Control Information Research Articles

Control system synthesis of formation of carbon products

The object of research is the process of formation of carbon products. The production of carbon products is characterized by considerable resource and energy intensity, therefore the actual task is to increase the efficiency of this production by introducing the optimum operating modes of its component technological processes. One of the main technological processes in the production of carbon products is the process of their formation by squeezing of the electrode mass through a mouthpiece of the corresponding shape in a hydraulic press. All inherited properties that determine the quality of finished products are laid at the stage of pressing the electrode blanks The analysis of the existing control systems for the process of formation of carbon products shows that the formation process is a typical cyclic process. For such processes, the control task is, as a rule, to implement such controls that would ensure that one or more output variables are tracked by a predetermined path of motion, which is repeated from cycle to cycle. A new control system is proposed that provides for iterative learning control in formation of the electrode mass by squeezing through a mouthpiece of the corresponding shape in a hydraulic press. The corresponding ILC algorithm is proposed. Thanks to this solution, a high quality control is provided in the absence of initial uncertainties and external disturbances.

Symbiotic Control in Mechanical Bond Formation.

Since the advent of mechanically interlocked molecules (MIMs), many approaches to templating their formation using various different noncovalent bonding interactions have been introduced and explored. In particular, employing radical-pairing interactions between BIPY(.+) units, the radical cationic state of 4,4'-bipyridinium (BIPY(2+) ) units, in syntheses is not only a convenient but also an attractive source of templation because of the unique properties residing in the resulting catenanes and rotaxanes. Herein, we report a copper-mediated procedure that enables the generation, in the MIM-precursors, of BIPY(.+) radical cations, while the metal itself, which is oxidized to Cu(I) , catalyzes the azide-alkyne cycloaddition reactions that result in the efficient syntheses of two catenanes and one rotaxane, assisted by radical-pairing interactions between the BIPY(.+) radical cations. This procedure not only provides a fillip for making and investigating the properties of Coulombically challenged catenanes and rotaxanes, but it also opens up the possibility of synthesizing artificial molecular machines which operate away from equilibrium.

Symbiotic Control in Mechanical Bond Formation

AbstractSince the advent of mechanically interlocked molecules (MIMs), many approaches to templating their formation using various different noncovalent bonding interactions have been introduced and explored. In particular, employing radical‐pairing interactions between BIPY.+ units, the radical cationic state of 4,4′‐bipyridinium (BIPY2+) units, in syntheses is not only a convenient but also an attractive source of templation because of the unique properties residing in the resulting catenanes and rotaxanes. Herein, we report a copper‐mediated procedure that enables the generation, in the MIM‐precursors, of BIPY.+ radical cations, while the metal itself, which is oxidized to CuI, catalyzes the azide–alkyne cycloaddition reactions that result in the efficient syntheses of two catenanes and one rotaxane, assisted by radical‐pairing interactions between the BIPY.+ radical cations. This procedure not only provides a fillip for making and investigating the properties of Coulombically challenged catenanes and rotaxanes, but it also opens up the possibility of synthesizing artificial molecular machines which operate away from equilibrium.

Quality of agricultural machinery and control of its manufacture and repair

The article considers the factors influencing on the quality of manufacture and repair of agricultural machinery from the perspective of application of one of the newest methods of the quality analysis known as Principle of 5 M - men, methods, materials, machines, measures. It is defined that in all five indices the domestic agricultural machinery considerably lags behind the foreign one. The main reasons are the use of cheap raw materials, the lack of modern processing equipment with high precision, the lack of highly skilled and highly paid workers, the designing of machines by means of archaic methods, the small degree of information support on modern technologies and specifics of branch machinery, especially internationally. The role of control in formation of quality of manufacture and repair of agricultural machinery is highlighted. The purchasing manager of a large repair enterprise has to provide in the contract for delivery of incoming production the conditions on the presence of a defined limit of defects with selective check of incoming consignment. For a small enterprise, there is the simple recommendation to take a technical documentation and instruments of control along when going on a warehouse for spares, and to buy only good products of manufacturer or well-established similar products. The main objectives of metrological service in repair enterprises are defined. Modern metrological provision during machine repair is the system ensuring the quality of control that includes: the strict ensuring unity of measurements; the choice of critical control points, which are subject to rigid control; the feasibility study of choice of measuring instruments by criteria of minimization of costs and losses for controlled products; the regular actions on adjustment of measuring instruments, the tests and control during maintenance and repair of agricultural machinery.

