Abstract: A bi-stable popper valve and a device for detecting blockage in a flow of a fluid are provided. The valve includes a membrane supporting two conformations: in a first conformation the membrane is convex in relation the upstream fluid, and in a second conformation the membrane can be concave in relation to the upstream fluid, such that in the first conformation the flow of the fluid through the membrane is prevented and in the second conformation the flow of the fluid through the membrane is permitted through a pore defined by the membrane in only the second conformation. The membrane changes from the first conformation to the second responsive to a pressure of the fluid meeting or exceeding an opening pressure value of the membrane. A sensor can detect a shift from the first conformation to the second conformation, indicating a flow, or absence of flow, of the fluid.

Abstract: A bi-stable popper valve and a device for detecting blockage in a flow of a fluid are provided. The valve includes a membrane supporting two conformations: in a first conformation the membrane is convex in relation the upstream fluid, and in a second conformation the membrane can be concave in relation to the upstream fluid, such that in the first conformation the flow of the fluid through the membrane is prevented and in the second conformation the flow of the fluid through the membrane is permitted through an pore defined by the membrane in only the second conformation. The membrane changes from the first conformation to the second responsive to a pressure of the fluid meeting or exceeding an opening pressure value of the membrane. A sensor can detect a shift from the first conformation to the second conformation, indicating a flow, or absence of flow, of the fluid.

Abstract: In one embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali. In another embodiment, a method for forming an alkali resistant coating includes forming two or more alternating layers of high and low refractive index oxide materials above a substrate, wherein an innermost layer of the two or more alternating layers is on an alkali-contacting side of the alkali resistant coating, and wherein the innermost layer of the two or more alternating layers comprises at least one of: alumina, zirconia, and hafnia.

Abstract: A method and system for calorimetrically measuring the temperature-dependent absorptivity of a homogeneous material dimensioned to be thin and flat with a predetermined uniform thickness and a predetermined porosity. The system includes a material holder adapted to support and thermally isolate the material to be measured, an irradiation source adapted to uniformly irradiate the material with a beam of electromagnetic radiation, and an irradiation source controller adapted to control the irradiation source to uniformly heat the material during a heating period, followed by a cooling period when the material is not irradiated.

Abstract: A method and system for calorimetrically measuring the temperature-dependent absorptivity of a homogeneous material dimensioned to be thin and flat with a predetermined uniform thickness and a predetermined porosity. The system includes a material holder adapted to support and thermally isolate the material to be measured, an irradiation source adapted to uniformly irradiate the material with a beam of electromagnetic radiation, and an irradiation source controller adapted to control the irradiation source to uniformly heat the material during a heating period, followed by a cooling period when the material is not irradiated.

Abstract: In one embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali. In another embodiment, a method for forming an alkali resistant coating includes forming two or more alternating layers of high and low refractive index oxide materials above a substrate, wherein an innermost layer of the two or more alternating layers is on an alkali-contacting side of the alkali resistant coating, and wherein the innermost layer of the two or more alternating layers comprises at least one of: alumina, zirconia, and hafnia.

Abstract: In one embodiment, a multilayer dielectric coating for use in an alkali laser includes two or more alternating layers of high and low refractive index materials, wherein an innermost layer includes a thicker, >500 nm, and dense, >97% of theoretical, layer of at least one of: alumina, zirconia, and hafnia for protecting subsequent layers of the two or more alternating layers of high and low index dielectric materials from alkali attack. In another embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali.

Abstract: In one embodiment, a multilayer dielectric coating for use in an alkali laser includes two or more alternating layers of high and low refractive index materials, wherein an innermost layer includes a thicker, >500 nm, and dense, >97% of theoretical, layer of at least one of: alumina, zirconia, and hafnia for protecting subsequent layers of the two or more alternating layers of high and low index dielectric materials from alkali attack. In another embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali.

Abstract: Compounds represented by the following structure (I), acid-addition salts and pro-drugs are disclosed: wherein the ring structure includes no substitutions, one substitution, or more than one substitution; and wherein n is equal to an integer grater than 1, preferably 2, 3, or 4; m is equal to a positive integer, preferably 1, 2 or 3, and each separate Xn and X are each separately selected from a nucleophilic residue, preferably —H, —OH, —O—CO-alkyl, —O-alkyl, —NH2, a halogen and the like; and wherein the dashed line represents a C—C bond or a C—H bond, and the dashed and solid line represents either a carbon-carbon single bond or a carbon-carbon double bond.

Abstract: Compounds represented by the following structure (I), acid-addition salts and prodrugs are disclosed: 1

Abstract: Parasitic oscillations are eliminated in solid-state laser components by applying a pattern of grooves to the peripheral sections that do not transmit the desired laser radiation. Additionally, the invention frustrates total internal reflections at polished peripheral component walls by providing a pattern of roughened surface sections in between polished sections. The roughened surfaces may be only microns deep or may be as deep as a few centimeters for large components. The grooves should be sufficiently deep as to inhibit any total internal reflections. The invention applies to all common solid-state architectures that are designed with polished surfaces that do not serve to propagate the desired laser radiation. Examples are slabs, plates, laser rods, waveguides and disks functioning as laser oscillators or amplifiers. The invention is operational with conventional crystal or glass laser hosts or with hosts that are composites of same, similar or dissimilar crystals or glasses.