13031results about How to "No pollution in the process" patented technology

The invention discloses a method for preparing diethyl oxalate by CO coupling reaction. By applying a gas phase method, CO is coordinated with ethyl nitrite and is catalyzed by bimetallic supported catalyzer to couplingly generate crude diethyl oxalate, the reaction is a self-sealing circulation process, the CO gas mixed with the ethyl nitrite coming from a regeneration reactor is preheated and then enters into a coupling reactor, after the reaction, the gas is separated by condensation, so that the colorless and transparent condensed diethyl oxalate liquid is produced, and the uncondensed gas containing NO enters into the regeneration reactor to react with ethanol and oxygen in order to generate ethyl nitrite which is again circulated back to the coupling reactor for continuous use. The invention is carried out on the basis of previous laboratory research and under the background of industrial production and fulfils the continuous run examination of the bench scale test and pilot magnification under the condition of industrial operation, the temperature of the coupling reaction is low, and the concentration of products is increased. The method has the advantages of more energy saving, no pollution and high benefit. The total conversion rate of the CO generated by reaction is one hundred percent, and the selectivity of diethyl oxalate is over ninety six percent.

The invention discloses a particle-typed composite fertilizer of humic acid and manufacturing method, which consists of dressing and karyosome, wherein the dressing contains nitrogen, phosphor and potassium. The manufacturing method comprises the following steps: graining humic acid; cladding; graining; solidifying fused fertilizer on the particle of humic acid; making the composite fertilizer dissolved into water without falling; fitting for large scale of agricultural product.

The invention discloses a method to synthesize propylene oxide, which is characterized in that alcohol with low content of carbon, propylene and oxydol(mol ratio 1-15:0.5-5:1) are put into a reactor which is fed with catalyzer; the propylene and the oxydol react and produce propylene oxide, and the condition for the reaction includes: temperature 30-90 DEG C, pressure 0.5-4.5MPa, ph value of the solution 5,0-8.0, and airspeed of the solution 0.1-7h-1; wherein the temperature and ph value of the solution in the whole process are adjusted according to the conversion rate of the oxydol, and once the conversion rate of the oxydol drops to 88.5%, the ph value and the temperature of the solution are increased. The method is simple in process, mild in condition, the conversion rate of the oxydol is high and the propylene oxide is of selectivity; meanwhile, the life of the catalyzer is prolonged to over 1200h through the adjustment of the ph value and the temperature of the solution.

The present invention provides a preparation method of (S)-4-hydroxyl-2-oxo-1-pyrrolidine acetamide. The preparation method comprises: (S)-4-halogen-3-hydroxyl butyric ester as a raw material reacts under the conditions with polar solvent and alkalinity to prepare the crude product of (S)-4-hydroxyl-2-oxo-1-pyrrolidine acetamide; and the crude product is purified. The preparation method is characterized in that inorganic alkali is added for a plurality of times in the reaction process under the condition with alkalinity so as to control the pH value in the reaction to be less than or equal to 8.5. A large quantity of repeated tests are completed to determine that the optimum pH value of the reaction under the condition with alkalinity is less than or equal to 8.5, and the alkali is added in batches to strictly control the pH value of the whole reaction process, so that the alkali conditions required in the reaction can be satisfied and the reaction can be performed completely, and the target product (S)-oxiracetam is prevented from being damaged in the alkaline solution, thereby improving the yield rate of the target product (S)-oxiracetam and reducing the cost.

The invention discloses a method for recovering and preparing lithium iron phosphate from waste lithium iron phosphate batteries. The method comprises: 1) dismantling the recovered waste lithium iron phosphate batteries, stripping battery cases, immersing the batteries, separating the electrode plates from the powder material of positive and negative terminals through a method of alternation of ultrasonic and mechanical stirring, taking out the electrode plates and diaphragms, and obtaining mixed liquor; 2) performing a preliminary ball milling to the mixed liquor, and drying the uniformly mixed slurry obtained by the preliminary ball milling; 3) calcining the dried material in oxidizing atmosphere to obtain a recovered material, adding iron source, phosphorous source and optionally new lithium iron phosphate, then adding carbon source, high energy ball milling the obtained material, drying the material to obtain a pre-burning material of the recovered material; 4) microwave sintering or solid state sintering the pre-burning material of the recovered material in protective atmosphere to obtain the product of lithium iron phosphate. The preparation method has the advantages of environmental protection, no pollution, simpleness and practicality, high production utilization rate, simple

