On-off System Research Articles

Pyrene-based luminescent “turn-off” chemosensor on a detonation nanodiamond platform for sensing in aqueous environments

Due to the widespread pollution caused by heavy metals, there is a pressing need for effective monitoring tools to track their distribution and origin in different environments such as wastewater. Chemosensors have emerged as a powerful tool to detect heavy metals in various settings. However, most chemosensors have limited effectiveness and are only functional under specific conditions, such as ultrapure and oxygen free solvents. To overcome this challenge, we introduce here a technique that involves immobilizing water-insoluble chemosensors on detonation diamond nanoparticles, using a pyrene-based on-off system as a model. This method not only improves the sensor's stability but also maintains its efficiency and specificity across diverse media, including unfiltered tap water, organic solvents, and even a pure oxygen atmosphere. Our approach represents a promising solution for developing robust and adaptable nanodiamond-based chemosensor-carrier systems that can detect, e.g. heavy metals in a wide range of environments.

Bioconjugation Between CdTe Quantum Dots and a Cationic Protein: An Analytical Method to Determine Protamine in Drug and Urine Samples

CdTe quantum dots (QD-CdTe) functionalized with mercaptosuccinic acid (MSA) were synthesized in an aqueous medium, varying synthesis time from 0.5 to 4 h. The nanoprobe were characterized by a direct relationship between synthesis time and QD size (2.61-3.04 nm). The QD-CdTe-MSA interacted with protamine (PT), a cationic protein, forming a bioconjugate, thus quenching the photoluminescence intensity and generating an on-off system. The nanoprobe produced at a synthesis time of 1 h (QD-CdTe1) presented PT’s best sensitivity in a succinate buffer (pH = 5). Under the optimized conditions, the proposed method presented a linear range of 0.05-0.5 mg L-1 (10-100 nM), limit of detection (LOD) 0.01 mg L-1 (2 nM), and relative standard deviation (RSD) ≤ 2.01% (n = 10). The interaction of the nanoprobe and PT led to aggregation due to a bioconjugate formation. The systems’ hydrodynamic radius varied from 4.31 nm (QD‑CdTe1) to 30.50 nm for the bioconjugate (QD-CdTe1-PT). The method was sensitive to variation in ionic strength and based on thermodynamic parameters; it was demonstrated that the interaction mechanism occurred preferentially through electrostatic forces. Finally, the method proved to be fast, sensitive, and viable for quantifying PT in drugs and synthetic urine samples with recoveries above 95%.

G-Quadruplex Modulation of SP1 Functional Binding Sites at the KIT Proximal Promoter.

The regulation of conformational arrangements of gene promoters is a physiological mechanism that has been associated with the fine control of gene expression. Indeed, it can drive the time and the location for the selective recruitment of proteins of the transcriptional machinery. Here, we address this issue at the KIT proximal promoter where three G-quadruplex forming sites are present (kit1, kit2 and kit*). On this model, we focused on the interplay between G-quadruplex (G4) formation and SP1 recruitment. By site directed mutagenesis, we prepared a library of plasmids containing mutated sequences of the WT KIT promoter that systematically exploited different G4 formation attitudes and SP1 binding properties. Our transfection data showed that the three different G4 sites of the KIT promoter impact on SP1 binding and protein expression at different levels. Notably, kit2 and kit* structural features represent an on-off system for KIT expression through the recruitment of transcription factors. The use of two G4 binders further helps to address kit2-kit* as a reliable target for pharmacological intervention.

Sistem Kendali Intensitas Cahaya Lampu Penerangan Jalan Umum Menggunakan Transformator Variabel Berbasis Arduino Uno

This research discusses the Arduino Uno based public street lighting intensity control system. The street lighting technology applied so far is still conventional technology that is classified as wasteful of energy because it still uses a continuous lighting system or an On-Off system. PJU problems arise because of too much power consumption caused by the use of large power lamps and lamp operating times. This research utilizes Arduino Uno and RTC to control the value of the variable voltage output transformer based on time division. This system has been able to control the voltage of 400 watt sodium lamps. The output voltage of the transformer has been divided into three levels, namely level 1, level 2 and level 3. The division of this level is based on the operating time of the lights, namely level 1 at 1830 WIB to 2200 WIB, level 2 at 2201 WIB until 2359 WIB, level 3 at 0000 WIB until 0530 WIB. Transformer output voltage at level 1 can be 220 volts. The output voltage of the transformer at level 2 can be 210 volts. Transformer output voltage at level 3 can be 200 volts. The intensity of the 400 watt sodium lamp light at level 1 is an average of 99.9 lux. The intensity of the 400 watt sodium lamp light at level 2 is an average of 85.45 lux. The intensity of the 400 watt sodium lamp light at level 3 is an average of 78.6 lux.

