34 results about "Salt pan" patented technology

The invention relates to the technical field of underground brine mining, and specifically provides a closed underground brine mining system and a construction method thereof. The closed underground brine mining system includes a gas compression device, a first water isolation layer, a second water isolation layer, a brine storage layer, partition walls, brine drainage wells and water isolation dams, wherein the brine storage layer, the partition walls, the brine drainage wells and the water isolation dams are located between the first water isolation layer and the second water isolation layer. The upper ends of the partition walls extend to the first water isolation layer, the lower ends of the partition walls extend to the second water isolation layer, and the partition walls, the firstwater isolation layer, the second water isolation layer and the water isolation dams divide the brine storage layer into a plurality of enclosed spaces. Each enclosed space is a brine mining block. Agas compression well is arranged at the position, near the center of a lake, in each brine mining block, the brine drainage wells are arranged at the positions, near the edge of the lake, in the brinemining blocks, the brine drainage wells are provided with brine drainage pipes, and brine can be drained through the brine drainage pipes and then directly transported to salt pans or grit chambers.The closed underground brine mining system can reduce the cost of brine mining, greatly increases the mining amount of the brine, and improves the mining efficiency and increases the recovery rate.

The invention relates to a coastal zone regional function long time sequence identification method based on multi-source big data, and the method comprises the following steps: firstly, constructing coastal zone regional function land classification based on human production, life and ecology, and carrying out the initial classification of a long time sequence image through employing a random forest algorithm based on a multi-source big data fusion platform; secondly, spatial separation of an impervious surface and a water body is achieved through a scanning line seed filling algorithm and geometric feature analysis, and functional types related to cultivated land transformation, offshore cultivation land, a salt pan and reclamation are corrected based on a temporal and spatial change logic rule; and finally, according to a classification result, change ranges and time stages of grain production, offshore culture and reclamation are extracted. According to the invention, the long-time-sequence identification precision of the regional functions of the coastal zone is improved, and the method is particularly suitable for regional function land transformation and change detection of reclamation construction caused by long-time-sequence, large-range and high-density offshore human activities, and can be directly applied to auxiliary decision making of spatial planning and regional policies of the coastal zone.

The invention discloses a method for separating lithium from a salt lake raw bittern. The method comprises the following steps of taking salt lake raw brine as a raw material, contacting the raw material with an adsorption material filled in an adsorption column, and realizing separation of lithium and magnesium, potassium and sodium in the raw brine by an adsorbing process, a liquid ejecting process and a resolving process, and the yield of lithium in the brine is 70%-85%; and obtaining a lithium salt solution by controlling adsorption, liquid ejection and resolving of the feeding flow rate.According to the method, the existing lithium separation process route is shortened, the process of building a large-area salt pan or extracting potassium is avoided, and the loss of lithium in the salt pan beach drying process is reduced, the raw bittern is directly used as a raw material, adsorption materials are used as a basis, simple and practical new process routes of adsorption, liquid ejection and resolving are adopted, lithium separation is achieved in one step, the yield of lithium in the raw bittern is increased to 70%-85% from original 30%-35%, the utilization rate of resources isincreased, and the method is simple and easy to operate and has good application prospects.

The invention discloses a rapid construction method for a seepage-proof dam of a salt pan. The rapid construction method specifically includes firstly, digging a foundation trench; secondly, putting a seepage-proof material to the bottom of the foundation trench, and filling the foundation trench with earth and grinding the earth; thirdly, directly lifting the seepage-proof material to a designed lift height after grinding; finally, earthing up and grinding synchronously on two sides of the seepage-proof material. The construction process includes the steps of foundation trench digging, filming, foundation trench filling, film lifting, earthing-up, grinding, re-earthing-up and re-grinding, and the conventional earth surface construction process, including earthing-up, grinding and film turning, for the seepage-proof dam is changed into earthing-up and grinding, so that process is simplified, construction period is shortened, extruding and folding of the seepage-proof material due to the action of natural angle of repose of the earth during layered and staggered earthling-up and grinding can be avoided, loss of the seepage-proof material is reduced, and construction cost of the seepage-proof dam is saved.