Adaptive Fuzzy Sliding Mode Controller for Attitude Coordinated Control in Spacecraft Formation

AbstractThe attitude coordinated control problem of a spacecraft formation in leader-follower approach is considered in this paper. An adaptive fuzzy sliding mode control scheme is designed to achieve tracking and synchronization in spacecraft formation in the presence of model uncertainties and external disturbances. The proposed control law consists of two parts: equivalent control and switching control. In order to attenuate high-frequency chattering caused by the switching control, the adaptive fuzzy control is utilized to approximate the sign function of the switching control. Moreover, fuzzy rules are employed to smooth the switching control based on the sliding surface. Lyapunov theory is applied to proof the stability of the closed-loop system. Finally, simulation results and comparative analysis are carried out to demonstrate the effectiveness of the proposed method.

Adaptive Fuzzy Sliding Mode Controller for Attitude Coordinated Control in Spacecraft Formation

Adaptive Fuzzy Sliding Mode Controller for Attitude Coordinated Control in Spacecraft Formation

Formation of iron‐rich shelled structures by microbial communities

AbstractIn this paper, we describe the discovery and characterization of shelled structures that occur inside galleries of Pyrenees mines. The structures are formed by the mineralization of iron and zinc oxides, dominantly franklinite (ZnFe2O4) and poorly ordered goethite (α‐FeO(OH)). Subsurface oxidation and hydration of polymetallic sulfide orebodies produce solutions rich in dissolved metal cations including Fe2+/3+ and Zn2+. The microbially precipitated shell‐like structure grows by lateral or vertical stacking of thin laminae of iron oxide particles which are accreted mostly by fungal filaments. The resulting structures are composed of randomly oriented aggregates of needle‐like, uniform‐sized crystals, suggesting some biological control in the structure formation. Such structures are formed by the integration of two separated shells, following a complex process driven likely by different strategies of fungal microorganisms that produced the complex macrostructure.

Fines Migration Control in Sandstone Formation by Improving Silica Surface Zeta Potential Using a Nanoparticle Coating Process

Fines migration is the major reason for productivity decline known as formation damage in oil reservoirs. Nanofluids are good candidates for being injected into nearby wellbore regions because of their very small sizes for remediation purposes. In this article, a novel experimental procedure is utilized to study the use of different types and concentrations of nanoparticles to reduce fines migration in synthetic porous materials. Three types of nanoparticles, MgO, SiO2, and Al2O3, are used here as coating agents of the porous media grains to investigate the reduction of fines movement. The results indicate that the use of 0.97 wt% of MgO nanoparticles injected into the medium improves adsorption of fines by 20% more than the reference state. The obtained results were confirmed with the calculation of dimensionless total energy of interaction.

The Application and Rheological Behavior of Igebu Garri (Cassava Derivative) as a Fluid Loss Inhibitor in WBM Formation

The rheologyical understanding of the drilling mud is imperative to recognize mud performance to efficiency eradicate, suspend cuttings and stabilize wellbore. Rheology of the drilling mud is commonly conserved at requisite rheological standards during the application of additives or dilution, contingent on the operation requirements. This research presents a study on igebu garri (white garri) a local Nigerian cassava derivative and its potential as an alternative to commercial starches, potato and corn, for the purpose of fluid loss and viscosity control in WBM formation. The approximate analysis displayed igebu garri with maximum quantity of protein (5.2%) and fat (14%) among potato (0.8% and 0.68%) and corn (0.66% and 8%)- starch, accordingly. According to the rheological determination, Igebu garri-WBM displayed the capability to form a WBM with superior viscosity and minimum fluid loss, compatible with potato and corn starch, when subjected to the temperature of 250 F in light (1ml), average (2ml) and heavy (1.4ml) mud weights, whereas light weighted potato and corn-WBMs had failed the requirements with fluid loss volume of 3ml and 10ml, respectively. As results illustrate the starches utterly have degraded when subjected to temperature of 300 F leading to high fluid loss, applied to all mud samples devoid of heavy weight potato-WBM (1.6ml). Igebu garri (WG) proved the possibility to be used as polymeric additive for saline drilling fluid formations, in meticulously as fluid loss control additive. This efficiently diminishes the filtrate volume of the saturated salt mud up to 2ml, calculated according to the NISOC specifications.