The invention discloses a preparation method of a graphene/polymer nano composite material, which is characterized by comprising the following steps: adding 0.1-30 parts by weight of graphite oxide into 10-3000 parts by weight of water, and dispersing and exfoliating by carrying out ultrasonic dispersion (the power is 50-500W, and the frequency is 10-100000Hz) at 10-100 DEG C for 15 minutes-5 hours or mechanical lapping for 15 minutes-5 hours or mechanical stirring for 1-48 hours to obtain a graphene oxide water solution; adding the graphene oxide water solution into 100 parts by weight of polymer emulsion of which the solid content is 10-70%; continuing the ultrasonic or mechanical stirring to carry out uniform mixing; demulsifying by adding 1-100 parts by weight of 5-100% demulsifier toobtain a graphene oxide/polymer granular suspension; adding 0.1-100 parts by weight of reducer into the graphene oxide/polymer granular suspension, reducing at 20-100 DEG C for 1-72 hours, filtering,and drying in a drying oven at 20-100 DEG C for 2-72 hours or drying in a vacuum drying oven at 20-120 DEG C under a vacuum degree of 0.1-0.01 MPa for 2-48 hours, thereby obtaining the graphene/polymer nano composite material.

A full nutrition fertilizer of biology type and its producing method belongs to organic complex fertilizer field in biology type. The components of the full nutrition fertilizer is 20-50% of organic waste liquid, 10-30% of urea, 8-15% of diammomium phosphate, 10-25% of potassium sulfate, 5-20% of medium trace element, 1-5% of microbial inoculum, 0-0.2% of root-promoting agent; 0-2% of solutizer, effective viable count content of the microbial inoculum of more than 1010/g. The fertilizer is produced by adding the urea, diammomium phosphate, potassium sulfate, medium trace element, root-promoting agent, solutizer into organic waste liquid and blending uniformly, then adding microbial inoculum. The invention uses the wastes to produce fertilizer with a low cost a high availability and a good prospect in the fertilizer industry. The fertilizer can be widely applied to the vegetables, melon and fruits, food, tobacco, forests and different commercial crops.

The invention discloses a method for preparing monopotassium phosphate by using wet-process phosphoric acid. The method comprises the following steps: reacting carbonyl diamide and wet-process phosphoric acid to obtain an intermediate; reacting the intermediate and potassium hydroxide to prepare a monopotassium phosphate product. The method has the advantages of short process route, low energy consumption, stable product quality, low production cost, convenience in operation and safety in production. A side product, namely, slurry can be recycled completely, an entire production process is environment-friendly, clean and free from pollution, and no waste gas, waste water or waste residues are discharged. A response is made to the policy calling of energy saving, emission reduction and clean production, the problems of complex process, instable product quality, high energy consumption and environmental pollution existing in the prior art are solved, and the purity of the obtained monopotassium phosphate product is more than or equal to 98 percent.

Disclosed is a method for soft soil foundation treatment through microorganism grouting sand drain. The method comprises the steps that a, a pile hole 1 is formed in a soft soil foundation to be treated, and sand is poured into the pile hole 1 to form a sand pile; b, a urease-producing microorganism solution 9 and a nutritive salt solution 10 are sequentially and evenly injected into the sand pile through a grouting tube 6, sand cementation is achieved through the microorganism induction calcium carbonate crystal technology, the concentration of the urease-producing microorganism solution 9 and the concentration of the nutritive salt solution 10 are controlled, sand in the pile body forms a specific cementation mode, and the good water permeable characteristic is ensured; c, after the microorganism grouting solidification sand pile is formed, a flexible water permeable sand cushion 4 is laid on the top of the foundation jointly formed by the sand oil and pile space soil 2, prepressing loads 5 are exerted on the top of the flexible water permeable sand cushion 4, pore water in the pile space soil 2 is made to be drained along a drainage channel formed by the sand pile and the sand cushion, the pile space soil is solidified, and the composite foundation with the high bearing capacity is formed jointly through the soft soil obtained after drainage and solidification are carried out on the microorganism grouting sand pile and the flexible water permeable sand cushion covering the soft soil.