The invention provides a device applied to separation and recovery of carbonate in salt lake water, and belongs to the technical field of compound separation and collection, and the device is characterized in that an ultrafiltration unit is used for filtering a to-be-treated solution containing carbonate to obtain ultrafiltration produced water; the first nanofiltration separation unit is used for obtaining first nanofiltration concentrated water and first nanofiltration produced water; the first reverse osmosis unit is used for treating the first reverse osmosis produced water to obtain first reverse osmosis concentrated water and first reverse osmosis produced water; the second nanofiltration separation unit is used for obtaining secondary nanofiltration concentrated water and secondary nanofiltration produced water; the second reverse osmosis unit is used for primarily concentrating disodium produced water; the concentration unit is used for concentrating the second reverse osmosis concentrated water to obtain a lithium-rich solution; the third nanofiltration separation unit is used for carrying out carbonate separation and concentration on the primary nanofiltration concentrated water; and the salt pan process unit is used for evaporating, concentrating, cooling and crystallizing the Sansodium concentrated water. The carbonate separation and recovery device disclosed by the invention is high in production efficiency, low in cost, recyclable in resource and less in environmental pollution; the pollution of the ultrafiltration membrane and the nanofiltration membrane can be relieved through short-process ultrafiltration, and efficient recycling of salt lake resources is achieved.

The invention relates to the technical field of anti-seepage of solar and airing ponds, and provides an anti-seepage system combining an anti-seepage film with a salt pond plate and a construction method and application thereof. The anti-seepage system sequentially comprises a basic soil layer, the anti-seepage film and the salt pond plate from bottom to top, wherein the salt pond plate is a fixed-salt salt pond plate, and crystal salt in the salt pond plate is sodium chloride. According to the system, traditional anti-seepage film anti-seepage is enhanced to be double anti-seepage of the anti-seepage film and the salt pond plate, the compressive strength of a solar and airing area is improved while the anti-seepage effect is remarkably improved, subsequent mining, maintenance and other production operations are facilitated, meanwhile, due to the fact that the salt pond plate covers the anti-seepage film, the anti-seepage film is not easy to damage, the service life of the anti-seepagefilm can be prolonged, the maintenance cost is reduced, the construction method is simple in steps and easy to carry out, the structure of an original solar and airing pond does not need to be changed, the cost is low, the laying and use of large-area production of salt pans is facilitated, the existing resources can be fully utilized, and the production efficiency is improved.

The invention provides a breeding pond extraction method based on remote sensing time-space spectrum feature fusion, which is characterized by comprising the following steps: 1) performing water body feature and gradient calculation on a remote sensing image scene by scene, and extracting water body and edge features of a single scene; 2) carrying out probability synthesis on the water body and edge features extracted from the scene-by-scene image to obtain initial breeding thematic information; and 3) performing post-processing on the initial breeding thematic information by using the existing terrain, building area and coastline thematic data to obtain a high-precision breeding pond thematic product. The method is mainly characterized in that time sequence features and spectral features and spatial features of remote sensing images are comprehensively utilized, the breeding pond with specific water body features is distinguished from easily-mixed paddy fields, salt pans, rivers and other targets, and therefore high-precision extraction of the breeding pond is achieved.

The invention discloses a salt pan capable of recovering sylvite at low cost and a method for recovering sylvite by adopting the salt pan. The salt pan comprises a crystallizing pond (1) capable of receiving raw brine of the salt pan at the temperature of 45-50 DEG C, a corresponding tail liquid buffer pond (2) is arranged beside the crystallizing pond (1), and a brine conveying channel (3) is arranged between the crystallizing pond (1) and the tail liquid buffer pond (2). The method comprises the following steps: cooling salt pan raw brine input into the crystallizing pond (1) to a specifiedtemperature, crystallizing separated ores, conveying residual tail liquid to the tail liquid buffer pond (2) through a brine conveying channel (3), performing heat exchange preheating on the cooled tail liquid in the tail liquid buffer pond (2) and 85-65 DEG C high-temperature raw brine, heating the preheated tail liquid into a 80-100 DEG C high-temperature solvent through steam, and returning thesolvent to a stope. The salt pan is small in work amount and low in investment, minerals separated out of the salt pan under the natural temperature difference are monocomponent potassium chloride all the time, energy consumption is not needed, energy consumption is low, and the production cost is low.

