method, consisting of inverted decoupling and decentralized active disturbance rejection controller (ADRC). Strong robustness is achieved with negligible computation and simple forms of the decoupler and controller. Moreover, the disturbance rejection is markedly accelerated. On the basis of the two-input–two-output (TITO) system description, first discussed are the practical advantages of inverted decoupling that can be easily extended to high dimensional systems. Particularly, a compensation method is proposed to make the inverted decoupling applicable for the processes with right-half plane zeros. Then, the ADRC is bridged to the PI controller and the internal stability and robustness are analyzed. The feasibility of implementing ADRC in industrial distributed control sy...

Operation and control of an insulated gate bipolar transistor‐based current controlling device for power flow applications in multi‐terminal high‐voltage direct current grids

One of the main problems that need to be solved to allow the realisation of multi-terminal high-voltage direct current (HVDC) transmission systems is the absence of a practical power flow control method. Industry leaders and researchers have proposed a few methods of power flow control based on either the control of converter station or the connection of new power electronic equipment to the grid. This study presents the operation and control of a three-port insulated gate bipolar transistor-based current flow control (CFC) device suitable for multi-terminal HVDC systems. Key features and functionalities of the proposed controller including the balancing of cable currents, limiting the magnitude of cable current and current nulling are demonstrated. The three-port CFC was simulated using power system computer aided design (PSCAD)/electromagnetic transient and direct current (EMTDC), network simulation software to evaluate its steady state and dynamic performance. Furthermore, low-power prototypes are implemented for a two and three-ports CFC to experimentally validate their different functionalities. Simulation and experimental studies explore the fast dynamic response and the results show that the CFC studied may have a significant role to play in the control of power flows in multi-terminal high-voltage DC systems.

Adaptive Job-Shop Control Using Resource Accounts

The control of todays production systems has become more complex due to an increasing number of products, product variants, randomly incoming orders and non-standardized production processes. Specifically job-shop production is indispensable for single- and small-series- productions with low repetition rates. However, their productivity yields disadvantages compared with flow production. Self-regulating methods of production control like the Decentralized WIP-oriented manufacturing control (DEWIP) by Loedding [2] offer potential for compensating this disadvantages. Though, with an increasing variety in order sequence, it is getting increasingly difficult to estimate the effects of control activities on other orders in the following production flow. Thus, job-shop production with widely ramified material flows is usually organized manually. Decisions to overcome disturbances and deviations from the production plan are made locally by foremen or workers. Those decisions base on their experience and know-how, however with the same deficit regarding the estimation of the subsequent production process concerning disruptions. This paper presents a work in process (WIP) regulating method of production control which has been designed specifically for the requirements of typical job-shop productions. It combines the advantages of load balancing over the complete production, as proposed by Bechtes Load-Oriented Order Release [3] with the adaptivity of decentralized production control, like in DEWIP. By balancing current and prospective utilization via so-called resource accounts, bottlenecks are identified before they appear on the shop floor. Thus, alternative material flows bypassing the bottleneck processes can be activated adaptively as well as measures to extend the capacity can be undertaken. This paper presents the concept and its elaboration to a practical method for job-shop control. In addition, it was implemented in a simulation model in order to demonstrate the suitability and the effectiveness for production control in manual job-shop production systems.