The invention discloses a normal-temperature synthesis method for a polycarboxylic acid water-reducing agent, and belongs to the field of cement concrete water-reducing agents. The water-reducing agent is prepared by the following steps of: copolymerizing polyoxyethylene ether monomer or polyoxyethylene ester monomer a containing unsaturated double bonds, unsaturated monocarboxylic acid and derivative monomer thereof b, unsaturated dicarboxylic acid c and unsaturated sulfonic acid or salt monomer thereof d in aqueous solution under the action of an oxidation reduction initiator, and finally neutralizing the solution by using alkali solution to obtain the water-reducing agent. The reaction can be performed at room temperature by adopting an oxidation reduction initiating system, and the appropriate reaction temperature is between 5 and 30 DEG C; and the synthesis process does not need heating, so energy is saved, and high-temperature side reaction is effectively controlled. The prepared polycarboxylic acid high-performance water-reducing agent has the characteristics of high water-reducing rate and good collapse protecting performance. The water-reducing agent has wide application range, and the method has low production process requirement and is suitable for industrialized large-scale production.

The invention discloses a method for preparing a manganese series lithium ion sieve adsorbent, and relates to a method for preparing an inorganic adsorbent for adsorbing lithium from liquid lithium resources such as brine of salt lake, seawater and the like. In the method, a cubic crystal ion sieve precursor Li1.6Mn1.6O4 is prepared from Mn2O3 and LiOH or Li2CO3 serving as raw materials by using two sections of solid-phase reactions, wherein the precursor also can be used as an anode material of a lithium ion battery. The precursor is acidized to obtain a lithium ion sieve adsorbent MnO2.0.5H2O (or expressed as H1.6Mn1.6O4), and the ion sieve is the lithium adsorbent which has high selectivity on lithium. The method has the advantages of simple and readily available raw materials, simple process, high adsorption capacity of the ion sieve, low cost, high purity of products and is easy to realize industrial production.

The invention belongs to the field of material science and particularly relates to a graphene oxide/cellulose compound material as well as a preparation method and application of the material. The compound material is prepared by mixing graphene oxide suspension and alkaline solution of cellulose, and forming a compound structure of the graphene oxide and the cellulose under the action of mechanical stirring, shearing, ultrasonic or the like. In the preparation method, raw materials are cheap and easy to obtain, a water system is simple and free of pollution, equipment is simple and low in cost, and the industrial preparation is easy to realize; and the prepared compound material has the properties of fiber and the graphene oxide and is widely applied.

The invention relates to an electrothermal film and a manufacturing method thereof, belonging to the technical field of semiconductor heating. The electrothermal film is mainly prepared by adopting stannic chloride, titanium tetrachloride, stannic chloride, titanium trichloride, ferric chloride, antimony trichloride, calcium chloride, potassium chloride, cadmium chloride, stannic dioxide, stannictetroxide, hydrofluoric acid, boric acid, ethanol, isopropyl alcohol and inorganic water. By adopting the above formula, the mixture is mixed, stirred and heated to prepare into electrothermal film treating fluid, a semi-finished product of the electrothermal film is obtained by spraying the electrothermal film treating fluid at negative pressure on the electrothermal film carrier, and then silveroxide slurry is coated on the semi-finished product of the electrothermal film for baking to form a finished product of the electrothermal film. The electrothermal film has reasonable proportion andsimple manufacturing process, can be manufactured into various electrothermal film heating devices, has a working temperature capable of being up to 500 DEG C, and has wider application range. The electrothermal film of the invention also has the function of far infrared radiation, can play a role of physical therapy and health care to human body, and can help improve the quality and output of agricultural products.

The raw material composition of the invented high-concentration aqueous film-forming foam extinguishing agent includes fluorocarbon surfactant, hydrocarbon surfactant, organo-silicon surfactant, stabilizing coupler, chelating agent, spreading burn-resisting agent, bacteriostatic agent and water. It can be used for quickly extinguishing oil fire.