Adaptability Evaluation of Conformance Control Agents in Low Permeability Reservoirs with Fractures

Several conformance control agents, including preformed particle gel, emulsion microspheres, continuous chromium gel and underground starch graft copolymer gel were evaluated. The properties such as gelation time and gel strength of gel, and expansion of particles and microspheres were tested at high temperature. Also, the injection pressure, plugging strength and resistance factor were measured using the artificial low permeability cores with fractures. It was shown that, for particle type conformance control agents, the particle size should be adaptable with the fracture width. Also, for continuous chromium gel, the added polymer concentration higher, the viscosity is higher, with higher plugging strength. The plugging and strength should be coordinated. The starch graft copolymer gel is easy to be injected into formation and has good plugging property. The results show that underground starch graft gel is more suitable for conformance control in low permeability formation with fractures.

An Ancient Relative of Cyclooxygenase in Cyanobacteria Is a Linoleate 10S-Dioxygenase That Works in Tandem with a Catalase-related Protein with Specific 10S-Hydroperoxide Lyase Activity

In the course of exploring the scope of catalase-related hemoprotein reactivity toward fatty acid hydroperoxides, we detected a novel candidate in the cyanobacterium Nostoc punctiforme PCC 73102. The immediate neighboring upstream gene, annotated as "cyclooxygenase-2," appeared to be a potential fatty acid heme dioxygenase. We cloned both genes and expressed the cDNAs in Escherichia coli, confirming their hemoprotein character. Oxygen electrode recordings demonstrated a rapid (>100 turnovers/s) reaction of the heme dioxygenase with oleic and linoleic acids. HPLC, including chiral column analysis, UV, and GC-MS of the oxygenated products, identified a novel 10S-dioxygenase activity. The catalase-related hemoprotein reacted rapidly and specifically with linoleate 10S-hydroperoxide (>2,500 turnovers/s) with a hydroperoxide lyase activity specific for the 10S-hydroperoxy enantiomer. The products were identified by NMR as (8E)10-oxo-decenoic acid and the C8 fragments, 1-octen-3-ol and 2Z-octen-1-ol, in ∼3:1 ratio. Chiral HPLC analysis established strict enzymatic control in formation of the 3R alcohol configuration (99% enantiomeric excess) and contrasted with racemic 1-octen-3-ol formed in reaction of linoleate 10S-hydroperoxide with hematin or ferrous ions. The Nostoc linoleate 10S-dioxygenase, the sequence of which contains the signature catalytic sequence of cyclooxygenases and fungal linoleate dioxygenases (YRWH), appears to be a heme dioxygenase ancestor. The novel activity of the lyase expands the known reactions of catalase-related proteins and functions in Nostoc in specific transformation of the 10S-hydroperoxylinoleate.

Behavioral treatment of insomnia: also effective for nocturia.

To evaluate changes in self-reported nocturia in community-dwelling adults aged 60 and older who received behavioral treatment for chronic insomnia. Secondary analysis of a randomized controlled trial of a behavioral intervention for sleep. Academic medical center. Of the 79 enrollees, this analysis focused on 30 who, in addition to insomnia, also reported at least one nightly episode of waking up to void. The brief behavioral treatment of insomnia (BBTI) group (n = 14) received instructions on reducing time in bed and setting a regular sleep schedule. The information control (IC) group (n = 16) received printed materials. A nurse clinician delivered both interventions. Self-reported nocturnal awakenings to void assessed daily for 14 days at baseline and 4 weeks after the intervention. Participants who reported at least one episode of nocturia per night at baseline were included in this analysis. In individuals with nocturia at baseline, the total number of nocturnal voids over the 14-day assessment period decreased by 6.5 ± 4.8 in the BBTI group and increased by 1.3 ± 7.3 in the IC group (P = .04, effect size 0.82). After adjusting for baseline nocturia episodes, the difference remained significant (P = .05). In older adults with concurrent insomnia and nocturia, behavioral treatment directed solely at insomnia may also improve self-reported nocturia. Behavioral treatment of insomnia should be further investigated for its effect on nocturia in individuals with concurrent insomnia and nocturia.

