224 results about "Biochemical reactions" patented technology

The invention relates to the technical field of sewage treatment, in particular to an aerobic aeration treatment system for plateau domestic sewage treatment, which comprises a pretreatment unit, a biological treatment unit, an advanced treatment unit and a recycling unit which are connected in sequence, the system further comprises a data acquisition module, an aerobic aeration intelligent regulation and control module, a biochemical environment constant-temperature maintenance module, a carbon-nitrogen proportion and backflow dynamic regulation and control module, a digital twinning and sludge characteristic simulation module and an energy collaborative scheduling module. Compared with the prior art which adopts a standard aeration strategy and cannot adapt to the special environment of low air pressure and low oxygen partial pressure of the plateau, the system can accurately adapt to the plateau environment by integrating real-time atmospheric pressure and water temperature monitoring, dynamically calculating the oxygen saturation solubility and correcting the aeration control target according to the oxygen saturation solubility, so that the aeration control target is optimized. Stable supply of dissolved oxygen required by biochemical reaction is ensured, and the technical bottleneck of low efficiency of traditional sewage treatment in plateau regions is fundamentally overcome.

The invention discloses a membrane filtration sewage treatment system based on fine control, relates to the technical field of sewage treatment, and solves the technical problems of delayed response to water quality and water quantity fluctuation and extensive biochemical reaction control caused by water inlet load impact in an existing sewage treatment system. The system comprises an inflow water pretreatment module used for predicting inflow water quality in real time by using a water quality prediction model based on a neural network, and carrying out water quantity balance and water quality adjustment on inflow water according to a prediction result to obtain a first water body; the biochemical reaction module is used for cooperatively controlling external carbon source addition, nitrification liquid backflow and aeration intensity in the biological reaction process of the first water body by utilizing a multivariable model predictive control method to obtain a second water body after biochemical reaction; and the deep purification module is used for carrying out solid-liquid separation and deep purification on the second water body to obtain an effluent water body, and triggering cleaning and maintenance operation of the membrane based on a prediction result of the membrane pollution characteristics.

The invention belongs to the technical field of biochemical pharmacy, and particularly relates to a bezoar intermediate and a preparation method of bezoar. The preparation method comprises the following steps: mixing preparation raw materials and biochemical reaction liquid to obtain a mixed raw material solution; the preparation raw materials comprise bilirubin, organic active raw materials and vitamins, the biochemical reaction liquid is sterile purified water, and the bilirubin comprises bilirubin or biliverdin; and reacting the mixed raw material solution to obtain the bezoar intermediate. The content of combined bilirubin in the bezoar intermediate prepared by the preparation method provided by the invention is 75%-85%, the content of combined biliverdin is 73%-83%, and the yield is 83%-87%. According to the method, the poisoning and destroying effects of mycotoxin on the content, the yield, the biological activity and the oxidation resistance of the bezoar intermediate are effectively eliminated. The content, the yield, the oxidation resistance and the biological activity of the bezoar intermediate are greatly improved, the performance is stable, and the quality of bezoar is ensured.

An integrated slide, a liquid changing device, a biochemical substance analysis system and an analysis method.The integrated slide comprises a biochip and an ink jet chip packaged above the biochip, the biochip and the ink jet chip define a biochemical reaction cavity, the ink jet chip is communicated with the biochemical reaction cavity, and the biochemical reaction cavity is communicated with the liquid changing device. Reagents required by biochemical reaction can be added into the biochemical reaction cavity, or reacted residual reagents in the biochemical reaction cavity can be discharged; and the biochip can realize in-situ signal detection. According to the biochemical substance analysis system applying the integrated slide glass, integrated operation of sample adding, biochemical substance analysis and imaging can be realized, the system structure is simplified, the reagent loss is reduced, the detection efficiency is favorably improved, and the detection cost is reduced.

