Abstract: In a lens system of five groups of five lens elements in which a front group of two lens elements and a back group of two lens elements are symmetrically arranged on either side of a biconvex lens centrally located therebetween, a copying lens characterized in that the lens elements in sequence from the object comprise a first lens having a positive meniscus configuration with its convex surface directed toward an object, the second lens having a biconcave configuration, a third lens having a biconcovex configuration, a fourth lens having a biconcave configuration and a fifth lens having a positive meniscus configuration with its convex surface being directed toward the image and in which the condition0.2 f<f.sub.3 <0.7 f (1)where,f: overall focal lengthf.sub.3 : focal length of the third lens and the condition0.01 f<d.sub.4 and d.sub.6 <0.09 f (2)whered.sub.1, d.sub.2, d.sub.3, . . . d.sub.9 : the thickness of the lenses and air gaps counted in sequence from the objectare fulfilled.

Abstract: A breathing equipment for high altitude flights comprises a breathing mask provided with a breathing gas regulator capable of supplying breathing gas under pressure and a helmet. The helmet is provided with means which, if the pressure of the breathing gas supplied to the mask is higher than the ambient pressure by an amount exceeding a predetermined threshold, subject those organs of the head which are particularly sensitive to the pressure differential to a gas over-pressure sufficient to avoid physiological troubles.

Abstract: Process and apparatus for the detection and prelocalization of a can fracture in a fuel assembly of a fast nuclear reactor.The device comprises at least one detector for the neutrons emitted by the fission products transported in the outflow of cooling agent as the result of the fracture of a can, said detector being immersed within the vessel in the outflow of cooling agent in an area protected from neutrons emitted by the core by the volume of cooling agent and by structures immersed in the annular space between the core and the vessel.

Abstract: In a feedback control system for maintaining the air-fuel ratio of a combustible mixture fed to an internal combustion engine at a preset ratio, a fluctuation in the output characteristic of an exhaust sensor due to deterioration or low temperature is compensated for by varying a reference voltage, which serves as a standard of comparison, in response to a change in the mean value of the sensor output voltage.

Abstract: A method for packaging an object, in particular a root ball of a tree, shrub or plant. The object to be packaged is placed in a socket which is surrounded by an elastic reticulate hose, whereupon the object is removed from the socket, during which operation the hose is carried along, this hose subsequently being severed beyond the object.An apparatus used for packaging an object, in particular a root ball of a tree, shrub or plant. This apparatus comprises a socket into which the object to be packaged is introduced, as well as a stock of elastic reticulate hose material from which hoses are formed to surround the socket.

Abstract: A solid electrolyte galvanic energy conversion cell capable of being heated to at least 2000.degree. C. containing a form of carbon as a fuel internally and being exposed externally to a source of oxygen, such as air, to cause the passage of oxygen ions through the electrolyte thus causing the formation of CO or CO.sub.2 as desired. The carbon, for example, a rod, is in electrical contact with a solid electrolyte material having an oxygen ion permeability at a temperature of at least 705.degree. C. In one embodiment, an end of the cell is heated at the focal point of a parabolic solar energy collector and generates electrical energy while expelling CO gas which may later be oxidized to CO.sub.2 either by combustion or by means of a secondary galvanic cell to generate additional electrical energy.

Abstract: An exhaust gas recirculation control system for an internal combustion engine, in which a feedback signal representing the amount of actually recirculated exhaust gas is produced by detecting the concentration of either CO.sub.2 or H.sub.2 O, which is contained in the exhaust gas in a nearly constant concentration, in combustible gas mixture diluted with recirculated exhaust gas.

Abstract: A process for recovering caustic alkali from spent alkali liquor, in which a spent alkali liquor and iron oxide are roasted to obtain a product containing alkali ferrate and the product of roasting is hydrolyzed at a temperature over 110.degree. C. and under pressurized conditions where liquid phase is retained, thereby recovering caustic alkali in the form of an aqueous solution of a concentration higher than approximately 15 wt% containing dissolved iron in an extremely small concentration.

Abstract: A fuel control system for internal combustion engines includes a fuel injection control unit responsive to the amount of depression of an accelerator pedal to determine the fuel quantity and an air intake control unit which determines the amount of air to be mixed therewith in response to the determined fuel quantity to correspondingly operate a throttle valve. Fuel and air are supplied to the engine such that they reach the cylinder simultaneously.

Abstract: A speaker system in which at least one driver is mounted on an enclosure and is adapted to radiate sound waves outwardly from said enclosure in response to an input signal. A sound absorbing material is disposed on at least a portion of the outer surface area of said enclosure to reduce the effect of diffractions and reflections of said sound waves relative to said enclosure.

