Abstract: The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber.

Abstract: A combustion system configured to receive fuel from a plurality of fuel sources, wherein the combustion system includes a burner, a shutter, a fuel selector, and an electronic controller configured to receive an indication of a selected fuel type from the fuel selector and output instructions for the shutter to adjust to a shutter position associated with the selected fuel type, the shutter position being configured to provide a predetermined supply of air to thereby effect an air-to-fuel ratio associated with combustion of the selected fuel type.

Abstract: A baffle for a thermal transfer device can include a body having a multiple first apertures that traverse therethrough, where each first aperture has a first outer perimeter that includes a first base shape and at least one first protrusion extending from the first base shape. Each of the first apertures is configured to receive a tube. The first base shape of each first aperture has a first shape and a first size that is configured to be substantially the same as the first shape and the first size of an end of a tube.

Abstract: A fastening device for fluid tightly coupling a first duct body and a second duct body of a heat exchanger is provided. The fastening device includes a support member to couple with a connecting edge of the first duct body. The support member includes a pivot pin and a locking device disposed at an offset distance from the pivot pin along a radial axis of the fastening device. The fastening device further includes a pivot arm having a first end to engage with the pivot pin and a second end to engage with a flange of the second duct body. The locking device engages with the pivot arm and move the second end of the pivot arm relative to the pivot pin to fluid tightly engage the flange of the second duct body with the connecting edge of the first duct body.

Abstract: A baffle for a fluid collection portion of a thermal transfer device can include a body having an inner perimeter, an outer perimeter, and an asymmetric feature, where the asymmetric feature is configured to create a pressure drop within the fluid collection portion of the thermal transfer device. The inner perimeter can be configured to be at least as large as an inner surface of a first wall that forms the fluid collection portion of the thermal transfer device. The outer perimeter can be configured to be no larger than an outer surface of a second wall that forms the fluid collection portion of the thermal transfer device.

Abstract: A baffle for a fluid collection portion of a thermal transfer device can include a body having an inner perimeter, an outer perimeter, and an asymmetric feature, where the asymmetric feature is configured to create a pressure drop within the fluid collection portion of the thermal transfer device. The inner perimeter can be configured to be at least as large as an inner surface of a first wall that forms the fluid collection portion of the thermal transfer device. The outer perimeter can be configured to be no larger than an outer surface of a second wall that forms the fluid collection portion of the thermal transfer device.

Abstract: The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber.

Abstract: A baffle for a thermal transfer device can include a body having a multiple first apertures that traverse therethrough, where each first aperture has a first outer perimeter that includes a first base shape and at least one first protrusion extending from the first base shape. Each of the first apertures is configured to receive a tube. The first base shape of each first aperture has a first shape and a first size that is configured to be substantially the same as the first shape and the first size of an end of a tube.

Abstract: The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber.

Abstract: A baffle for a thermal transfer device can include a body having a multiple first apertures that traverse therethrough, where each first aperture has a first outer perimeter that includes a first base shape and at least one first protrusion extending from the first base shape. Each of the first apertures is configured to receive a tube. The first base shape of each first aperture has a first shape and a first size that is configured to be substantially the same as the first shape and the first size of an end of a tube.

Abstract: The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber.

Abstract: A baffle for a thermal transfer device can include a body having a multiple first apertures that traverse therethrough, where each first aperture has a first outer perimeter that includes a first base shape and at least one first protrusion extending from the first base shape. Each of the first apertures is configured to receive a tube. The first base shape of each first aperture has a first shape and a first size that is configured to be substantially the same as the first shape and the first size of an end of a tube.

Abstract: A baffle for a fluid collection portion of a thermal transfer device can include a body having an inner perimeter, an outer perimeter, and an asymmetric feature, where the asymmetric feature is configured to create a pressure drop within the fluid collection portion of the thermal transfer device. The inner perimeter can be configured to be at least as large as an inner surface of a first wall that forms the fluid collection portion of the thermal transfer device. The outer perimeter can be configured to be no larger than an outer surface of a second wall that forms the fluid collection portion of the thermal transfer device.

Abstract: The present disclosure provides methods and compositions including a sugar and a choline hydrogen phosphate salt for preservation and stabilization of materials in the amorphous state. The compositions and methods suppress the formation of crystals in materials in the amorphous state.

Abstract: The present disclosure provides methods and compositions including a sugar and a choline hydrogen phosphate salt for preservation and stabilization of materials in the amorphous state. The compositions and methods suppress the formation of crystals in materials in the amorphous state.

Abstract: The present disclosure provides methods and compositions including a sugar and a choline hydrogen phosphate salt for preservation and stabilization of materials in the amorphous state. The compositions and methods suppress the formation of crystals in materials in the amorphous state.