Phosphate-sensing with (di-(2-picolyl)amino)quinazolines based on a fluorescence on-off system.

Detection and visualization of phosphates such as ATP in living organisms can facilitate the elucidation of various biological events. Although substantial efforts had been made in this area, present methods have disadvantages such as the need for specialized equipment and poor sensitivities. To address these limitations, novel fluorescent probes, (di-(2-picolyl)amino)quinazolines, were developed for application in ATP detection. They selectively recognized copper ions by fluorescence quenching, and their copper complexes displayed fluorescence enhancement in the presence of phosphoric acid derivatives. This fluorescence on–off system enabled highly sensitive fluorescence detection of ATP when combined with a phenyl boronic acid-modified γ-cyclodextrin through a plausible multipoint recognition system.

Kontrol Kualitas Kadar Air Laut Menggunakan Fuzzy LogicUntuk Habitat Ikan Kerapu

The quality of the seawater content for the grouper fish habitat is very influential in the grouper fish development process. Seawater quality for grouper fish habitat depend on temperatur, salinity, acidity (pH), and turbidity of seawater. The quality of seawater can be control by circulation in and out of seawater in the fish pond. This cycle is required to maintain the desired quality of seawater at temperatur 24ºC- 31ºC, salinity 30-33 ppt, dissolved oxygen> 3,5 ppt, and pH 7,5-8,3. In previous studies seawater control systems have been carried out in the form of controls temperatur and pH quality. Other components quality of sea water such as salinity and turbidity due to fish food also influence seawater quality for grouper fish habitat. Component control of sea water in this paper include microcontroller, pump sea water, fresh water pump, sensor and etc. In this paper we are focus on the controlling sea water quality to maintain the quality of grouper fish pools consisting of temperatur, salinity, acidity (pH), and turbidity of seawater. Input this data and the pH of the water read by the sensor will be processed with fuzzy logic to adjust the working of the salt water pump and the freshwater pump until it reaches the setpoint value. Turbidity and temperatur control using the ON-OFF system. The results show that of testing the sea water quality of control system using fuzzy logic in accordance with the calculation of mathematical defuzzyfication with an error of 0%. The values of salinity control system 31,14-32,98 PPT, pH 7,78-8,.2, temperatur 27ºC-29,98ºC, and turbidity level 9,90-14,85 NTU.

Measurement of coordinates of sources of radio emission at high frequencies goniometric and goniometric and range-metering by methods

Coordinates of sources of a radio emission of range of high frequencies using an on-off system azimuth and meridian direction finders are measured by a goniometric method. In the bearing posts active arrays of vertical vibrators and synchronized coherent radio receivers with frequency conversion are used. For minimization of amplitude and phase not identities preliminary calibration of channels of the receiver at frequencies of the taken the bearings signals is executed. By results of measurements average quadratic deviations of coordinates of sources of a radio emission of type of radio stations of meteo-information of airfield networks of the Russian Federation and the neighboring countries, standard frequency stations and time, transmitters of telecode and continuous messages are investigated. The analysis of dependences of achievable accuracy figures of measurements on the space provision of positions of direction finders, lengths of routes and also fluctuations of electro-physical parameters and space distribution of the ionized layers of the atmosphere leading to changes of beam trajectories of distribution and abnormal errors of measurements of the directions of arrival of radio waves to different season and day is carried out. It is shown that in the lower part of range of high frequencies the measurement error of coordinates of sources of a radio emission a goniometric system makes 4.7 %, and in process of approach of frequency to the upper bound of range this indicator increases by 1.2 times. By results of bearing of signals in one point of space and measurements of height of layers of the atmosphere with use of the station of vertical sounding coordinates of sources of a radio emission are determined by a goniometric and range-metering method. Measurements of coordinates of objects by a goniometric and range-metering method can be executed with average quadratic deviation of 11-13 % of range.

Stimuli-responsive switchable organic-inorganic nanocomposite materials

Abstract Organic-inorganic nanocomposite materials have attracted a great attention since they cover a wide range of properties by combining the contrasting properties and/or creating novel properties. Functional properties of composites could further be manipulated by stimuli such as light, pH, magnetic/electric field, mechanical force, and heat. When the stimuli can control a wide range of materials’ property, it can be applied to a device with an ON-OFF system: a switch. A switchable material should exhibit the property that is noticeably different upon stimulation (i.e. ON and OFF states) with reversible mechanism. Research on switchable materials has been actively carried out to maximize the difference between ON and OFF states by modifying the structure and composition of nanocomposites, and also on stimuli to control the response time. Switchable materials find their applications in various fields such as catalysts, sensors, photodetectors, memory devices, and drug delivery systems. In this review, we discuss the recent advances in the design/synthesis of organic-inorganic nanoscale materials in which their properties can be controlled in response to a specific stimulus. In addition, we introduce various stimuli (furthermore, multi-stimuli), applications of switchable nanocomposites in a wide range of fields, and also challenges with an outlook.