Abstract: A counter is provided for detecting the frequency of generation of collision imminence signals produced in a conventional type of anti-collision radar system for a vehicle. An odometer and/or a clock pulse generator is connected to the counter for applying a reference counting period so that the counter is utilized for generating a signal with which an alerting device which is independent from that of the radar system, is energized when the frequency reaches a predetermined value during the reference counting period.

Abstract: A first annular space is formed between a cylindrical baffle and the reactor vessel and a second annular space is formed between the baffle and a counter-baffle. The level of liquid metal coolant is free within the two annular spaces which are separated by the baffle. The top edge of the baffle has a profile such that they supply of "cold" liquid metal which overflows into the discharge space takes place without breaking away from the baffle wall.

Abstract: A sealing apparatus for joining container parts of a plastic-lightweight al foil laminate by heat and pressure applied to the laminates when the respective plastic layers are pressed into contact uses a toggle linkage and a yieldable buffer, with a hydraulic actuator to drive the toggle linkage to close a pair of sealing heads together. The toggle linkage permits rapid build-up of pressure to a value predetermined by the construction of the buffer, after which the buffer yields to hold the sealing pressure. The duration of the build-up to sealing pressure comprises no more than 20% of the time interval between initiation of pressure build-up and the start of pressure drop-off at the end of the sealing process.

Abstract: The invention relates to an arrangement of a visual shield in the form of an apron bridging the space between an impact receiving member and the end of a vehicle body frame to conceal the mechanical structure. The impact receiving member is located a considerable distance from the end of the vehicle body frame and secured to shock absorbers mounted to the vehicle body frame. An elastomeric spacer is disposed between the visual shield and the impact receiving member so as to prevent direct contact of the visual shield with the impact receiving member.

Abstract: A process for excavating and constructing a tunnel, and an excavating device are disclosed. This process is directed to excavating and constructing a tunnel under a railway or a road on a banking or on level land in the direction transverse to the railway or road. In this process, pits are dug on the opposite sides of the railway, and then an excavator digs into the wall of a pit on one side so as to go out of the wall of the other pit through the ground left therebetween. In this respect, a hollow casing unit of a box shape is coupled to the rear end of the excavator equipped with a screw conveyor. As the excavator advances or digs forwards a given distance, another casing unit is in turn coupled to the rear end of the preceding casing unit, and then such a step is repeated, until the excavator goes out of the wall of another pit. In this manner, the excavator further digs into the wall of one pit in the position adjacent to the preceding run of casing units.

Abstract: Chemicals containing an effective amount of homopolymers of dialkylaminoalkyl acrylate derivatives or dialkylaminoalkyl methacrylate derivatives or copolymers of such derivatives with ethylenically unsaturated monomers copolymerizable therewith. The chemicals exhibit a remarkable effect of preventing agricultural plants from being infected with plant virus diseases. A method for controlling the plant virus diseases is also described.

Abstract: A sheath-package includes two inner sheets disposed adjacent to each other and adapted to be sealed to each other, the outer surfaces of said inner sheets being sterilizable. Two cover sheets are also provided, each of which is disposed adjacent to the outer surface of one of the inner sheets, the inner surface of each cover sheet being sterilizable and adapted to be sealed to its respective adjacent inner sheet. A sheath is formed by joining the inner sheets together along a seal line in the form of a tear seal, the portions of the inner sheets outside of the tear seal forming waste portions, the seal line terminating at two end points to define a mouth adapted for insertion of an instrument into the sheath. A tab is formed by portions of the inner and outer sheets projecting beyond the mouth, the seal line being shaped so that the waste portions connect with the portions of the inner sheets in the tab outside of the seal line.

Abstract: A channel-selecting, presettable, rotary type tuning device in which there is provided a tuning-position-determining unit having two or more tuning-position-determining elements, whose positions may be adjustable; a slide member operably coupled to a variable tuning element and spring-loaded so as to abut the end of each tuning-position-determining element selected due to the rotation of the tuning-position-determining unit; means for rotating the tuning-position-determining unit so as to select a tuning-position-determining element; means for moving back and forth each tuning-position-determining-element thus selected; and means for temporarily releasing the slide member from its abutment on each tuning-position-determining element thus selected.

Abstract: A process for producing styrene from 4-vinylcyclohexene by contacting it with molecular oxygen in a gaseous phase and at an elevated temperature in the presence of a catalyst which contains tin, antimony and oxygen.

Abstract: Apparatus for supporting the body of a person in an upright position to relieve the load of the person's legs, in particular for therapeutic walking exercises, including a seat ring suspended by a cable from a trolley movable on an overhead track. The seat ring has in its rear section an inwardly projecting body support member shaped to engage below the tuber ischii of the person's body and said seat ring having a front section provided with an adjustable pressure pad projecting inwardly from the seat ring front section in opposite relation to the support member, which adjustable pressure pad can be pressed against the symphysis of the pubic bones of the body resting on the body support of the seat ring.