Epitaxial growth of Si1 − xGex alloys and Ge on Si(100) by electron-cyclotron-resonance Ar plasma chemical vapor deposition without substrate heating

By using electron-cyclotron-resonance (ECR) Ar-plasma chemical vapor deposition (CVD) without substrate heating, the epitaxial growth process of Si1−xGex alloy and Ge films deposited directly on dilute-HF-treated Si(100) was investigated. From the reflection high energy electron diffraction patterns of the deposited Si1−xGex alloy (x=0.50, 0.75) and Ge films on Si(100), it is confirmed that epitaxial growth can be realized without substrate heating, and that crystallinity degradation at larger film thickness is observed. The X-ray diffraction peak of the epitaxial films reveals the existence of large compressive strain, which is induced by lattice matching with the Si(100) substrate at smaller film thicknesses, as well as strain relaxation behavior at larger film thicknesses. The Ge fraction of Si1−xGex thin film is in good agreement with the normalized GeH4 partial pressure. The Si1−xGex deposition rate increases with an increase of GeH4 partial pressure. The GeH4 partial pressure dependence of partial deposition rates [(Si or Ge fraction)×(Si1−xGex thickness)/(deposition time)] shows that the Si partial deposition rate is slightly enhanced by the existence of Ge. From these results, it is proposed that the ECR-plasma CVD process can be utilized for Ge fraction control in highly-strained heterostructure formation of group IV semiconductors.

Telomerase-Dependent 3′ G-Strand Overhang Maintenance Facilitates GTBP1-Mediated Telomere Protection from Misplaced Homologous Recombination

At the 3'-end of telomeres, single-stranded G-overhang telomeric repeats form a stable T-loop. Many studies have focused on the mechanisms that generate and regulate the length of telomere 3' G-strand overhangs, but the roles of G-strand overhang length control in proper T-loop formation and end protection remain unclear. Here, we examined functional relationships between the single-stranded telomere binding protein GTBP1 and G-strand overhang lengths maintained by telomerase in tobacco (Nicotiana tabacum). In tobacco plants, telomerase reverse transcriptase subunit (TERT) repression severely worsened the GTBP1 knockdown phenotypes, which were formally characterized as an outcome of telomere destabilization. TERT downregulation shortened the telomere 3' G-overhangs and increased telomere recombinational aberrations in GTBP1-suppressed plants. Correlatively, GTBP1-mediated inhibition of single-strand invasion into the double-strand telomeric sequences was impaired due to shorter single-stranded telomeres. Moreover, TERT/GTBP1 double knockdown amplified misplaced homologous recombination of G-strand overhangs into intertelomeric regions. Thus, proper G-overhang length maintenance is required to protect telomeres against intertelomeric recombination, which is achieved by the balanced functions of GTBP1 and telomerase activity.

Directed formation of silica by a non-peptide block copolymer enzyme mimic.

A non-polypeptide block copolymer inspired by the enzyme silicatein α is shown to template the formation of silica from tetraethoxy orthosilicate (TEOS) in neutral pH and ambient temperature. The block copolymer was synthesized to mimic the chemical functionality shown to be necessary for the function of the natural enzyme. In this report we demonstrate the templating function of the enzyme mimic, the formation of hierarchical structures, the presence of dual mechanisms of condensation at low pH, investigate the mechanism of templation as hydrolyzed species diffuse from the site of hydrolysis, and explore the formation of silica at the polymer surface. Numerous analytical methods are employed in this study, including AFM, TEM, FESEM, DLS, NMR, GPC, and TGA. This bio-inspired polymer combines the features of neutral pH, low temperature, and structure control in silica formation.

Geometric optimization of liquid–liquid slug flow in a flow-focusing millifluidic device for synthesis of nanomaterials

With recent increasing trend towards development of “easy to fabricate” and simple millifluidic systems that could provide required control as well as high throughput, we present here a demonstration of potential opportunities for controlled droplet/slug formation within a flow-focusing millifluidic chip. Numerical simulations supported by experimental evidence show that the millifluidic device provides similar control in slug formation as in the case of microfluidic devices. More specifically, our investigations reveal that the acquired slug volume depends on the squeezing volume (Vsqueeze) and blockage volume (Vblock) in the squeezing regime. While the squeezing volume (Vsqueeze) can be tuned by manipulating the flow rate of the continuous phase, the blockage volume (Vblock) depended only on the geometry of the focusing region. Based on numerical simulations, two millifluidic flow focusing channel designs to produce small slugs were suggested. The slugs were utilized for the synthesis of uniform copper nanoparticles. The findings are anticipated to have implications for a number fields ranging from fluid dynamics, lab-on-a-chip devices, chemical engineering, nanomaterials synthesis, protein crystallization to advanced drug delivery as well as chip fabrication.