The invention relates to a process for degrading thiocyanate radicals in carbon leaching tailing wastewater by a plug flow type aerobic sludge method. A process for degrading thiocyanate radicals in carbon leaching tailing wastewater by a plug-flow aerobic sludge process comprises the following steps: (1) pretreatment: adding an iron-containing agent into the carbon leaching tailing wastewater to carry out a primary cyanide breaking reaction, after the reaction is finished, settling by a thickener 1, carrying out filter pressing, and separating out filter pressing residues and filter pressing liquid; (2) carrying out multi-stage buffer and sedimentation treatment on the press filtrate to obtain overflow water; (3) introducing the overflow water into a plug flow type aerobic aeration tank, and introducing a compound flora to carry out biochemical reaction; and (4) after the reaction is finished, precipitating the water in the plug-flow aerobic aeration tank to obtain supernate and bottom sludge. According to the process for degrading the thiocyanate radicals in the carbon leaching tailing wastewater by the plug flow type aerobic sludge method, the wastewater treatment effect and the treatment capacity can be greatly improved through the treatment mode of pretreatment, multi-stage buffering and biodegradation, gold recovery is achieved, and great economic benefits are achieved.

1. Name of the product in this design: Vertical carbon dioxide refrigeration unit. 2. Purpose of this design: To relieve pain and swelling by stimulating the skin and subcutaneous blood with low temperature, thereby facilitating a series of biochemical reactions in the human body and achieving sports recovery. 3. The key design features of this product are the combination of shape and pattern. 4. The image or photograph that best illustrates the design's key points: a 3D model.

This invention relates to the field of industrial wastewater treatment technology, specifically a highly efficient treatment method for methionine wastewater, comprising the following steps: Step 1: pH adjustment, adjusting the pH of the methionine wastewater to 6.0-7.0; Step 2: Polyferric sulfate coagulation and sedimentation, adding polyferric sulfate and polyacrylamide to the pH-adjusted wastewater; Step 3: Pre-stage ozone oxidation, passing the supernatant obtained in Step 2 through ozone-containing gas for oxidation treatment; Step 4: Biochemical treatment, subjecting the effluent from Step 3 to a biochemical reaction, sequentially passing through anoxic and aerobic stages; Step 5: Post-stage ozone oxidation, passing the biochemical effluent obtained in Step 4 again through ozone-containing gas for deep oxidation treatment; Step 6: Activated carbon adsorption. The methionine wastewater treated by this invention can significantly reduce TOC concentration and improve COD removal rate. The pH pre-adjustment step effectively reduces the quenching effect of alkalinity on hydroxyl radicals, ensuring the efficiency of subsequent advanced oxidation processes.

The present application relates to a kind of coking wastewater advanced treatment method and system, method includes: the water quality characteristics of coking wastewater are pre-configured with modified polyurethane suspended filler, modified anode electrode and modified fly ash filler;Coking wastewater is sent into biochemical pool and carries out biochemical reaction, and modified polyurethane suspended filler is placed in biochemical pool;The effluent of biochemical pool is sent into electro-catalytic oxidation device and carries out electrolysis reaction, and electro-catalytic oxidation device uses modified anode electrode as anode electrode, and uses graphite electrode as cathode electrode;The effluent of electro-catalytic oxidation device is sent into filler adsorption tower and carries out adsorption treatment, and modified fly ash filler is placed in filler adsorption tower.The present application is pre-configured with modified polyurethane suspended filler, modified anode electrode and modified fly ash filler for coking wastewater advanced treatment for the water quality characteristics of coking wastewater, can economically and efficiently reduce the content of TOC, total fluorinated alkyl compound and total cyanide in coking wastewater.

The utility model discloses a biochemical reaction tank, which relates to the technical field of biochemical reaction tank structures and aims to solve the problem that the use effect of the biochemical reaction tank is affected due to poor aeration effect of the existing biochemical reaction tank. A feeding chamber is arranged in the biochemical reaction box, a sewage inlet seat is arranged on one side of the outer wall of the biochemical reaction box, a sewage inlet pipeline is mounted in the feeding chamber, a communicating hole is formed in one end of the feeding chamber, a biochemical chamber is arranged on one side of the feeding chamber, and a mounting frame is mounted in the biochemical chamber; a second filtering baffle is mounted above the mounting frame, a treatment chamber is arranged on one side of the biochemical chamber, and an aeration chamber is arranged on one side of the biochemical chamber.