Cyclic testing of chevron braced steel frames with IPE shear panels

Despite considerable life casualty and financial loss resulting from past earthquakes, many existing steel buildings are still seismically vulnerable as they have no lateral resistance or at least need some sort of retrofitting. Passive control methods with decreasing seismic demand and increasing ductility reduce rate of vulnerability of structures against earthquakes. One of the most effective and practical passive control methods is to use a shear panel system working as a ductile fuse in the structure. The shear Panel System, SPS, is located vertically between apex of two chevron braces and the flange of the floor beam. Seismic energy is highly dissipated through shear yielding of shear panel web while other elements of the structure remain almost elastic. In this paper, lateral behavior and related benefits of this system with narrow-flange link beams is experimentally investigated in chevron braced simple steel frames. For this purpose, five specimens with IPE (narrow-flange I section) shear panels were examined. All of the specimens showed high ductility and dissipated almost all input energy imposed to the structure. For example, maximum SPS shear distortion of 0.128-0.156 rad, overall ductility of 5.3-7.2, response modification factor of 7.1-11.2, and finally maximum equivalent viscous damping ratio of 35.5-40.2% in the last loading cycle corresponding to an average damping ratio of 26.7-30.6% were obtained. It was also shown that the beam, columns and braces remained elastic as expected. Considering this fact, by just changing the probably damaged shear panel pieces after earthquake, the structure can still be continuously used as another benefit of this proposed retrofitting system without the need to change the floor beam.

Quantification of applied dose in irradiated citrus fruits by DNA Comet Assay together with image analysis

The experiments were conducted for quantification of applied dose for quarantine control in irradiated citrus fruits. Citrus fruits exposed to doses of 0.1 to 1.5kGy and analyzed by DNA Comet Assay. Observed comets were evaluated by image analysis. The tail length, tail moment and tail DNA% of comets were used for the interpretation of comets. Irradiated citrus fruits showed the separated tails from the head of the comet by increasing applied doses from 0.1 to 1.5kGy. The mean tail length and mean tail moment% levels of irradiated citrus fruits at all doses are significantly different (p<0.01) from control even for the lowest dose at 0.1kGy. Thus, DNA Comet Assay may be a practical quarantine control method for irradiated citrus fruits since it has been possible to estimate the applied low doses as small as 0.1kGy when it is combined with image analysis.

Contamination of dental goggles and effectiveness of 3 disinfectants in a stomatology hospital

We investigated the contamination levels of dental goggles to assess the infection risk in a stomatology hospital and compared the effectiveness of 3 disinfectants, including Swashes (Swashes Enterprise, Co. Ltd., Shenzhen, China), medical ethanol (75%), and chlorine-containing disinfectant (500mg/L). The results showed that 87.41% of goggles had bacterial contamination. In total, 54% of cultures included gram-positive cocci, making them the major microbial group contaminating the goggles. All 3 disinfectants showed excellent performance in disinfection, and there were no significant differences among the eligibility rates of the 3 disinfectants (97.2% vs 100.0% vs 100.0%, respectively). The study highlights the fact that dental goggles are potential reservoirs of nosocomial pathogens. Disinfection of goggles could be an effective and practical infection control method for dental practice.

Incubation Chamber Temperature Controller Design and Simulation

The traditional incubation chamber temperature PID control system has poor stability, control precision results are poor, not adjust the PID parameters and other issues, this paper presents a way to use Darling algorithm design incubation chamber temperature controller scheme, and introduced this system controller algorithm design steps, simulation results, and conducting field experiments. Simulation results show that the practical result table control method overshoot, settling time shortened, and can effectively improve system response speed and control precision.

Generalized proportional integral observer based control of an omnidirectional mobile robot

This paper presents an observer based trajectory tracking control system design for an omnidirectional mobile robot with MY wheel-II. MY wheel-II is a switch wheel mechanism. Switch wheeled omnidirectional mobile robots are complicated autonomous switched nonlinear systems. In this paper, the complicated switching dynamics, unmodeled dynamics and input–output cross-couplings are considered as an unknown time-varying perturbation input vector, which is online estimated by means of a generalized proportional integral observer. The original switched nonlinear multi-input multi-output system is then reduced to three decoupled double integrators in an approximate manner. Traditional proportional derivative controllers are then applied to the decoupled double integrators. In addition, only part of the robot model information is used in the control system design. Simulation and experimental tests illustrate the effectiveness of this practical control method.

