Abstract: A turbocharged internal combustion engine having an engine control unit and apparatus coupled to the turbocharger, to assist in acceleration of the turbocharger in response to an acceleration signal from the engine control system and to decelerate the turbocharger in response a deceleration signal from the engine control unit. The apparatus absorbs energy from the turbocharger in response to the deceleration signal from the engine control unit to decelerate the turbocharger. The apparatus includes one or more hydraulic wheels on the same shaft of, and between, the turbine and compressor of the turbocharger, the one or more hydraulic wheels being driven in response to the acceleration signal to assist in acceleration of the turbocharger or absorb energy from the turbocharger shaft in response the deceleration signal.

Abstract: The present techniques provide methods and systems for producing geothermal energy. The techniques include extracting geothermal energy from regions in a reservoir so as to reduce the stress in proximate regions. The geothermal energy is extracted from the proximate regions, and the extraction of geothermal energy is staged across subsequent regions in the reservoir.

Abstract: A steam seal dump re-entry system delivers steam dump flow to an LP steam turbine. The system includes a steam seal header receiving steam leaking from turbine end seal packings, and a desuperheater receiving and cooling the steam from the steam seal header. The desuperheater outputs cooled steam. A temperature sensor is disposed downstream of the desuperheater and detects a temperature of the cooled steam. A flow control circuit communicating with the temperature sensor selectively delivers the cooled steam to at least one of the condenser and to the LP steam turbine depending on the temperature of the cooled steam.

Abstract: The air cooling system and method for a heat recovery steam generator (HRSG) inlet provides a combined cycle power plant utilizing a powerful fan coupled to ductwork connected to pipes that enter the HRSG inlet duct coupled to an exhaust duct of a Combustion Turbine (CT) for lowering the temperature of the CT exhaust gas provided to the heat recovery steam generator by the CT. The cool air injection system is utilized during low load operation or startup of the CT to ensure that spray water from an inter-stage desuperheater in an HRSG is fully evaporated prior to entering the downstream superheater or reheater. A feedback system includes temperature elements measuring the mix temperature that regulates the cooling air injection rate into the HRSG inlet.

Abstract: Systems and methods of integrating plasma waste processing are described. An integrated energy generation system provided with a fossil fuel power plant system having a combustion chamber and a plasma waste processing system having an output. The integrated energy generation system also including an integrator for combining the output of thermal energy from the plasma waste processing system with the combustion chamber of the fossil fuel power plant.

Abstract: This system, consists of mainly two parts which are power production apparatus by moment of inertia principle and closed compressor system. The apparatus converts the linear force applied on it or rotational motion to oscillation motion and transfers it to massive element (10). This massive element (10) converts the moment of inertia force created by skidding action with two-centered motion to rotational motion. The accelerated compressor of the apparatus with the oscillation motion of hammer element (2) uses the pressure of compressed air in its chamber (27) and acts as a machine of two cylinder. This continuous oscillation motion thus created with this system is converted to rotational motion by this apparatus. This system can be used in all kinds of system which produce work and energy.

Abstract: An optical fiber crack detector that includes a plurality of FBG sensors positioned within one or more fibers that are operable to reflect a defined wavelength of an optical input beam. The crack detector includes a light source for generating the optical input beam that propagates down the optical fiber and interacts with the FBG sensors. A wavelength of the optical beam that is reflected by the FBG sensors is detected, and if a crack in the component damages the fiber between an FBG sensor and the detector circuit, where one or more of the reflected signals are not received, the detector knows that a crack has occurred. By strategically placing a plurality of the FBG sensors along the fiber, a crack that damages the fiber in multiple locations between multiple FBG sensors, or in multiple fibers, can provide an indication of the length of the crack.

Abstract: One embodiment of the present invention is a unique gas turbine engine. Another embodiment is a unique fuel injection system for a gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and fuel injection systems for gas turbine engines. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

Abstract: A combustor includes a central fuel nozzle assembly and a plurality of outer fuel nozzle assemblies, each of the plurality of outer fuel nozzle assemblies having a center body and an outer shroud, the plurality of outer fuel nozzle assemblies being configured to abut one another in a surrounding relationship to the central cylinder such that no gaps are present between any two abutting ones of the plurality of outer fuel nozzle assemblies. One or more of the plurality of fuel nozzle assemblies may traverse axially back and forth according to embodiments of the invention.