The invention relates to a method for preparing tobacco extract and application thereof. The method for preparing the tobacco extract uses tobacco as a raw material to prepare the tobacco extract through the steps of enzymolysis, ultrasonic extraction, filtration, chromatography column separation and concentration under reduced pressure; and the tobacco extract is dissolved by 80 percent ethanol and sprayed into tobacco shreds by adopting an atomizing mode. The method using enzymolysis technology and ultrasonic extraction and combining the chromatography separation has the advantages of low extraction temperature, short time, little using amount of a solvent, full extraction and high raw material utilization rate; because the extraction temperature is low, the damage to thermal-sensitive fragrant substances is reduced, fragrant components of the tobacco self is furthest kept, and simultaneously the substances influencing the taste and mouthfeel are removed; and the method is simple, the equipment is easy to operate, and no pollution is produced.

The invention provides a control method and a control device used for micro-satellite cluster flying based on atmosphere resistance, and relates to the technical field of micro-aircraft and astronautics measuring and controlling. The signal output terminal of a GPS receiver is connected with the signal input terminal of a track determining device; the signal output terminals of a solar battery array and a three-axis magnetometer are connected with the input terminal of an attitude fusion filter; the output terminal of the three-axis magnetometer is connected with the input terminal of a pure magnetic measuring attitude fusion filter; the signal output terminal of the attitude fusion filter is connected with the second input terminal of a satellite line; the first output terminal of the satellite chain is connected with the input terminal of a cluster formation control law; the second output terminal of the satellite chain is connected with the input terminal of the satellite attitude control law; the formation and attitude of the satellite cluster flying are controlled by controlling a pneumatic plate. The method and the device achieve the objects of long service life of the aircraft, low power dissipation, low cost and no pollution on the basis of atmosphere resistance.

The invention relates to a phosphorus-free metal cleaning agent comprising the components of, by weight, 2-20% of a cleaning aid, 1-20% of a surfactant, 1-10% of a chelating agent, 1-20% of an emulsifier, 1-10% of an antirust agent, 0.2-4% of a copper alloy corrosion inhibitor, 1-10% of a penetration agent, 1-6% of a solubilizing agent, 0.1-0.6% of a defoaming agent, and balance of water. The cleaning agent provided by the invention has excellent cleaning capacity, long rust proof period, low foam, long service life, and the like. The cleaning agent is suitable for ferrous metal and non-ferrous metal processing industries. The agent has the advantages of no volatilization, no irritation, no toxic or harmful substance such as nitrite, no damage to health, and no environment pollution.

The invention discloses a process method for preparing an ultra-hydrophobic surface by the electrochemical method. The process adopts two processing steps: forming the micro nanometer double-structurerough surface by first electrochemical etching and then oxalic acid anodic oxidation; and preparing the ultra-hydrophobic surface by modifying the surface with fluorosilane. The method is simple andpractical, uses mature electrochemical etching and anodic oxidation technology, allows for easy mass production and avoids environmental pollution.

The invention discloses a method for separating and recovering lithium from a waste lithium ion battery. The method comprises the following steps: dismounting after discharging the waste lithium ion battery, and removing a battery case; crashing a battery cell; leaching and filtering the crushed battery cell with inorganic acid and oxidant to obtain a filter liquor; regulating the pH of the filter liquor to be more than or equal to 8, then filtering to remove impurities and sediment to obtain a recovery liquor containing lithium ions; adsorbing the lithium ions in the recovery liquor through resin; and desorbing the resin to obtain the separated and recovered lithium salt. The recovery method provided by the invention is simple and efficient, has high purity of lithium and brings no pollution.

The invention relates to porous concrete and a preparation method thereof, in particular to novel nano porous concrete which is prepared by taking thixotropic colloid as a template agent to form a uniform-water-phase three-dimensional network nano porous structure and adding cementing materials, fine aggregate, coarse aggregate, an admixture and an additive. The nano porous concrete has the characteristics of being light, high in strength and low in heat conductivity, can be prefabricated into bricks, building blocks, plates, and assembly type stairs, wallboards, balcony slabs and roof panel parts in a factory, can be also cast on a construction site, and further can be prepared into mortar, thereby having remarkable practical significance on promotion of development of housing industrialization and green building concrete material in our country.