The invention relates to a salt lake brine filtering method. The method comprises the following steps: (1) conveying salt lake brine exposed to the sun from a salt pan into a first-stage brine filtering system for filtering to obtain first-stage filtered brine; (2) introducing steam into a dilution water heating mechanism in a second-stage brine filtering system so as to heat dilution water, thenblending the heated dilution water and the first-stage filtered brine for diluting, and conveying to a second-stage brine filtering mechanism for filtering so as to obtain second-stage filtered brine;(3) conveying the second-stage filtered brine into a third-stage brine filtering system for filtering to obtain third-stage filtered brine; and (4) conveying the third-stage filtered brine into a fourth-stage brine filtering system for filtering to obtain fourth-stage filtered brine. According to the method, the content of particulate matters such as silt and suspended matters in the salt lake brine is remarkably reduced, and the salt lake brine is prevented from crystallizing at low temperature, so that the purified salt lake brine with relatively low turbidity can be prepared.

The invention relates to a salt lake salt pan anti-seepage agent, which comprises a component A and a component B, wherein the component A is formed by mixing a synthetic copolymer, clay and calcium-containing mineral, the component B is formed by mixing water-soluble silicate and fresh water, and the components specially comprise, by mass, 0.5-1.5% of synthetic copolymer, 10-20% of clay, 12-30% of water-soluble silicate, 8-20% of calcium-containing minerals and the balance of fresh water. The invention further provides a construction method of the anti-seepage agent. According to the invention, the characteristic complementation of all the components is fully utilized, and the seepage-proofing performance is excellent; the adopted raw materials are chemicals with characteristics of easilyavailable source and low price, so that the cost is low; and the preparation and construction method is simple and feasible, is suitable for large-scale engineering, and is especially suitable for seepage prevention of salt lakes and salt pans in Qinghai, Xinjiang, Tibet and other places.

A wind power water stirring vehicle relates to the technical field of power devices and comprises a rope which is horizontally and rotatably arranged, a power blade with a horizontal rotating axis is rotatably mounted at the swing end of the rope, and the blade part below the rotating axis of the power blade is located below the liquid level. The problems that in the prior art, a device can only stir local water areas of a salt pan, water cannot be automatically stirred in a large-range water area of the salt pan, and the salt manufacturing efficiency is reduced are solved.

The invention discloses a lifting type flashboard device, and relates to a lifting type flashboard in the field of salt pan bittern preparing and aquaculture. A cylindrical upper bucket and a cylindrical lower bucket are included. The bottom of the upper bucket is in cup joint to the lower bucket. A seal cover is arranged on the top of the upper bucket. A rubber seal ring is arranged at the bottomof the upper bucket. Two to four water outlets are formed in the side wall of the lower bucket, and the appearances of the water outlets are in an oval or quadrangle-octagon shape. A lifting handle is arranged on the top of the upper bucket and fixedly connected with the upper bucket through a connecting piece. A bittern pipe connector is arranged at the bottom of the lower bucket. The lifting type flashboard device has the beneficial effects that compared with a traditional flashboard, the structure of the lifting type flashboard is changed, flashboard opening and closing are achieved through upper bucket lifting or downward pressing, the structure is simple, the water flow can be effectively controlled, mounting and maintaining are easy, operation is simple and convenient, seal performance is good, and the quality and yield of bittern are improved.

The invention relates to a control device of a distributed salt pan, in particular to an automatic marinating control device and process. The device comprises a flashboard opening device, and a remotecontrol box, a photovoltaic power supply system, a wireless transmission device, a densimeter and a liquid level meter respectively arranged on a flashboard frame. The control method comprises the following steps: performing control operation through the wireless transmission device; opening an outlet gate of the water storage area, and feeding back the state of closing in place to a remote control monitoring room after the flashboard is completely opened; opening a water inlet gate of the water storage area, closing the water inlet gate after the water storage area reaches time, and feedingback a closing-in-place state indication; closing a water outlet gate of an upstream evaporation pool after reaching time, receiving, by the water outlet gate of the upstream evaporation pool, a closing instruction, and stopping an outlet water pump of the upstream evaporation pool in a delayed way after loss of an opening-in-place signal; and starting timing after running of a water inlet pump ofthe upstream evaporation pool, and carrying out closing when running time of the water inlet pump is reached. Compared with the prior art, production operation information can be accurately fed backin time, remote operation and automatic control are achieved, fewer workers are needed and the efficiency is improved.