Abstract: A fuel injector device for an annular combustion chamber including a pilot circuit feeding an injector and a multipoint circuit feeding injection orifices formed in a front face of an annular chamber, an annular ring being mounted in the annular chamber to define therein a fuel feed circuit for the injection orifices and a cooling circuit operating by passing the fuel feeding the injector and extending over the front face of the chamber in immediate vicinity of the injection orifices.

Abstract: A fuel injector device for an annular combustion chamber of a turbine engine, including a pilot circuit feeding an injector and a multipoint circuit feeding injection orifices formed in a front face of an annular ring mounted in an annular chamber, together with a thermal insulation mechanism insulating the front face and including an annular cavity formed around the injection orifices between the front face of the annular ring and a front wall of the annular chamber and configured to be filled in operation with air or with coked fuel.

Abstract: A combustor liner has a plurality of resonators formed thereon. Each resonator has a radially outer wall and at least one side wall. The outer wall can be free of holes. Each resonator has an inner cavity defined between the outer wall, the at least one side wall and the outer peripheral surface of the liner. The at least one side wall of each resonator surrounds a subset of a plurality of holes that extend substantially radially through the liner. A plurality of cooling passages extends generally longitudinally within the liner. Each cooling passage has an inlet in fluid communication with the exterior of the liner and an outlet in fluid communication with the inner cavity of a respective one of the resonators. A coolant, such as compressor air, can enter and flow along the cooling passages to thereby cool the liner and purge the inner cavity of the resonator.

Abstract: A method and apparatus for cooling a combustor liner in a combustor are disclosed. In one embodiment, a combustor is disclosed. The combustor includes a transition piece, and an impingement sleeve at least partially surrounding the transition piece and at least partially defining a generally annular flow path therebetween. The combustor further includes an injection sleeve mounted to one of the transition piece or the impingement sleeve and positioned radially outward of the impingement sleeve, the injection sleeve at least partially defining a flow channel configured to flow working fluid to the flow path. In another embodiment, a method for cooling a combustor liner in a combustor is disclosed. The method includes flowing a working fluid through a flow channel at least partially defined by an injection sleeve, and exhausting the working fluid from the flow channel into a flow path adjacent the combustor liner.

Abstract: A turbomachine combustor includes a combustion chamber; a plurality of micro-mixer nozzles mounted to an end cover of the combustion chamber, each including a fuel supply pipe affixed to a nozzle body located within the combustion chamber, wherein fuel from the supply pipe mixes with air in the nozzle body prior to discharge into the combustion chamber; and wherein at least some of the nozzle bodies of the plurality of micro-mixer nozzles have axial length dimensions that differ from axial length dimensions of other of the nozzle bodies.

Abstract: A condition measurement apparatus is provided and includes a gas turbine engine combustor having an end cover, a liner defining a liner interior and a fuel nozzle communicative with the liner interior, the end cover being formed to separate a cold side thereof, which is a relatively low temperature environment, from a hot side thereof, which is a relatively high temperature environment in which the liner and the fuel nozzle are disposed, the combustor being formed to define a fuel flow path extending through piping disposed at the cold side of the end cover by which fuel is deliverable to the fuel nozzle, and a condition sensing device operably mounted on the piping.

Abstract: A ring element for a turbomachine, in particular for an aircraft gas turbine, is disclosed. The ring element has a ring element main body that has two adjacently arranged ring ends, the ring ends being connected to one another in a form-locking manner with respect to an axial plane. Also disclosed is a turbomachine having at least one such ring element.