The invention relates to processes for performing biochemical reactions, such as in an aqueous in vitro reaction system. The processes involve macromolecules, particularly polypeptides, comprising one or more functional intrinsically disordered regions (IDRs). The invention also relates to IDR-macromolecules, including IDR-polypeptides, including macromolecules or polypeptides comprising a tagged amino acid sequence which comprises or consists of one or more functional IDRs. Such functional IDRs are capable of increasing the efficiency of the biochemical reaction. The invention relates to kits comprising any such macromolecules and polypeptides. The invention further relates to processes for stimulating or enhancing liquid-liquid demixing in a solution using any such macromolecules and polypeptides, including in combination with multivalent metal ions, thereby providing reagents capable of increasing the efficiency of a biochemical reaction.

The application provides a sewage treatment biochemical reaction tank, and relates to the technical field of sewage treatment, which comprises a biochemical tank, wherein the biochemical tank is communicated with a water distribution tank, a plurality of filter material oxidation units are arranged in the biochemical tank, adjacent filter material oxidation units are communicated, sewage enters from one end of the biochemical tank, sequentially passes through a plurality of adjacent filter material oxidation units, and finally enters a sedimentation tank, the filter material oxidation unit comprises a filter material bin and an oxidation tank, the filter material bin is filled with granular calcium carbonate dephosphorization filter material so as to remove phosphate ions in sewage, an aeration pipe is arranged below the oxidation tank, a plurality of aeration holes are formed in the aeration pipe, a curtain type filler is arranged above the aeration pipe, and the curtain type filler is attached with an aerobic microbial membrane; the filter material bin is arranged adjacent to the oxidation tank, and the oxidation tank is communicated with the filter material bin. The application has the advantages of high dephosphorization and denitrification efficiency and good sewage treatment effect.

This invention relates to an advanced oxidation-biological co-treatment system and method for mineral processing wastewater. The advanced oxidation-biological co-treatment method for mineral processing wastewater of this invention includes the following steps: S1: Introducing polymetallic mineral processing wastewater into a pretreatment tank and adjusting the pH value for initial sedimentation treatment; S2: Introducing the supernatant into a coagulation sedimentation tank and adding a coagulant for secondary sedimentation treatment; S3: Introducing the supernatant into an ozone catalytic oxidation tower, adding a catalyst, and performing oxidation treatment to remove toxic and recalcitrant substances, and then removing residual ozone; S4: Introducing the wastewater into a biochemical reactor for biological treatment, followed by sludge settling, and discharging the supernatant after it meets the standards. The advanced oxidation-biological co-treatment method for mineral processing wastewater of this invention selectively catalytically oxidizes the wastewater before biological treatment, thereby improving the biodegradability of the wastewater.

The application provides an integrated biochemical reaction tank and a sewage treatment system, and belongs to the field of sewage treatment, wherein the integrated biochemical reaction tank comprises a reaction tank body and an aeration assembly; the reaction tank body is in a cylindrical shape, and a sewage inflow port is arranged at the bottom; the aeration assembly comprises a first mounting shaft, an aeration cross pipe, a gas supply pipeline, a liquid supply pipeline and a direction adjusting mechanism; the direction adjusting mechanism is used for controlling the orientation of the nozzle of the aeration cross pipe; and the first mounting shaft can drive the aeration cross pipe to move up and down. Compared with the prior art, the aeration assembly is improved, anaerobic, facultative and aerobic are integrated in one tank body, the length of different reaction sections in the reaction tank can be changed through the axial movement of the first mounting shaft, and then the distribution ratio of the anaerobic section, the aerobic section and the anoxic section can be adjusted according to the specific condition of the sewage.

The invention relates to the technical field of Internet of Things and fresh agricultural product quality tracing, in particular to a plastic fruit tray quality tracing system based on the Internet of Things. Comprising a multi-modal data acquisition unit configured to acquire microscopic physical stress associated data, mesoscopic interface environment data, macroscopic biochemical state data and hidden environment factor data in real time; the key parameter calculation unit is configured to be used for calculating an interface biochemical amplification coefficient and calculating vibration energy and illumination energy; the positive feedback avalanche risk assessment model unit is configured to be used for resolving normalized accumulated release stress and normalized ethylene release flux and generating an avalanche risk index; and the early warning and decision support unit is configured to be used for outputting risk early warning based on the avalanche risk index. The system deeply reveals and quantifies the positive feedback avalanche mechanism between the physical stress and the biochemical reaction, and overcomes the limitation that the traditional macroscopic parameter monitoring cannot predict sudden and mass putrefaction.