The invention discloses a mineral recovery method for a carnallite salt pan. The method comprises the following steps: draining a carnallite salt pan until part of the surface of carnallite ores is exposed; gathering carnallite ores by an excavator, forming a fishbone-shaped stacked ore belt in the carnallite salt pan, wherein the stacked ore belt comprises a main road and a plurality of branch roads communicated with the main road, and the widths of the main road and the branch roads are set according to the requirements for moving a transportation tool; excavating carnallite minerals on thetwo sides of the branch roads from far to near with respect to the main road as a reference, making a transport tool for transporting carnallite ores move along the branch roads and the main road; excavating carnallite ores on the two sides of the main road from far to near with respective to the entrance of the main road as the reference, and making a transportation tool for transporting the carnallite ores move along the main road. Carnallite ores are collected through the excavator to form fishbone-shaped stacked ore belts to cover the salt pan bottom plate, a main road and branch roads fora transportation tool to move are provided, the salt pan bottom plate cannot be damaged, and the harvesting is rapid and efficient.

The invention relates to a mechanical device for a salt pan, in particular to an automatic collecting vehicle for clock milk crystal salt for the salt pan. The technical problems that a worker feels tired when working in an area where movement is inconvenient for a long time during collection, and when a salt hanger is used for collection, the salt hanger falls down to hurt the worker are solved. According to the technical scheme, the automatic collecting vehicle for the clock milk crystal salt for the salt pan comprises a moving mechanism, a rack, a lifting mechanism and the like; a rack is connected to the moving mechanism; the right portion of the rack is connected with a lifting mechanism. According to the salt hanger collecting device, manual salt hanger collecting is replaced, the working efficiency is improved, and the problems that during manual collecting, vibration generated by breaking off the salt hanger enables other salt hangers to fall down, workers are stabbed, and meanwhile the salt hangers are broken off are avoided.

The invention discloses a high-efficiency, low-energy-consumption and intelligent bubbling beach drying method and a device, and belongs to the field of evaporation of seawater in the sun to make salt. The device provided by the invention utilizes the increase of the gas-liquid mass transfer area of small liquid drops in bubbles and after the bubbles are ruptured in a bubbling process to accelerate the evaporation rate of seawater. The device provided by the invention is divided into two layers, wherein the upper layer comprises a bubbling pipe array and gas distribution pipes vertical to a plurality of rows of bubbling pipes; and the lower layer comprises a large-caliber gas distribution pipe for enabling gas distribution to be more balanced. The device provided by the invention can improve the salt-drying efficiency of concentrated seawater in coastal areas, has the advantages of low energy consumption, small external influence, small continuous damage to salt pans, high rate of return on beach drying of seawater to make salt, high economic value and strong practicability.

The invention relates to the technical field of salt pan plastic straw mat control, and provides a salt pan photovoltaic rainproof control method, device and system and a storage medium, the salt pan photovoltaic rainproof control method comprises the following steps: obtaining rainwater information of an area where a salt pan is located and a first brine concentration value of the salt pan; according to the rainwater information and a comparison result of the first brine concentration value and a preset value, a rainproof opening command or a rainproof closing command is executed so as to control the rainproof plastic straw mat to shield or open the salt pan; wherein the preset value is a standard brine concentration value set for ensuring the yield of the salt pan. Whether the rainproof plastic straw mat needs to be automatically unfolded to shield the salt pan or automatically folded to open the salt pan can be more reasonably and accurately judged, water evaporation of the salt pan is prevented from being affected, the brine concentration of the salt pan is adjusted by controlling the evaporation capacity of the salt pan, and therefore the salt yield of the salt pan is increased.

The invention discloses edible salt refining production equipment which comprises a box body, an inner cavity is formed in the box body, symmetrical connecting sliding grooves are formed in the end wall of the inner cavity in a communicating mode, a loading inner cavity is formed in the box body, and a containing cavity is formed in one side of the loading inner cavity in a communicating mode. A penetrating hole is formed between the containing cavity and the connecting sliding groove in a communicating mode, an ejection air cylinder is arranged in the lower end wall of the loading inner cavity, an ejection plate is arranged in the loading inner cavity in a sliding mode, the ejection plate is fixedly connected with a push rod of the ejection air cylinder in a matched mode, and a side push air cylinder is arranged on one side of the box body. The equipment can effectively shield the salt pan in severe weather in the process of producing edible salt in the open-air salt pan so that the salt pan dried in the sun is prevented from being wetted again.