Abstract: The invention refers to a thermal control device for controlling the temperature of a heat source by means of transferring heat from the heat source to the ambient environment, through the circulation of a fluid in the device, said device comprising an evaporator (10) collecting heat from the heat source, a condenser (30) rejecting heat to the ambient environment, a compensation chamber (20), and liquid (50) and vapor (40) transport lines connecting the evaporator (10) and the condenser (30), the fluid flowing through said transport lines (40, 50), the device further comprising a thermal electrical cooler (90), the thermal electrical cooler (90) further comprising a thermal saddle (80) attached to the cold side of the thermal electrical cooler (90), and a thermal radiator (100) attached to the hot side of the thermal electrical cooler (90), such that heat is rejected to the ambient environment directly through the thermal radiator (100), when the thermal control device operates in a hot environment, the ambie

Abstract: A device for emergency cooling a beverage receptacle which includes a transparent plastic cup shaped holder sized to receive the beverage receptacle therein. A solvent is placed into the cup shaped holder. A chemical element is placed into the cup shaped holder, whereby when the chemical element is mixed with the solvent it will produce an endothermic reaction. When the beverage receptacle is placed within the cup shaped holder the endothermic reaction will remove heat from the beverage within the beverage receptacle and cool the beverage.

Abstract: Disclosed are a cleaning device of an ice maker and a method thereof. In the cleaning device of an ice maker and a method thereof according to embodiments of the present invention, since the cleaning block is detachably coupled to the ejector to clean the ice making container, a cleaning operation can be easily performed on the ice making container, which is difficult for an operator to directly clean, thereby enhancing quality of ice made by the ice maker.

Abstract: A produce storage chamber comprising a chamber capable of encasing produce, a refrigeration system, at least one ozone generation units, and at least one ethylene scrubbers. The chamber is capable of delaying postharvest produce deterioration using at least one of temperature control, ozone generation, and ethylene scrubbing.

Abstract: A refrigeration appliance includes a storage compartment. An evaporator cools the storage compartment. A defrost heater is associated with the evaporator. A temperature sensor senses an evaporator temperature and generates a temperature signal based on the evaporator temperature. A controller receives the temperature signal and generates a defrost heater power control signal. A power supply receives the defrost heater power control signal and controls a power level supplied to the defrost heater based on the defrost heater power control signal. A first power level is supplied to the defrost heater during a first heating interval of a defrosting operation, and, based on an evaporator temperature rise occurring during the first heating interval, the controller adjusts the defrost heater power control signal such that an adjusted power level is supplied to the defrost heater during a second heating interval of the defrosting operation.

Abstract: A system, apparatus, and method for determining when an amount of ice formed on an evaporator or evaporator grid has reached a predetermined size are illustrated. An acoustic transmitter an acoustic transmitter positioned proximate to the evaporator channels acoustic signals emanating from the evaporator or evaporator grid to an acoustic sensor, which generates an electronic signal indicative of the acoustic signal. A receiver module coupled to the acoustic sensor is configured to receive the electronic signal and determine that ice formed on the evaporator has reached a predetermined size based on the electronic signal.

Abstract: Methods and systems are provided for controlling an air conditioning system of a vehicle, the air conditioning system having a condenser fan, are provided. An ambient temperature is obtained. A power setting for the condenser fan is controlled such that energy usage of the air conditioning system is minimized, using the ambient temperature and other available inputs.

Abstract: Embodiments of systems, apparatus, and/or methods can provide a supply air delivery system to modify delivered supply air responsive to a sensed condition. Embodiments of transport refrigeration systems, air delivery chutes, plenums in containers, containers and methods for using same according to the application can maintain a prescribed environment for an operatively coupled cargo or a container.

Abstract: A method and apparatus are disclosed for controlling dehumidification of an airflow to be conditioned for supply to a climate controlled space. The airflow to be conditioned is passed over a plurality of refrigerant conveying conduits of an evaporator of a refrigerant vapor compression thereby cooling the airflow. A controller operates the refrigeration vapor compression system to maintain the airflow at a set point air temperature indicative of a desired temperature within the climate controlled space. The controller also adjusts an evaporator expansion device for controlling the flow of refrigerant through the evaporator so as to reduce the temperature of the refrigerant within the refrigerant conveying conduits of the evaporator whenever further dehumidification of the air flow to be conditioned is desired.

Abstract: The present disclosure provides a refrigerant vapor compression system includes a compressor (12) having a suction port and a discharge port, a refrigerant heat rejection heat exchanger (24) operatively coupled downstream to the discharge port of the compressor, a refrigerant heat absorption heat exchanger (42) operatively coupled downstream to the refrigerant heat rejection heat exchanger, a compressor suction inlet line connecting the refrigerant heat absorption heat exchanger to the suction port of the compressor, and an adiabatic expansion device (54) operatively coupled to the suction inlet line. A sensor operatively coupled to the suction inlet line measures a superheat value of the refrigerant. The refrigerant vapor compression system further includes a controller (60) in communication with the sensor.