Efficacy of Family-Based Weight Control Program for Preschool Children in Primary Care

To test the efficacy of an innovative family-based intervention for overweight preschool-aged children and overweight parents conducted in the primary care setting. Children with BMI ≥ 85th percentile and an overweight parent were randomized to intervention or information control (IC). Trained staff delivered dietary and physical/sedentary activities education to parents over 6 months (10 group meetings and 8 calls). Parents in the intervention received also behavioral modification. An intention-to-treat analysis was performed by using mixed analysis of variance models to test changes in child percent over BMI (%OBMI) and z-BMI and to explore potential moderators of group differences in treatment response. Ninety-six of 105 randomized families started the program: 46 children (31 girls/15 boys) in the intervention and 50 (33 girls/17 boys) in the IC, with 33 and 39 mothers and 13 and 11 fathers in intervention and IC, respectively. Baseline characteristics did not differ between groups. Children in the intervention group had greater %OBMI and z-BMI decreases at 3 and 6 months compared with those assigned to IC (P < .0021). A greater BMI reduction over time was also observed in parents in the intervention compared with parents assigned to IC (P < .0001). Child %OBMI and parent BMI changes were correlated (r = .31; P = .003). Children with greater baseline %OBMI were more likely to have a greater %OBMI decrease over time (P = .02). Concurrently targeting preschool-aged overweight youth and their overweight parents for behavioral weight control in a primary care setting reduced child %OBMI and parent BMI, with parent and child weight changes correlating.

Modern Arab uprisings and social media: An historical perspective on media and revolution

Journalists and other observers claim that new social media brought about the wave of current popular uprisings in the Middle East. This article examines – with an historical perspective within the intellectual framework of media ecology – this idea of new media as the cause of revolution. It concludes that while new media are an important factor behind these recent revolts, they do not cause revolution. Shifts in communication technology have a major influence on the way we interrelate and organize our society. The very structure of the World Wide Web makes control of information extremely difficult for autocratic governments and is indeed a strong force for popular movements, democratic change and freedom.

DYNAMIC MANAGEMENT OF MULTIPLE CLASSIFIERS IN COMPLEX RECOGNITION SYSTEM

There are different kinds of multiple classifiers in complex recognition systems in pursuit of better recognition capabilities. To exploit the classifiers' potential as individual ones sufficiently and enable them to work cooperatively for the best classification results, they need to be considered as a whole and be dynamically managed according to the changing recognition occasions. In this paper, we present the conception of distributed Multiple Classifiers Management (MCM) and a self-adaptive recursive MCM model based on Mixture-of-Experts (ME). A control subsystem is consisted in the model, which allows the classification progress to be controlled by the systems' priori information when necessary. The model adjusts its parameters dynamically according to the current recognition state and gives the recognition results by combining the current individual classifiers' results with the previous combination result under priori information's control. An algorithm based on one step error correction is presented to acquire the model's parameters dynamically. It takes the previous times' ensemble classification results as true and corrects the current weights of the classifiers. At last, an experiment on the recognition of space objects is simulated. The experiment results show that the MCM model in this paper is effective for complex recognition system containing heterogeneous classifiers on improving the recognition rate and robustness.

Review on long-period stacking-ordered structures in Mg-Zn-RE alloys

The recent development of high-strength magnesium alloys is focused on the role of the strengthening phases with a novel long-period stacking-ordered (LPSO) structure. This review detailed the main factors influencing the formation of LPSO phases, including alloying elements, preparation methods, and heat treatments. Furthermore, process control in structure types, formation and transformation behavior, strengthening and toughening mechanisms of the LPSO phase were discussed. Finally, the current problems and development trends of high-strength Mg-Zn-RE alloys were also put forward.