The utility model provides an integrated two-stage AO biochemical reaction device. According to the integrated two-stage AO biochemical reaction device, an intermediate sedimentation tank of a conventional two-stage AO biochemical treatment process is omitted. Through the arrangement that the anaerobic reaction tank and the anoxic reaction tank are filled with biological stuffing and the setting of large-flow internal reflux sludge, the output of the sludge is reduced, so that the sludge entering the second-stage AO biochemical treatment tank is not too much to influence the operation of the second-stage AO biochemical treatment tank even if an intermediate sedimentation tank is not arranged. According to the treatment device disclosed by the utility model, an improved and simplified secondary A / O wastewater treatment system is integrally arranged in an integrated treatment device, so that the optimization and integration of a treatment process are realized, the treatment effect can be improved and better guaranteed, the occupied area of a treatment structure is minimized, and the treatment cost is reduced. And the construction period and the construction cost can be greatly reduced. The utility model provides an efficient, reliable and economical treatment device for the treatment of high-concentration organic wastewater.

The invention relates to the technical field of petrochemical engineering analysis, and provides a form analysis method and system for sulfides in a sulfuric acid alkylation working solution, and the analysis method comprises the following steps: S1, sample collection and pretreatment; s2, carrying out derivatization reaction; s3, separating and detecting; s4, data processing and analysis; the system comprises a sample pretreatment module, a derivatization reaction module, a separation detection module and a data processing and analysis module, and the analysis method provided by the invention can accurately and quickly analyze the forms and contents of various sulfides in the working solution, is high in sensitivity and accuracy, simple, convenient and quick to operate, has good universality and expansibility, and can be widely applied to industrial production. The method is suitable for qualitative and quantitative analysis of various sulfide forms in the field of petrochemical engineering, and has important industrial application value.

The utility model relates to a decarburization biological filter which comprises a filter body and an aeration pipeline, and an aerobic filler layer and a hydrolytic acidification filler layer which are layered up and down are arranged in the filter body and are both filled with iron-carbon-based biological carrier filler. Wastewater enters from a water inlet at the bottom of the tank and flows through the hydrolytic acidification layer, iron-carbon filler releases ferrous ions and reducing active substances through a micro-electrolysis reaction in an anaerobic environment, macromolecular organic matters are decomposed into micromolecular fatty acids in cooperation with hydrolytic acidification florae, and water flows into the aerobic layer and flows into the aerobic layer. Aerobic microorganisms attached to the surface of the filler mineralize small-molecular organic matters into carbon dioxide and water under aeration oxygen supply, ferrous ions are oxidized into iron ions and flocculate and adsorb pollutants, hydroxyl radicals generated by micro-electrolysis oxidize refractory substances, the iron ions precipitate and flow back to the lower layer to form circulation, and the pollutants are recycled. A symbiotic reaction system is constructed through electron transfer between filler layers and the synergistic effect of microorganisms, deep coupling of physicochemical and biochemical reactions is achieved, the removal efficiency of refractory pollutants is remarkably improved, and the technological process is simplified.

This invention provides a biomass fuel and its preparation method, belonging to the field of waste utilization technology. This invention mixes different waste materials to prepare biomass raw materials, and simultaneously utilizes microbial strains to transform the organic flame retardants contained in the waste raw materials into new flammable agents through biochemical reactions. The prepared biomass fuel has high calorific value, low smoke and dust, and excellent combustion performance, making rational use of various waste materials, and is environmentally friendly, efficient, and energy-saving. The results of the embodiments show that the biomass fuel prepared by this invention has a calorific value of 35.6 MJ / kg, a calorific value of 4100 cal / g, a combustion efficiency of 99.1%, and low smoke and dust.

The invention belongs to the field of biochemical reaction, and particularly relates to a biochemical reaction integrated device which comprises a supporting steel frame; a biochemical tank; the biochemical tank is fixedly connected to the side edge of the supporting steel frame; a linkage reaction mechanism; the linkage reaction mechanism is arranged in the biochemical tank and is used for triggering air blowing in in a linkage manner while accelerating the biochemical reaction. By means of the linkage reaction mechanism, air is blown in from the bottom of the biochemical tank through the exhaust pipe and collides and shears with reaction liquid which is strongly stirred by the stirring blades in the bottom area, large bubbles are rapidly broken into tiny bubbles, and the tiny bubbles are evenly dispersed into the whole biochemical tank along with turbulent flow. And the gas-liquid contact area and time are maximized, so that the biochemical reaction period is greatly shortened.