Abstract: An engine and an electronic control unit perform cooling capacity increase control for compensating for a insufficiency of the cooling capacity of a cooling device. The electronic control unit performs a variety of control for a vehicle, including control of the cooling device. At that time, the electronic control unit calculates the target value of the cooling capacity of the cooling device, calculates the estimate value of the cooling capacity that will be able to be exerted in the future under the current control, compares the target value and the estimate value, and when it is determined from the result of the comparison that the cooling capacity will be insufficient, performs the cooling capacity increase control. The electronic control unit changes the contents of the cooling capacity increase control according to the degree of insufficiency of the estimate value with respect to the target value.

Abstract: The use of the following techniques to clean air: (1) inlet air filtration, (2) continuous recirculation air filtration, (3) water filtration and disinfection, (4) use of an air curtain in the ice bin opening, and (5) provision of clean air to the air assist pump during the harvest cycle.

Abstract: The cooling chest for rapidly quenching beverages includes a quench tray for holding containers of beverage. The quench tray is lowered into salt-water or other cooling liquid which is cooled by a refrigeration unit. A processing device determines the temperature of the beverages within the containers within the quench tray and further activates a mechanism for removing the quench tray from the water or cooling liquid when the desired temperature is reached. The processing device can also activate the mechanism for removing the quench tray from the water or cooling liquid when the upper lid or access doors are opened.

Abstract: To provide an air-conditioning apparatus capable of achieving energy saving. An air-conditioning apparatus includes at least a use side heat medium flow control device and a first heat medium flow switching device disposed in an outlet side of the heat medium passage of a use side heat exchanger, and a heat medium backflow prevention device disposed in an inlet side of the heat medium passage of a use side heat exchanger.

Abstract: Obtained is an air-conditioning apparatus that is capable of saving energy. A pressure in a passage of the second refrigerant flow switching device in which a refrigerant from an outdoor unit flows into is higher than a pressure in a passage of the second refrigerant flow switching device in which the refrigerant flows out to the outdoor unit regardless of switching states of a first refrigerant flow switching device, the second refrigerant flow switching devices, and a third refrigerant flow switching device.

Abstract: An air-conditioning apparatus includes indoor units including a plurality of use side heat exchangers that exchange heat between air and a heat medium, and a heat medium relay unit having a plurality of heat exchangers related to heat medium. A plurality of pumps deliver the heat medium involved in heating or cooling performed by the plurality of heat exchangers related to heat medium to each passage and circulate the heat medium. A plurality of heat medium flow switching devices perform switching so that the heat medium from a selected passage flows into and flows out of each use side heat exchanger. An expansion tank is connected to a passage alleviates a pressure change caused by a volumetric change of the heat medium, and a pressure equalizing pipe connects each inlet passage or each outlet passage of the heat medium sending devices.

Abstract: A HVAC-APU system is provided for a battery electric vehicle. The system includes, but is not limited to a refrigerant fluid. A power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section are in selective fluid communication with each other to advance the refrigerant fluid through the system. A compressor-expander train includes, but is not limited to a reversing compressor-expander and a high-pressure pump that are operably connected by a shaft. The high-pressure pump pressurizes the refrigerant fluid to form a high-pressure refrigerant fluid. An auxiliary fuel cell and combustion unit heats a heat transfer fluid. A heat exchanger transfers heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid. The reversing compressor-expander expands the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

Abstract: The invention concerns a refrigeration system comprising a refrigerant circuit which comprises several evaporator paths and a distributor (5) which distributes the refrigerant on the evaporator paths. The aim of the invention is to improve the operation of said refrigeration system in a simple manner. According to the invention, the distributor (5) comprises a controllable valve (12) for each evaporation path.

Abstract: A heat pump for a heat source tower using secondary solar energy, including a cold and heat source tower, a low heat source heat pump, a condensation water separate device used in winter, a looping system at a cold and heat source side, and a circulating system at a terminal load side.