Bio-Inspired Bright Structurally Colored Colloidal Amorphous Array Enhanced by Controlling Thickness and Black Background.

Inspired by Steller's jay, which displays angle-independent structural colors, angle-independent structurally colored materials are created, which are composed of amorphous arrays of submicrometer-sized fine spherical silica colloidal particles. When the colloidal amorphous arrays are thick, they do not appear colorful but almost white. However, the saturation of the structural color can be increased by (i) appropriately controlling the thickness of the array and (ii) placing the black background substrate. This is similar in the case of the blue feather of Steller's jay. Based on the knowledge gained through the biomimicry of structural colored materials, colloidal amorphous arrays on the surface of a black particle as the core particle are also prepared as colorful photonic pigments. Moreover, a structural color on-off system is successfully built by controlling the background brightness of the colloidal amorphous arrays.

A light-switchable bidirectional expression system in filamentous fungus Trichoderma reesei

The filamentous fungi Trichoderma reesei is widely used in the production of cellulolytic enzymes and recombinant proteins. However, only moderate success has been achieved in expressing heterologous proteins in T. reesei. Light-dependent control of DNA transcription, and protein expression have been demonstrated in bacteria, fungi, and mammalian cells. In this study, light inducible transactivators, a “light-on” bidirectional promoter and a “light-off” promoter were constructed successfully in T. reesei for the first time. Our light inducible transactivators can homodimerize and bind to the upstream region of artificial promoters to activate or repress genes transcription. Additionally, we upgraded the light-inducible system to on-off system that can simultaneously control the expression of multiple heterologous proteins in T. reesei. Moreover, a native cellulase-free background for the expression of heterologous proteins was achieved by knocking out the genes involved in transcriptional regulation and encoding of cellulases: xyr1, cbh1, and cbh2. Our light-switchable system showed a very little background protein expression and robust activation in the blue light with significantly improved heterologous protein expression. We demonstrate that our light-switchable system has a potential application as an on/off “switch” that can simultaneously regulate the expression of multiple genes in T. reesei under native cellulase-free background.

Energy consumption reduction in existing HVAC-R systems via a power law controlling kit

This paper presents an alternative solution for reducing energy consumption in heating, ventilation, air conditioning and refrigeration (HVAC-R) systems. For that, an existing typical commercial refrigeration system was equipped with a novel control system based on a power law, using a frequency inverter and a programmable logic controller (PLC). Hence, it was possible to compare the operation and energy consumption of the system with the power law control and with the on-off system, quantifying the obtained gains. The experimental unit consisted of a cooling chamber, an enclosing chamber (antechamber), and a vapor compression refrigeration system, i.e., an example of a practical commercial cooling system. A set of graphs shows the experimental measurements performed with the two systems. In this way, the measured temperatures in some selected points of the two systems, as well as the consumption in kWh for a period of 6 h and 10 min were compared in the tests. The main conclusions of this work are: i) The system operating with the power law control with respect to the conventional on-off control, showed energy consumption savings of up to 31% in a test period of 6 h and 10 min, and ii) The system compressor cycling frequency in the system operating with the power law control is smaller than with the traditional on-off system. Therefore, the study shows that the developed power law control kit has potential to be installed in any existing system with immediate significant energy savings with no need for HVAC-R hardware changes.

Benefits of pathway splitting in sensory coding.

In many sensory systems, the neural signal splits into multiple parallel pathways. For example, in the mammalian retina, ~20 types of retinal ganglion cells transmit information about the visual scene to the brain. The purpose of this profuse and early pathway splitting remains unknown. We examine a common instance of splitting into ON and OFF neurons excited by increments and decrements of light intensity in the visual scene, respectively. We test the hypothesis that pathway splitting enables more efficient encoding of sensory stimuli. Specifically, we compare a model system with an ON and an OFF neuron to one with two ON neurons. Surprisingly, the optimal ON-OFF system transmits the same information as the optimal ON-ON system, if one constrains the maximal firing rate of the neurons. However, the ON-OFF system uses fewer spikes on average to transmit this information. This superiority of the ON-OFF system is also observed when the two systems are optimized while constraining their mean firing rate. The efficiency gain for the ON-OFF split is comparable with that derived from decorrelation, a well known processing strategy of early sensory systems. The gain can be orders of magnitude larger when the ecologically important stimuli are rare but large events of either polarity. The ON-OFF system also provides a better code for extracting information by a linear downstream decoder. The results suggest that the evolution of ON-OFF diversification in sensory systems may be driven by the benefits of lowering average metabolic cost, especially in a world in which the relevant stimuli are sparse.