The invention belongs to the field of salty mud curing, and particularly relates to a salty mud curing material as well as a preparation method and application thereof. The salty mud curing material provided by the invention is prepared from salty mud, solid particles, aluminum-containing mineral clinker and a water reducing agent. According to the invention, a large amount of salty mud solid waste can be consumed, effective adsorption and fixation of chloride ions are controlled by combining inherent components in the salty mud and skillfully utilizing the theory of nascent hydrotalcite, the precipitation of the chloride ions is controlled, and high strength and high surface performance of the curing material are realized; therefore, the method is applied to construction of a salt pan slope protection and a salt pan road, and the actual requirements of field pressure resistance, sun resistance, impact resistance and the like can be met.

The invention discloses a construction method for a salt pan isolation dam. The method comprises the following steps that the ground surface of an area where the salt pan isolation dam is to be constructed is tamped, and brine is sprayed to form a ground surface layer; a first mixture is laid on the ground surface layer to a first set height to form a base layer; a second mixture is laid on the base layer to a second set height to form a surface hardening layer, and the ground surface layer, the base layer and the surface hardening layer form a main body; and magnesium chloride crystals are laid on the side slope of the main body from top to bottom, tamping is conducted after the brine is sprayed, a magnesium chloride layer is formed, and the salt pan isolation dam is obtained. According to the provided salt pan isolation dam, the base layer is laid through the first mixture formed by mixing saline soil and waste salt, so that local materials are used, and the transportation period isshortened; the surface hardening layer is laid through the second mixture of waste salt and magnesium chloride, so that enough strength can be provided, and the surface hardening layer is not prone toweathering or brine scouring; and the magnesium chloride layer is used for protecting the main body from being washed away by brine in the salt pan and preventing the isolation dam from being damagedand the salt pan brine turbidity from increasing.

The invention relates to the technical field of edible salt extraction, in particular to nutritional type green edible salt extracted from salt lake mining areas and an extraction method thereof. The method specifically comprises the steps of salt pan production, a test for removing trace heavy metals in a solid sample, a test for improving the dissolution rate of the solid sample and a test for changing components of the edible salt solid sample. According to the method, in the salt pan sampling and washing work, used equipment is light and handy, and the operation is relatively simple; physical washing is adopted and does not pollute brine in the salt pan, and washing tail liquid is discharged into the salt pan and does not affect carnallite production in the salt pan; the whiteness, granularity, sodium chloride, water-insoluble substances, lead, arsenic, fluorine, barium and other related hygienic and chemical indexes after washing completely meet the national edible salt standard; trace heavy metals in the solid sample are further reduced by an alkali washing method; the solid sample can be dissolved within about 6 seconds at the fastest rate; and in addition, operations such as road construction, drilling, groove exploration, pit exploration, well exploration and the like which damage the soil surface do not exist in the test process.

The invention relates to the salt pan plastic straw mat control device technology field and especially relates to a salt pan straw mat cover intelligent control system and method based on an environment Internet of things. The salt pan straw mat cover intelligent control system based on the environment Internet of things comprises straw mat cover equipment, an intelligent control module and a saltpan microclimate monitoring station. The intelligent control module is in communication connection with the straw mat cover equipment and the salt pan microclimate monitoring station. And the straw mat cover equipment unfolds or folds a plastic tarpaulin according to a control instruction sent by the intelligent control module. By using the salt pan straw mat cover intelligent control system based on the environment Internet of things, the salt pan microclimate monitoring station is arranged in a salt pan, weather change information of an area where the salt pan is located is monitored in real time to obtain weather change prediction information of the area where the salt pan is located; and the intelligent control module automatically judges an opportunity of folding and unfolding a straw mat cover and makes the straw mat cover equipment unfold or fold straw mat cover cloth according to the weather change prediction information of the area where the salt pan is located so that automatic folding and unfolding of the salt pan straw mat cover are achieved.