A novel slack bus-free load flow method for dc microgrids and distribution systems with dc-bus signaling control methods

SUMMARY A significant section of the future electrical power systems, that is, smart grids, will be dc microgrids and distribution systems. Obviously, the voltage control is one of the important issues of these dc power systems. DC-bus signaling (DBS) control methods, as distributed, autonomous, simple, highly reliable, inexpensive, modular and practical control methods, are one of the most important categories of the voltage control methods in dc microgrids and distribution systems. In the dc power systems with DBS control methods, the determination of the generated power shares of the distributed power sources, as vital entries for the conventional load flow methods, before the execution of a load flow method, is not possible. Also, in these dc power systems, none of the power sources can be considered as a constant voltage source, that is, the slack source. Consequently, the conventional load flow methods are not applicable to dc microgrids and distribution systems with DBS control methods. In this paper, a novel, practical, robust, fast, precise load flow method is presented to overcome the mentioned serious complexities in the dc power systems. The proposed load flow method necessitates the least input data. It determines the generated power shares of all the sources during its execution. Besides, the load flow method necessitates no constant voltage source or slack source. Furthermore, the proposed load flow method benefits from low computational time and the storage requirements and the removal of the ill-conditioned problem. The algorithm validation and the numerical results derived in this paper confirm the accuracy and the remarkable performance of the load flow method. Copyright © 2015 John Wiley & Sons, Ltd.

Strain-optic active control for quantum integrated photonics.

We present a practical method for active phase control on a photonic chip that has immediate applications in quantum photonics. Our approach uses strain-optic modification of the refractive index of individual waveguides, effected by a millimeter-scale mechanical actuator. The resulting phase change of propagating optical fields is rapid and polarization-dependent, enabling quantum applications that require active control and polarization encoding. We demonstrate strain-optic control of non-classical states of light in silica, showing the generation of 2-photon polarisation N00N states by manipulating Hong-Ou-Mandel interference. We also demonstrate switching times of a few microseconds, which are sufficient for silica-based feed-forward control of photonic quantum states.

Sperm membrane proteome in wild Japanese macaque (Macaca fuscata) and Sika deer (Cervus nippon)

Whereas recent advances in proteome-related techniques have accumulated a lot of information about sperm proteins in model animals, the information in non-model wildlife species is absolutely deficient, although this knowledge would be valuable to regulate wildlife overabundance. To characterize the repertoires of sperm membrane proteins in Japanese overpopulated wildlife, our study focuses on the following two species: Macaca fuscata and Cervus nippon. We enriched sperm membrane proteins by the phase partitioning with Triton X-114, and then separated them by two-dimensional electrophoresis, and, finally, they were comprehensively identified by peptide mass fingerprinting. Sperm membrane proteins were successfully enriched. They included some proteins with unknown function and fertility-related proteins that work in sperm development, motility, capacitation, transport, protection, acrosome reaction, and fertilization. Additionally, beta-defensin 126 and epithelial chloride channel were strongly detected in M. fuscata but not in C. nippon, whereas lactadherin and NADH-cytochrome b5 reductase 1 were strongly detected in C. nippon alone. This study is an initiative case showing that the sperm of wildlife conserve major fertility-related proteins, but express some proteins in a species-specific manner. In the development of a practical method for fertility control, this aspect may be taken into consideration.

Decomposition of a tribological system by chaos theory on rough surfaces

The purpose of this paper is to analyze the turning machinability of a martensitic steel, according to the cutting speed, and through signal analyses of the morphology of the machined surface. We initially carried out the classification of a large number of parameters of roughness, on the basis of their relevance with regard to cutting speed. The originality of the proposed method lies in the combination of the classical technique of analysis of variance with the statistical technique of resampling of data, called Bootstrap. Another characteristic of the study consists in the addition to the traditional categories of roughness parameters (Amplitude, Frequency, Morphological and Hybrid parameters) to analyze multiscale aspect of surface topography through fractal analysis. According to the analysis carried out, the fractal dimension and the slope of the signal (dz/dx) of the topographical signal of the studied surface appear much more relevant than all the other Euclidian parameters. The fractal dimension and the slope of profile allow us to estimate a critical transition speed between the cutting states by generalized strain hardening and those by localized strain hardening. This parameter is also more relevant than the others, because it allows a good analysis of the influence of cutting speed, within each of the two machining modes. The obtained result is relevant because it provides a practical and inexpensive method for the quality control of the machined surface, to manufacturers and engineering companies, without removing some mechanical part, but only through a direct analysis of the slopes of the profile, with, in particular, the help of a portable instrument. We establish later that the transition between disorder and order of the aspect of the observed profiles is essentially due to an instability, which we analyze by the chaos theory. For that purpose, we propose an original construction of an attractor that presents a fixed point for low cutting speeds. This attractor characterizes, beyond the critical cutting speed, an instability described by a phenomenon of successions of states on the attractor between work hardening by localized shear plastic deformation and softening due to the rise in temperature.