The present application discloses a fluidic system, a control method, a sequencing system, and a storage medium. The fluidic system includes a reaction device, a pipeline, and a degassing device. The reaction device is configured to provide a site for carrying out biochemical reactions. The pipeline is in communication with the reaction device and configured to deliver liquid to the reaction device and / or receive liquid flowing out from the reaction device. The degassing device is connected to the pipeline and configured to remove gas from the liquid in the pipeline. In this way, by removing gas from the liquid in the pipeline using the degassing device, the formation of bubbles in the reaction device can be reduced.

The application relates to a sewage treatment system and a treatment method. The sewage treatment system comprises a biochemical reaction device and a feeding device. The biochemical reaction device comprises at least one set of reaction modules. The reaction modules comprise a plurality of reaction units. Each reaction unit of each reaction module is communicated with at least another reaction unit through a communication component. The feeding device is communicated with each reaction unit respectively. The feeding device can feed adsorbing materials to each reaction unit respectively. The application provides a sewage treatment system and a treatment method, which can improve the removal effect of small-molecule organic matters in sewage.

The utility model provides an aquaculture container which comprises a container body, an aquaculture system and a circulating water treatment system. A culture area and a water treatment area are arranged in the box body, and the culture area and the water treatment area are arranged in the length direction of the box body. The culture system is arranged in the culture area and comprises an aquaculture pond, and the aquaculture pond is provided with a blow-off pipe. The circulating water treatment system is arranged in the water treatment area and comprises a horizontal pipe precipitation separation device, a biochemical reaction device, a microfiltration device and a sterilization device. According to the aquaculture container, the aquaculture system and the circulating water treatment system are integrated in the container body, and the aquaculture container is reasonable in arrangement, compact in structure, high in space utilization rate, capable of being installed and operated after being directly transported to a destination, low in construction cost and short in construction period.

Protein and RNA-based condensates are emerging as an alternative to classical membrane-bound organelles for the task of compartmentalizing molecules and biochemical reactions. We describe methods for making RNA condensates in mammalian cells. We further show that aptamers make it possible to recruit peptides and proteins to the condensates with high specificity. Such RNA condensates can be modularly customized and offer a route toward creating systems of functional artificial organelles.

The present disclosure provides methods that enable sequence-specific nucleic acid amplification in-situ using photo-switchable molecular constructs. The sample comprising target nucleic acids is exposed to pulsed photon fluxes with different wavelengths to actuate the photo-switchable molecular constructs that trigger and / or halt specific biochemical reactions resulting in amplifying the specific nucleic acid sequences in a linear or exponential fashion.

The invention belongs to the technical field of biochemical pharmacy, and particularly relates to a compound bezoar composition, decoction piece type compound bezoar and a preparation method of the decoction piece type compound bezoar. The compound calculus bovis composition provided by the invention comprises 94-96% by mass of main agents and 8 kinds of calculus bovis intermediates, the mass content of the auxiliary agent is 4-6%, and the auxiliary agent is six commercially available finished product combined cholic acid. The bilirubin content of the bezoar intermediate used in the invention is increased by more than 30% and the yield is increased by more than 25% compared with the existing biochemical reaction process of oxgall. The DPPH free radical scavenging rate of the compound bezoar composition reaches 89.6% + / -2.1% and is increased by 25.7-36.9% compared with 58.3% + / -3.5% of a product prepared from ox bile, and through t inspection, p is smaller than 0.01 (n is equal to 5). Free cholic acid intervention is strictly prohibited, lithocholic acid addition is completely eradicated, and the composition has the advantages of being high in bilirubin content, high in oxidation resistance and high in biological activity and adapts to the physiological characteristics of the human body.

A computational system and method for digital modeling of biochemical reactions within cardiac cells are disclosed. The system comprises processors and a computer-readable storage device with instructions to maintain biological data related to cardiac cell reactions and receive user selections via a user interface to configure a simulation. The user can select a cardiac cell class, and functions to load cellular components, generate enzyme activity, load specific enzymes, and perform enzymatic reactions. The system performs in silico experiments, predicts new biological data, and compiles this into configuration data. An enzyme activity model is generated and simulated under various conditions, including user-defined enzymatic dysregulation, to replicate and study cardiac physiology and pathology. The results, such as changes in energy metabolism parameters like glucose consumption and ATP usage, are outputted. The system provides a detailed and interactive platform for research and education in cardiac electrophysiology and disease.