Abstract: The present invention relates to a heating device with irreversible thermodynamic cycle. The device comprises a low temperature circuit and a high temperature circuit in which respectively a first and a second operating fluid circulate. Each circuit comprises evaporating, compression, condensation and expansion means of the respective operating fluid. The low temperature circuit absorbs thermal energy from a supply water flow for evaporating the first operating fluid. The thermal energy deriving from the condensation of the first operating fluid is used for evaporating the second fluid. Instead, the thermal energy deriving from the condensation of the second fluid is used for heating a delivery water flow. According to the invention, the two operating circuits each comprise cooling means interposed between the corresponding condensation and expansion means.

Abstract: An air-conditioning apparatus including an outdoor unit having a compressor compressing a refrigerant and a heat source side heat exchanger exchanging heat between the refrigerant and air; a plurality of indoor units having use side heat exchangers exchanging heat between a heat medium that flows therein and air; and a relay unit disposed between the outdoor unit and the indoor units, the relay unit exchanging heat between the refrigerant conveyed from the outdoor unit and the heat medium flowing in the indoor units, in which the relay unit includes a main relay unit that is connected to the outdoor unit with two pipings and a sub relay unit that is connected to the main relay unit with three pipings.

Abstract: Natural and/or Processed Hydrophilic Earthen Minerals (water loving rocks) formed into an air-water interface matrix will track only a few degrees above local wet bulb temperature with the addition of water. Coating surfaces, Building Roofs and Walls, with hydrophilic earthen rocks and adding water will cool the building mass below air temperature. Wet bulb temperature is the lowest temperature that can be reached by the evaporation of water only. It is the temperature you feel when your skin is wet and is exposed to moving air. The wet bulb temperature is lower than ambient air temperature, except during rain. Water is added periodically to maintain hydration and wet bulb temperature tracking. Hydrophilic Earthen Minerals are UV Stable, expand surface area for evaporation and are fireproof.

Abstract: A rotating valve includes an inlet region, an outlet region, and a switching region having a switching member that can be rotated about an axis. In a first position of the switching member the plurality of inlets are connected to the plurality of outlets in a first association, and in a second position of the switching member the plurality of inlets are connected to the plurality of outlets in a second association. The switching member has a plurality of openings through which the fluid flows flow axially in the direction of the rotation axis and are moved together with the switching member. The openings alternately cover a plurality of stationary, axially directed openings in the course of the rotation of the switching member. Different associations of the inlets with the outlets are carried out by the alternating covering of the axially directed openings.

Abstract: An evaporator includes a pair of header tanks spaced from each other in a vertical direction; a plurality of flat heat exchange tubes 45 which are disposed between the two header tanks such that their width direction coincides with a front-rear direction and they are spaced from one another in a left-right direction, opposite ends portions of the flat heat exchange tubes being connected to the corresponding header tanks; and corrugated fins 5 each disposed between adjacent heat exchange tubes 45. Each of left and right portions of front and rear end walls 45a of each heat exchange tube 45 has a straight slope portion 55 which inclines outward in the front-rear direction, toward a center portion of the heat exchange tube 45 with respect to the left-right direction. The angle formed between the slope portion 55 and the left edge or right edge of the corresponding corrugated fin 5 is set to 25 to 40 degrees.

Abstract: The invention relates to a method for cooling a single-component or multi-component stream, in particular a hydrocarbon-rich fraction, by indirect heat exchange with the refrigerant mixture of a refrigerant mixture circuit. The refrigerant mixture is compressed in at least two stages and is separated into a lower-boiling refrigerant mixture fraction compressed to the ultimate pressure of the refrigerant mixture circuit and at least one higher-boiling refrigerant mixture fraction compressed to an intermediate pressure. The latter is pumped (P11) to the pressure of the former and the two fractions are combined before or immediately on commencement of indirect heat exchange.

Abstract: A system for conversion of waste and solar heat energy into a carbon sequestration device, including as a collector for collecting carbon dioxide gas from a carbon dioxide gas source, such as ambient air. The Joule Thompson effect is used to cool and thereby refrigerate/liquefy ambient air and then extracting carbon dioxide therefrom, comprising steps of and means for providing a hydride heat engine, operating the hydride heat engine utilizing hydride thermal compression technology to compress hydrogen gas and thereby to cool ambient air to a temperature rendering air into a refrigerated/liquefied state by use of a Joule-Thompson type process, and extracting carbon dioxide from the refrigerated/liquefied ambient air and collecting the carbon dioxide.