The invention discloses low-cost green cellulose aerogel and a preparation method for hybrid aerogel thereof. The preparation method for the hybrid aerogel of the cellulose aerogel comprises the following steps that cellulose is dissolved into a zinc chloride aqueous solution, centrifugal deaeration is performed, and a uniform and transparent cellulose solution is obtained; the cellulose solution is formed, then the formed cellulose solution is placed into a coagulating bath to be regenerated, in addition, the regenerated cellulose solution is fully washed by use of a solvent, and cellulose solvent gel is obtained; the solvent in the cellulose solvent gel is removed by use of supercritical carbon dioxide drying or freeze drying, and the cellulose aerogel is obtained. Functional filler can be added into the cellulose solution to obtain the hybrid aerogel. By the adoption of different solution forming methods, the cellulose aerogel and the hybrid aerogel thereof in the shapes of sheets, fibers, particles and the like can be prepared. The preparation method is low in cost and is environmentally friendly, and the prepared aerogel is provided with a uniform nano-grade net porous structure.

The invention relates to a preparation method of a star polycarboxylic acid high-performance water reducing agent. Polybasic alcohol and (methyl) acrylic acid used as main raw materials for esterification are esterified and polymerized to prepare the star polycarboxylic acid high-performance water reducing agent material: the (methyl) acrylic acid and polybasic alcohol used as reactants are esterified under the action of a catalyst to firstly prepare a star polymerizable active terminal, and free-radical polymerization reaction is carried out with unsaturated polyethenoxy ether, molecular weight regulator and unsaturated carboxylic acid monomer under the action of an initiator to prepare the star polycarboxylic acid high-performance water reducing agent. The invention is easy to control, and has the advantages of high polymerization degree, low cost and no pollution; the esterification reaction is carried out form an active core, and the free-radical polymerization is carried out to generate the chain arm, thereby implementing the polycarboxylic acid high-performance water reducing agent in a star molecular structure; and under the condition of common doping amount and low doping amount, the star polycarboxylic acid high-performance water reducing agent has better cement paste flowability and holding capacity than the traditional linear and comb polycarboxylic acid water reducing agents, and has favorable cement adaptability and concrete application performance.

The invention relates to hydrocracking of lignin, and specifically relates to a method for applying a tungsten-based catalyst to catalyze lignin hydrocracking for producing an aromatic compound. The catalyst comprises a main active component of non-zero-valent tungsten, and a second metal component of a small amount of one or more transition metals selected from zero-valent nickel, cobalt, ruthenium, iridium, palladium, platinum, iron, and copper. According to the method, raw materials such as lignin, biomass hydrolysis residue, lignosulfonate, and alkaline lignin are subject to catalytic hydrogenation under a hydrothermal condition with a temperature of 120 to 450 DEG C and a hydrogen pressure of 1 to 20MPa; the raw materials are cracked into C6-C9 phenolic compounds with high selectivity. A maximal phenol yield reaches 55.6%. Compared to existing technologies, according to the invention, renewable natural biomasses are adopted as raw materials, such that the raw materials are cheap, and have wide sources; inorganic acid and alkali are not required, such the production of a large amount of alkaline solution in traditional lignin catalysis is avoided; the tungsten-based catalyst is cheap; the reaction process is green, and has atom economical characteristics.

The invention provides a Chinese medicine residue organic fertilizer. Wastes after extraction of Chinese traditional medicines can be fully utilized, utilization of waste materials is realized, and a bactericidal and insect disease preventing organic fertilizer full of nutritional ingredients is also provided for agricultural production. The Chinese medicine residue organic fertilizer is prepared by fermenting Chinese medicine residue, excrement of animals, solid waste, bacillus subtilis and EM. The Chinese medicine residue organic fertilizer has the advantages that the Chinese medicine residue, excrement of animals and solid waste are mixed, biological fermentation bacteria are added for carrying out rapid fermentation, organic fertilizer is processed, waste materials are changed into things of value, harm is turned into good, the problem of treatment of abandoned herb residue produced by a Chinese medicine factory is solved, and waste treatment cost is also greatly reduced, so that a win-win situation of environmental protection and economic development is realized. By adopting the organic fertilizer made from the Chinese medicine residue, soil can be effectively improved, crop pest also can be effectively prevented, and quality, yield and safety of crops are improved.

The present invention belongs to extraction of nonferrous metal, and it is a method for deep removing impurities of elements of K, Mo, Fe, Co, Ni and Cu, etc. from manganese sulfate solution. It is characterized by that the precipitant or reagent can be added into the manganese sulfate solution to form precipitating agent in the solution to remove the impurities from solution. The EMD extracted by said method not only can meet the requirements for producing functional cell, but also its process is simple and cost is low.