Cultural and molecular detection of zoonotic tuberculosis and its public health impacts in selected districts of Tigray region, Ethiopia

Bovine tuberculosis (BTB) is a chronic infectious disease of animals characterized by the formation of granulomas in tissues and its detection is carried out most commonly on the basis of tuberculin skin testing, abattoir meat inspection and rarely on bacteriological techniques. A study was conducted to assess the epidemiology and zoonotic implication of bovine tuberculosis in three selected districts of Tigray region between September 2012 and June 2013 using Comparative Intradermal Tuberculin (CIDT) test, abattoir surveillance, bacteriology and molecular typing. Besides, livestock owners were interviewed for the evaluation of the zoonotic potential of BTB. On the basis of the CIDT test, animal and herd prevalence were 2.7% (14/524) and 9.3% (13/140), respectively, while in abattoir-based study the prevalence was 22% (117/531). Male animals were more likely (OR= 1.7; P=0.012; 95% CI: 1.12- 2.55) to exhibit tuberculous lesions as compared to female animals. The proportion of culture positivity was 32% (40/125) in tissue samples. Only nine isolates were typed and out of which seven isolates were positive for the genus Mycobacterium of which two were identified as M. tuberculosis. The two M. tuberculosis species had the same spoligotype pattern. Awareness of cattle owners about BTB was poor and detection of BTB both in live and slaughtered animals. The isolation of M. tuberculosis from animal tissues indicates the existence of transmission of this agent from humans to animals. Therefore, there should be practical and sound control methods such as strict meat inspection, boiling of milk and cooking of meat, and public education to raise the awareness on the transmission of the disease.Keywords: Abattoir , Ethiopia, Mycobacterium, Tuberculosis, Zoonosis

Effects of temperature variations on safety of reinforced concrete structures during construction

Since 1960s, many research works on the reinforced concrete structure have been published and some concise and practical calculation methods for safety control during construction have been achieved. The reinforced concrete structure during construction is a time-dependent structure which consists of a partly completed structure and a formwork-shore system. Experience shows that the most critical condition of the time-dependent structure may happen when the formwork-shore system is partly removed or reset and accidents may occur. In the present paper, effect of ambient temperature variation between day and night is considered, new structural models for reinforced concrete frames, slab-column systems and shear wall structures are proposed, and a new software named Safety Analysis During Construction Considering Temperature (SACT) is also introduced. Compared with on-site measurements, the software SACT is validated for application on construction site.

Control of Stress in Aeroengine Turbine Disk Using Radially Rotating Heat Pipe

Maximal circumferential stress in a rotating disk always appears in the disk hub. The value may be bigger while employing a thermal effect in the aeroengine turbine disk. Although a V-shaped temperature distribution has been proved to be an effective way to reduce the maximal circumferential stress, the existing methods to achieve the distribution may be far from practice. In this paper, a more practical stress control method was proposed by employing a radially rotating heat pipe to achieve an analogous V-shaped temperature distribution, and the numerical investigation was carried out. An analogous V-shaped temperature distribution was achieved. The results showed that, compared with the disk without heat pipes, the maximal circumferential stress in the hub of the proposed disk could be reduced by more than 100 MPa under 10,000 rpm. Additionally, the disk weight and the maximal rim temperature also declined.