The invention discloses an injection device for correcting reverse rotation of a hanging head, and belongs to the field of salt pan covering tools. A turnover brush and a driving device for driving the turnover brush are arranged on the basis of an existing injection device assembly. By arranging the turnover brush on a front end plate, a hanging head, facing the inner side of a plastic carpet, ofthe plastic carpet in the advancing process is turned over to face the outer side. The efficiency of the plastic carpet in the covering process is greatly improved by the injection device, the laborcost is reduced, and the loss of the salt pan caused by raining is reduced.

The invention relates to a collecting device, in particular to a push shovel-type salt pan sea salt collecting device. According to the push shovel-type salt pan sea salt collecting device, the laborintensity of workers can be reduced, and the working efficiency of the workers is improved. The push shovel-type salt pan sea salt collecting device comprises a shell, a first rotating rod and the like; and the first rotating rod is rotationally arranged at the lower part of the rear side of the shell. The device can be driven to move through a driving assembly; a collecting assembly can be drivento work; workers control the device movement, the sea salt is pushed to the edge of the salt pan through a scraper; a control assembly enables the driving assembly to drive the collecting assembly tocollect the sea salt; therefore, sea salt can be collected, the device is driven by the motor to operate, the labor intensity of workers can be reduced, the working efficiency of the workers is improved, part of seawater mixed with the sea salt can be removed during sea salt collection through the arrangement of a guide rod, a gauze element and a water outlet, and therefore the air drying time ofthe sea salt can be shortened.

The invention relates to the technical field of seawater salt pan salt making and especially relates to a salt pan accurate tide receiving system and an accurate tide receiving method based on an environment Internet of things technology. The system comprises a tide receiving reinforcing dam, a tide receiving gate, sub-runners and buoy concentration detection equipment. The tide receiving gate isarranged at a tide receiving port of the tide receiving reinforcing dam. A tide receiving sea area is divided into a plurality of tide receiving areas by the several sub-runners which take the tide receiving port as an original point. The plurality of buoy concentration detection equipment is arranged in the tide receiving area. The buoy concentration detection equipment transmits a detected seawater concentration to a tide receiving control system, and the tide receiving control system controls an opening and closing state of the tide receiving gate according to a seawater concentration. By using a technical scheme of the invention, seawater salinity in the tide receiving area and the surrounding area is monitored in real time through the environment Internet of things technology, and a tide receiving opportunity and a tide receiving range of salt pan production are determined to a great extent so that an initial concentration of tide receiving of a salt pan is increased, salt pan production efficiency is greatly improved, and the method plays an important role in actual production of the salt pan.

The invention belongs to the field of marine shellfish cultivation, and in particular relates to a large-scale cultivation method for preventing and controlling the invasion of alien marine shellfish organisms. The method comprises steps such as selection of tidal flat ponds and pond design, preparation before putting seedlings, stocking of seedlings, management of growth period, feeding management, disease prevention and control, growth detection, management of hard shell clams in overwintering period, and harvesting. Utilizing the tidal flat breeding area of ​​coastal salt fields in my country, using the polyculture of clams and prawns, the ecological conditions of the prawn farming ponds are improved, and the benefits of pond farming are improved; the risk of breeding is reduced, and the salinity is used for reproductive ecological isolation, blocking shellfish The way for larvae to flow to the sea and isolate the way for biological invasion.

The invention provides a coast culture pond extraction method based on spatial similarity and a corrected salt pan index, and the method comprises the steps: obtaining Landsat-8 image data, and carrying out preprocessing of the Landsat-8 image data; performing strip-shaped water body positioning on the preprocessed image so as to obtain coastal zone water body image data, and extracting crystallizing pond area image data of a salt pan based on spectral difference of a crystallizing pond and a culture pond and strip-shaped texture features of the crystallizing pond; extracting reservoir area image data based on spatial distribution features of a reservoir and the crystallizing pond; and removing the crystallizing pond area image data and the reservoir area image data from the coastal zone water body image data so as to obtain culture pond area image information. According to the method, the salt pan-containing coastal zone culture pond of a multispectral image under the medium resolution can be effectively extracted.

The invention relates to the technical field of salt pan slag breaking treatment, in particular to a salt pan slag breaking method which comprises the steps: positioning four-corner coordinates of thesalt pan; planning a walking route of the slag breaking device according to the information of the four positioning points; and a slag breaking device carries out slag breaking treatment according tothe planned walking route. The slag breaking route is planned, repeated slag breaking and slag breaking omission are effectively avoided, and thus the working efficiency is improved.