The utility model discloses a wastewater treatment device and belongs to the technical field of battery recovery. The system comprises a high-temperature acidolysis tank, a calcium adding reaction tank, a first filter press, a wastewater adjusting tank, a settling pond unit, a second filter press and a biochemical treatment unit. Discharge wastewater is subjected to acidolysis through a high-temperature acidolysis tank and then added into a calcium-adding reaction tank for a calcium-adding reaction, filtrate obtained by filtering through a first filter press and NMP wastewater are added into a wastewater adjusting tank for homogeneous and average adjustment treatment, and obtained mixed wastewater enters a sedimentation tank unit for calcium removal; and filtering the precipitate by the second filter press to obtain a filtrate, and introducing the filtrate into a biochemical treatment unit for biochemical reaction treatment to obtain a preset liquid. After the liquid is detected to meet the sewage discharge standard, the liquid can be discharged, so that the combined treatment of the discharge wastewater and the NMP wastewater can be realized, the equipment investment is reduced, the treatment cost is reduced, and the industrialization is realized.

The application discloses a sewage treatment system and method, and relates to the technical field of sewage treatment, which comprises a biochemical reaction unit and a sludge-water separation unit. The outlet of the biochemical reaction unit is communicated with the inlet of the sludge-water separation unit. The biochemical reaction unit is used for outputting a mixed liquid to be separated, and the sludge concentration of the biochemical reaction unit is controlled to be 5000 mg / L-10000 mg / L. The sludge-water separation unit comprises a dewatering machine. The sludge concentration of the feed mixed liquid of the dewatering machine is controlled to be 5000 mg / L-10000 mg / L. The dewatering machine is used for sludge-water separation, and the water content of the wet sludge after separation is 75%-85%. The dewatering machine has a water outlet and a wet sludge outlet. The sewage treatment method provided by the application is implemented by using the sewage treatment system. The application can reduce the land occupation, control the cost, and maintain stable sludge-water separation effect.

The invention relates to the technical field of industrial internet, and discloses a big data driven tea industry full-chain intelligent model and visualization method, which comprises the following steps: firstly, constructing a full life cycle process topology network according to a process formula of a production batch and production line metadata, and mapping heterogeneous sensing data into a unified event stream; then establishing a polymorphic coupling digital twin containing biochemical reaction and material rearrangement operators according to a stacking processing link; local linearization and spatial modal decomposition are carried out on the twin body, a mask matrix representing a monitoring blind area is extracted, and a recessive quality out-of-control proportion index is calculated in combination with real-time state energy distribution statistics; and finally constructing a structured digital certificate based on the index and writing the structured digital certificate into the block chain. According to the method, the structural unobservable risk in the pile processing process can be quantified, and visual early warning and credible evidence storage of hidden quality fluctuation are realized.

The utility model relates to a multi-stage composite integrated closed biochemical reaction device, which adopts a steel storage tank structure and divides a tank body into three parts, namely a settling zone, an inner-ring hydrolytic acidification zone and an outer-ring fluidized bed biochemical zone. The settling zone is positioned above the storage tank and is used for separating activated sludge; the inner-ring hydrolytic acidification area is arranged below the settling area and is uniformly divided into multiple stages of hydrolytic acidification chambers through partition plates, and suspended filler is mounted at the upper part of the inner-ring hydrolytic acidification area, so that sewage is in full contact with a biological membrane; the outer-ring fluidized bed biochemical area surrounds the inner-ring hydrolytic acidification area and is composed of multiple stages of fluidized bed reaction chambers, steady-flow gas guide diffusion cones, strong-mixing demolding oxygenation pipes, rotary-cut aerators and the like are arranged in all the chambers, and efficient degradation of organic pollutants, ammonification of organic nitrogen and nitrification-denitrification nitrogen removal of ammonia nitrogen are achieved through alternate ascending and descending reciprocating flow of water flow. The structure integrates precipitation, reaction and circulation, not only improves the mass transfer and microorganism contact efficiency in the reactor, but also is small in occupied area, low in energy consumption, stable in operation and simple and convenient to maintain.