Preview suspension control for a full tracked vehicle

In this study, preview control algorithms for the active and semi-active suspension systems of a full tracked vehicle (FTV) are designed based on a 3-D.O.F model and evaluated. The main issue of this study is to make the ride comfort characteristics of a fast moving tracked vehicle better to keep an operator’s driving capability. Since road wheels almost trace the profiles of the road surface as long as the track doesn’t depart from the ground, the preview information can be obtained by measuring only the absolute position or velocity of the first road wheel. Simulation results show that the performance of the sky-hook suspension system almost follows that of full state feedback suspension system and the on-off semi-active system carries out remarkable performance with the combination of 12 on-off semi-active suspension units. The results simulated with 1st and 2nd weighting sets mean that the suspension system combined with the soft type of inner suspension and hard type of outer suspension can carry out better ride comfort characteristics than that with identical suspensions. The full tracked vehicle (FTV) system is uncontrollable and the system is split into controllable and uncontrollable subspace using singular value decomposition transformation. Frequency response curves to four types of inputs, such as heaving, pitching, rolling, and warping inputs, also demonstrate the merits of preview control in ride comfort. All the frequency characteristic responses confirm the continuous time results.

Research on Bit Error Rate in the Presence of Local Wavefront Aberration in Intersatellite Laser Communications

Local distortions in lenses of transmitter optical system could further deteriorate the performance of intersatellite laser communications (lasercom). Bit error rate (BER) for on-off keying system is investigated considering the combined influence of local distortion and pointing error, without considering the noise of the detector. It is shown that BER varies regularly with the characteristic parameters of local distortion. Peak-to-valley value that is usually used to evaluate lens machining precision is determined, and the key principles for selecting lenses are given. This paper can contribute to the lasercom system design.

SPN-Based Performance Evaluation for ON-OFF Voice Traffic System

By taking voice traffic system as study object, mathematical modeling methodology was used to investigate different parameters’ variations on system’s performance. Firstly, on the basis of analyzing the characteristics of voice traffic, this paper constructed a Stochastic Petri Net (SPN) model for ON-OFF voice traffic system. Furthermore, average time delay of the system was analyzed and model-based simulation was conducted with Stochastic Petri Net Package (SPNP) 6.0. For different parameters of ON to OFF rate and user’s voice connections, variation trends of number of user’s connections and ON to OFF rate are derived thereby. The methodology of modeling and simulation in this paper can be further used to analyze the performance of multimedia hybrid traffic system.

Synthesis of the Functional Hydrogels: Poly(N-isopropylacrylamide) Threaded onto the PEG Backbones Via RAFT

Functional poly(N-isopropylacrylamide) (PNIPAM) hydrogels were prepared by reversible addition fragmentation chain transfer (RAFT) polymerization of NIPAM in the presence of four-arm poly(ethylene glycol) (4A-PEG) as backbone and 4-cyanopentanoic acid dithiobenzoate functional α -cyclodextrin threaded onto the PEG as chain transfer reagent (CTA).The structure of the hydrogels was characterized in detail with FTIR techniques. The analytical results demonstrated that α -cyclodextrin remains in as-obtained hydrogels. The swelling behavior was investigated and the functional hydrogels (functional gels) showed accelerated shrinking kinetics and higher swelling ratio comparing with conventional hydrogel (CG). It could be attributed to the presence of dangling chains. The hydrogel exhibited rapid swelling and deswelling kinetics. In principle, the hydrogel might find a number of applications including an on-off system and drug delivery systems.

Energy saving in agricultural buildings through fan motor control by variable frequency drives

A comparison was conducted between ON–OFF and variable frequency drive (VFD) systems to control ventilation fans of greenhouses and poultry houses. The study aimed to determine the effect of each system on the energy consumption and resulting microclimate within the houses. The experiments were carried out in a commercial-size greenhouse in which pepper was grown and in commercial poultry houses. Reducing the fan speed with the VFD system resulted in reductions in the airflow rate through the houses and energy consumption, the latter being much more significant. The study showed that VFD control can reduce electricity consumption compared with ON–OFF operation. In the present study, the average energy consumption with the VFD control system was about 0.64 and 0.75 of that with an ON–OFF system in the greenhouse and poultry houses, respectively. The average greenhouse daily air temperatures and humidity ratios obtained with each control system between 07:00 and 18:00 were nearly equal. The results obtained in the greenhouse further showed that the VFD system has a greater potential than the ON–OFF, to reduce the range of amplitude variations in the air temperature and humidity ratio within the greenhouse. The average air temperatures over day and night, in the poultry houses, with each control system were nearly equal. The relative humidity, however, was slightly lower with VFD than with ON–OFF. Reductions in the range of amplitude variations of the air temperature and humidity were also observed in the poultry houses.

