3-piperidino-4-hydroxychroman derivs. of formula (I) and their salts are new, where A and B = H or A with B = -CH2CH2-. X = CH2 or O. X1 = H or OH. Z = H, F, Cl, Br or OH. Z1 = H, F, Cl, Br or 1-3C alkyl. n = O or 1; m = 0 or 1-6. When X = 0 (I) pref has cis stereochemistry. (I) are prepd. by hydride redn. of a suitable alpha-aminoketone, using e.g. NaBH4 in THF at -15 to 15 deg.C.

Improved cementitious compositions having increased flexural, tensile and shear-bond strength, increased wear resistance, decreased water permeability and enhanced workability than previous cement compositions, which are prepared with water treated with an emulsified tar component, and preferably a residual amount of sodium tripolyphosphate, are provided. Methods of forming shaped articles therefr...

In the operating procedure for a circular or annular pre-clarifier tank with a sludge removal system, a horizontal circular flow is temporarily produced in the tank or an annular section of the tank and during this time the sludge removal system is taken out of operation.Also claimed is a pre-clarifier tank in which: the tank (1) is divided by an annular intermediate all (17) into inner and outer ...

A process is described for the acclimation and en ment of an activated sludge culture for the degradation of high concentrations of methanesulfonic acid, so as to render it non-toxic to the aquatic environment

A support structure (10) for supporting a load (C) comprises a core (12) of connected strips (14) including spacer strips (16) of corrugated material and at least one bent strip (18) having a plurality of laminated layers (20). The bent strip (18) is disposed between opposing spacer strips (16) and secured at bend surfaces (22) along the bent strip (18). The bent strip (18) and the opposing spacer...

A tape comprising a biaxially-oriented backing made from a polymeric film bearing on one major surface thereof a layer of pressure-sensitive adhesive and on the other major surface thereof a layer of low-adhesion backsize composition. The backing and the layer of pressure-sensitive adhesive intermix so as to form a commingled layer between them. This invention also provides a process of preparing ...

A process is described for the operation of a multiple zone batch treatment system for biological or biophysical treatment of wastewater. The system comprises two or more batch treatment zones (10,12) with wastewater passing sequentially through all treatment zones. After the mix and settle batch steps occur for all zones, influent wastewater flows into the first zone (10) and displaces clarified ...

The present invention relates to the activation and deactivation of a transistor (Q1) in a final stage (10), for instance a push-pull final stage. The final stage is included in a voltage alternating drive system connected to a load. A current driving buffer circuit (24) in the drive system is connected to the transistor (Q1) and functions to activate and deactivate the transistor, i.e. to switch ...

The present invention relates to the activation and deactivation of a transistor (Q1) in a final stage (10), for instance a push-pull final stage. The final stage is included in a voltage alternating drive system connected to a load. A current driving buffer circuit (24) in the drive system is connected to the transistor (Q1) and functions to activate and deactivate the transistor, i.e. to switch ...

A stepping motor for adjusting actuation elements is proposed, having an electronic control device in which the stepping motor is driven as a function of operating parameter with a respectively required number of actuation steps in order to adjust a desired quantity of injected fuel, a preferred position of the actuation element (7) actuated by the stepping motor (17) being detected as a position ...

A data cache in a computer operating system that dynamically adapts its size in response to competing demands for processor storage, and exploits the storage cooperatively with other operating system components. An arbiter is used to determine the appropriate size of the cache based upon competing demands for memory. The arbiter is entered cyclically and samples user's wait states. The arbiter the...

In an implant having sliding surfaces which slidingly move toward each other one sliding partner (1) is made of a relatively soft material and the other sliding partner is made of a relatively hard material in comparison. The sliding surface (5) of the relatively soft sliding partner (1) is covered with supporting bodies (3) consisting of a hard material, especially of the same material as the har...

PCT No. PCT/FR91/00007 Sec. 371 Date Jul. 29, 1992 Sec. 102(e) Date Jul. 29, 1992 PCT Filed Jan. 8, 1991 PCT Pub. No. WO91/11405 PCT Pub. Date Aug. 8, 1991.Method for eliminating the dangerous alkali-aggregate reaction in concretes which contain hydrated cement obtained by the alkaline activation of Portland cement. The formation in this concrete of a compound which can generate a soluble alkali a...

The invention relates to a method for producing and concentrating alkaline silica sols containing non-aggregated spherical SiO2 particles having a diameter of >/= 4 nm, starting from SiO2 concentrations of from 4 to 8 % by weight with the use of microporous membrane filters.

The biological decontamination of earth and other materials, contaminated waste and/or other organic matter involves cultivation of bacteria, to give optimum biodegrading of the hydrocarbons.

For the biological decontamination of wood materials, contaminated by wood preservatives, the material is mixed with organic domestic waste and/or other organic matter, to give the optimum conditions for bacterial cultivation to biodegrade the contamination.

A communication system having a plurality of service control points which can be mutually coupled and are assigned to at least one service switching point for executing services, a database system, and a service management system for managing the services. To enhance the availability of the database system, this database system comprises distributed databases which have each a database control poi...

A device to unlock a car and start its engine, has a hand-held transmitter (10) sending a coded signal (21). On the car is a receiver (24) and an evaluation stage (23) to verify the coded signal. A first control unit (33) connected to the receiver is used to open the car door (30). There is a second control unit (60) also connected to the receiver which unlocks the door after successful verificati...

The pH value of potable water in a water treatment plant is adjusted by controlled automatic addition of a treatment chemical, to alter the acidity. The measured mains water throughput of the plant is used in the treatment algorithm together with a second variable, x2, a chemical concentration value. The set point is adjusted on the basis of a regular water analysis. Also claimed is a process whe...

A depot formulation contg. clindamycin palmitate is claimed. Pref. implants contain 5-250 mg. clindamycin palmitate per cubic cm. Examples of typical implants are bone replacements, heart valves and sutures for these and artificial blood vessels.