The invention discloses a preparation method for a mixture of a polymer and graphene. The advantage that graphite powder and the polymer are both granular powder is utilized, a graphite layer is stripped in situ according to a dry ball milling method, and the mixture of polymer and grapheme is prepared. The preparation method particularly comprises the following steps: (1) premixing the graphite powder and the polymer; (2) conducting ball milling and stripping on the pre-mixture fully in a ball mill to prepare the mixture of the graphite powder and the polymer. The preparation method adopts the dry ball milling method, so problems in solvent recovery and pollution caused by methods of solution mixing, in situ polymerization, wet ball milling, and the like are avoided; meanwhile, the defect of uneven dispersion of the graphene during fusing and dispersing process is overcome, the technological operation is simplified, and promotion and use are facilitated; the mixture of the polymer and the graphene is suitable for polymer processing methods of extrusion, injection molding, mould pressing, blow molding, curtain coating, and the like.

The invention relates to a detergent for daily use, and specifically relates to an environment-friendly type hyperconcentration biological enzyme liquid laundry detergent and a preparation method thereof. The prepared product in the invention is mobile liquid with low viscosity, contains no phosphates, fluorescent brightening agents or alkylphenol polyoxyethylene, and has no pollution to environment. The production process for the product is simple; preparation and mass production of the product are easy; the product can be widely used for washing of various fabrics and clothing and is both applicable to hand wash and machine wash. The environment-friendly type hyperconcentration biological enzyme liquid laundry detergent comprises, by weight, 0.5 to 50 parts of fatty alcohol polyoxyethylene ether sodium sulfate-70, 0.5 to 50 parts of fatty alcohol polyoxyethylene ether-9, 0.5 to 30 parts of sodium alkylbenzene sulfonate-60, 0.2 to 15 parts of triethanolamine, 0.1 to 10 parts of sodium citrate, 0 to 5 parts of citric acid, 0 to 5 parts of aliphatic acid, 0.02 to 8 parts of biological enzyme, 0.1 to 20 parts of an enzyme stabilizer, 0.5 to 30 parts of a solvent, 0 to 15 parts of a hydrotropic agent, 0 to 5 parts of a bactericide, 0.001 to 5 parts of an antiseptic, 0 to 3 parts of essence and 1.0 to 40 parts of softened water.

A nano-class mesoporous Ag-carried antibacterial agent used for detergent, cosmetics, water treating, textile, etc contains inorganic oxide as carrier with orderly mesopore structure and Ag as active antibacterial component. Its advantages are large specific surface area, broad spectrum, high effect and durability, and no damage to people.

The invention discloses a preparing method of graft copolymerization carboxylate high-performance dehydragent belonging to dehydragent domain, which comprises the following steps: choosing methoxy carbowax with molecular weight distributing between 1000-2000 and acroleic acid or methacrylic acid as main raw material; adopting total acid method esterified priority method; preparing intermediate (big monomer) with polymerization activity; adding third monomer into polymerization reaction; adjusting polymerization activity of copolymerization system; proceeding technique route synthesis of main chain polymerization in the water solution. The getting big monomer possesses merits of high conversion rate, short reacting time, simple process flow and strong controlling property.

The invention discloses a plugging flexibilizer, comprising the components in parts by weight: 5-12 parts of polypropylene fiber, 20-30 parts of rubber particles, 1-5 parts of high molecular polyacrylamide, 2-8 parts of toughened nylon, 2-8 parts of asbestos section, 5-12 parts of plant fibers, 4-7 parts of calcium hydroxide, and 0.1-0.4 part of polyanionic cellulose PAC-HV. A preparation method of the plugging flexibilizer comprises the following steps: orderly adding the components in parts by weight to a kneading machine according to a conventional preparation method at constant temperature and constant pressure; evenly mixing and stirring; and crushing into a 0.05-1mm granular product. The plugging flexibilizer has the characteristics of being wide in material source, free of toxicity and pollution, simple and convenient in construction technology, good in rheological property, good in pillar-forming property, strong in tenacity, not easy to fragilely fall off, high in plugging success rate and the like, does not easily generate a rupture and a brittle fracture in the drilling process after plugging, and is widely applied to pressure-loaded plugging engineering of low-pressure fractured formation, large cracks, large caves, subterranean rivers and serious voidage formation in petroleum and geological drilling.