A Novel System for Organ and Tissues Preservation: The Refrigerating Hyperbaric Chamber

This study was designed to investigate the feasibility of building a simple and inexpensive device to preserve organs or tissues in hyperbaric and hypothermic conditions. Methods The device was built on a 40-cm wide, 28-cm long, and 23-cm deep stainless steel chassis. The pressure vessel was built by a 7.8-cm bore stainless steel cylinder put inside another 12-cm cylinder welded together and closed by a steel plate on the top and bottom. The inferior plate was welded, and the superior one was fixed by manual clasp nut. The cooling system is made up of air compressor, condenser, expansion area, and cooling worm that is located between the cylinders. The temperature-controlling device is a computer processor contained in an integrated-circuit chip, with a on-off system to maintain the chamber temperature between 2° to 4°C. The compression of the chamber is performed by lateral coupling with the oxygen cylinder and is maintained at 5.5 absolute atmospheres and controlled by air pressure gauge. The maximal work pressure was evaluated by spreadsheet. Temperature or pressure changes were evaluated by 12- and 24-hour assays. Results The maximal work pressure permitted was 6.5 absolute atmospheres. Thus, the container was free from danger. The temperature inside the chamber was kept between 2° and 4°C. The production costs of the prototype was US$1000. Discussion The manufacture of the refrigerating hyperbaric chamber is viable, simple, and inexpensive.

Effect on energy use and greenhouse microclimate through fan motor control by variable frequency drives

A comparison was conducted between ON–OFF and variable frequency drive (VFD) systems to control greenhouse ventilation fans. The study aimed to determine the effect of each system on the energy consumption and resulting greenhouse microclimate. The experiments were conducted in a commercial size greenhouse in which pepper was grown. To check the performance of the fan that was controlled by a VFD system, it was installed in a test facility and operated under several rotation speeds. At each speed of rotation, the static pressure on the fan was changed and parameters, such as electricity consumption and air flow rate, were measured. Reducing the fan speed with the VFD system resulted in reductions in the air flow rate through the greenhouse and energy consumption, the latter being much more significant. The study showed that VFD control can reduce electricity consumption compared with ON–OFF operation by an amount that depends on the weather. In the present study, the average energy consumption with the VFD control system over a period of one month, was about 0.64 of that with an ON–OFF system. The average greenhouse daily air temperatures and humidity ratios obtained with each control system between 0700 and 1800 were nearly equal during that month. The results obtained in the greenhouse further show that the VFD system has a greater potential than the ON–OFF to reduce the range of amplitude variations in the air temperature and humidity ratio within the greenhouse.

Do rapid systemic changes of brain temperature have an influence on the brain?

The purpose of the present study was to examine the influence of cooling and rewarming conditions using an accurate brain temperature control system. The brain temperature of animals was measured with a thermometer while feedback regulation was achieved with a cold (4( degrees )C) and hot (50( degrees )C) water on-off flow system. Brain temperature was well controlled throughout the experiment by using both cold water and hot water simultaneously. Three groups were studied, as follows: 1) the standard group (cooled to 24( degrees )C for 1 hour, kept at 24( degrees )C for 2 hours and rewarmed to 37( degrees )C for 1 hour), 2) the rapid-cooling group (cooled to 24( degrees )C for 30 min, kept at 24( degrees )C for 2 h, and rewarmed to 37( degrees )C for 1 h), 3) the rapid-rewarming group (cooled to 24( degrees )C for 1 h, kept at 24( degrees )C for 2 h, and rewarmed to 37( degrees )C for 30 min) and the normal-control group. An increase of MAP-2 immunoreactivity of the CA1 neurons in the dorsal hippocampus was observed one week but not one month after hypothermia in the rapid-rewarming group. There was also a significant increase in the glutamate and lactate value at the end of rewarming compared with the baseline in the rapid-rewarming group (p<0.01). Our results suggest that rapid rewarming after hypothermia triggered an uncoupling of cerebral circulation and metabolism, inducing an increase of extracellular glutamate and lactate, consequently reversible neuronal cell damage.