Abstract: Housing insert (2) for a spacer (3) of a ceramic link (1) for a bracelet (1000), including a housing (4) for receiving a spacer (3) having one end (9). It includes an external machined portion (6) arranged to cooperate with said housing (4) and an internal machined portion (7) including a substantially cylindrical bearing area (8), arranged to closely receive said end (9) and having a smaller diameter than that of said end (9). Equipped link (10) including a link (1) of this type and an insert (2) of this type fixed in said housing (4). Bracelet (1000) including a plurality of equipped lateral (13) links (10) into which removably mounted spacers (3) are driven. Bracelet (1000) including intermediate links (14) assembled to pivot freely relative to said spacers (3) or relative to pins (12) pivotably mounted in said equipped links (10).

Abstract: A device and method is provided to enable the enlargement of a piercing to a desired diameter. The device includes a series of units with each unit consisting of a plug body, a front end cap and a rear end cap and each unit increasing in size compared to the previous unit in the series. Each unit is able to securely attach to the previous unit and enable it to push the previous unit out of the piercing as it is pushed into the piercing.

Abstract: Articles of jewelry, including ring assemblies (100, 300, 400, 700, 1300) permitting secured, removable, rotatable, placement of rings within such ring assemblies (100, 300, 400, 700, 1300). In some embodiments, an ornamental support structure (412, 712, 715, 1312) comprises a hinge permitting a rotatable movement of a portion of the ring assembly to permit placement of the ring structure. In other embodiments, pinch clasps (520, 620, 820, 920, 1020, 1120, 1220, 1320) are used for such ring assemblies.

Abstract: To provide a method of producing a reinforced antireflection glass, which reinforces the glass by a chemically reinforcing treatment based on the ion-exchange method after the antireflection film has been formed.

Abstract: A manufacturing method of a glass strip, the method including a heating and drawing process of heating and softening a glass plate preform, drawing the glass plate preform to have a desired thickness, and forming a glass strip, wherein at the heating and drawing process, the glass plate preform is drawn so that an internal pressure of a heating furnace is kept positive relative to an atmospheric pressure and so that gas flows introduced to both surfaces of the glass plate preform, respectively are equal to each other within the heating furnace.

Abstract: The present invention relates to a method of shaping a glass sheet in one dimension, by roll forming in a manner to selectively minimize/eliminate undesired curvature from the glass sheet. Such shaping is achieved by the selective location in first and second, shaping zones, of shaping rolls having first and second shaping configurations and , optionally, by varying the velocity of the glass sheet as it moves through the shaping zones, thus varying the time portions of the glass sheet are in contact with certain shaping rolls.

Abstract: A method for producing an optical fiber preform according to the present invention includes a collapse step of collapsing a silica-based glass tube by heating with a heat source continuously traversed in the longitudinal direction of the glass tube to form a first glass rod to be formed into a core part or part of a core part of an optical fiber, the glass tube having an inner surface doped with an alkali metal, in which the glass tube has a maximum alkali metal concentration of 500 to 20,000 atomic ppm, a maximum chlorine concentration of 0 to 1000 atomic ppm, and a maximum fluorine concentration of 0 to 10,000 atomic ppm, and in which in the collapse step, the maximum temperature of the outer surface of the glass tube is 2000° C. to 2250° C., and the traverse speed of the heat source is 30 mm/min to 100 mm/min.

Abstract: A method for producing an optical fiber preform according to the present invention includes an etching step of heating a silica-based glass tube using a heat source continuously traversed in the longitudinal direction of the glass tube to etch the inner surface portion of the glass tube containing impurities while an etching gas is allowed to flow into the glass tube. The glass tube has a maximum alkali metal concentration of 500 to 20,000 atomic ppm, a maximum chlorine concentration of 0 to 1000 atomic ppm, and a maximum fluorine concentration of 0 to 10,000 atomic ppm. In the etching step, the maximum temperature of the outer surface of the glass tube is in the range of 1900° C. to 2250° C., and the heating time is set to a time equal to or less than a time (min) given by ( 7 - alkai ? ? metal ? ? concentration ? ? ppm 5000 ) .