Abstract: This invention relates to an electrode structure including a porous electrode that simultaneously performs the functions both of a bipolar plate and of a felt electrode and has a pattern layer or a mesh layer serving as a flow path on the surface thereof, a method of manufacturing the same, and a redox flow battery stack configuration for decreasing shunt current.

Abstract: A release liner used for manufacturing a membrane electrode assembly includes one or more first films formed of a material having a releasing property, and a second film bonded to the first films and having a tensile strength higher than a tensile strength of the first film. The first films are formed of polytetrafluoroethylene (PTFE) having a non-bonding property and the releasing property.

Abstract: The present invention concerns a method for preparing a catalyst coated membrane including the steps of: coating a substrate with a first catalyst dispersion thereby obtaining a first catalyst dispersion coated substrate, providing a second side of a membrane with a support film, coating a first side of the membrane with a second catalyst dispersion, thereby obtaining a second catalyst dispersion coated first side of the membrane, drying the first catalyst dispersion thereby obtaining a first catalyst coated substrate or drying the second catalyst dispersion coated first side of the membrane thereby obtaining a second catalyst coated first side of the membrane, laminating the first catalyst coated substrate to the second catalyst dispersion coated first side of the membrane or laminating the first catalyst dispersion coated substrate to the second catalyst coated first side of the membrane so that the first catalyst and the second catalyst superimpose, thereby forming a laminate including a membrane compri

Abstract: This invention is directed to electrolysis-based devices and methods for recycling of electrolyte solutions. Specifically, the invention is related to regeneration of spent electrolyte solutions comprising metal ions such as electrolyte solutions used in metal/air batteries.

Abstract: Electrochemical cells can include flow channels designed to provide an electrolyte solution more efficiently to an electrode or ionically conductive separator. Such electrochemical cells can include an ionically conductive separator disposed between a first half-cell and a second half-cell, a first bipolar plate in the first half-cell, and a second bipolar plate in the second half-cell. At least one of the first bipolar plate and the second bipolar plate are a composite containing a conductive material and a blocking material. The blocking material defines a plurality of flow channels that are spaced apart from one another and extend laterally through the composite with respect to the ionically conductive separator. The plurality of flow channels are also in fluid communication with one another in the composite. Such electrochemical cells can be incorporated in electrochemical stacks and/or be fluidly connected to a fluid inlet manifold and a fluid outlet manifold.

Abstract: A power supply apparatus configured to control output power from a fuel cell module that generates power using combustion gas includes a controller that, during operation in parallel with other power supply apparatuses that supply output power from other fuel cell modules to a load, controls the output power from one fuel cell module among the fuel cell module and the other fuel cell modules until the one fuel cell module reaches rated power output, while suppressing the output power from each fuel cell module, other than the one fuel cell module, that has not reached the rated power output.

Abstract: Disclosed herein is a method of manufacturing a battery pack including a battery cell having an electrode assembly received in a battery case, made of a laminate sheet including a resin layer and a metal layer, together with an electrolytic solution.

Abstract: A fuel cell system is provided. The system includes a fuel cell stack, a plurality of valves operated to be selectively opened or closed to supply fuel to the fuel cell stack and remove impurities, and a pressure sensor that detects a state of pressure of fuel supplied to the fuel cell stack. A fuel cell controller then determines whether the pressure sensor or the plurality of valves are faulty by comparing increase or decrease time of the pressure detected by the pressure sensor with a reference range of time delay, as the plurality of valves are operated to be opened or closed.

Abstract: A method for controlling startup of a fuel cell vehicle is provided. The method includes starting to adjust supply of hydrogen and air to a fuel cell and setting a control voltage of a side of a main bus end of a converter disposed between the main bus end and a high-voltage battery to a predetermined lowest control voltage. An output voltage of the side of the main bus end of the fuel cell and the control voltage of the side of the main bus end of the converter are then compared to adjust an amount of air supply to the fuel cell based on the comparison.

Abstract: A method of determining hydrogen deficiency of a fuel cell having a plurality of cell groups includes a reference value storage step of storing, as a reference value, a value of impedance in a state where hydrogen-off gas is discharged from the fuel cell and hydrogen gas and oxidant gas are supplied, a measured value calculation step of calculating a measured value of impedance based on a voltage of the cell groups and a current of the fuel cell, a corrected value calculation step of calculating a corrected value of impedance by correcting the measured value based on the reference value, and a determination step of determining that hydrogen deficiency occurs in a case where the corrected value exceeds a predetermined threshold.

Abstract: A device includes a case having a surface with a perforation and a first cavity containing a gas generating fuel. A first membrane is supported by the case inside the first cavity. The first membrane has an impermeable valve plate positioned proximate the perforation. The first membrane is water vapor permeable and gas impermeable and flexes responsive to a difference in pressure between the cavity and outside the cavity to selectively allow water vapor to pass through the perforation to the fuel as a function of the difference in pressure. A second membrane that is water vapor permeable gas impermeable is coupled between an outside of the case exposed to ambient atmospheric gas and the valve plate creating a reference pressure second cavity configured to reduce the effects of ambient pressure transients on the difference in pressure. A fuel cell membrane may be included in the device to produce electricity.

Abstract: Membrane electrode assembly comprising oxygen evolution reaction catalyst disposed in gas distribution layer (100, 700) or between gas distribution layer (100, 700 and gas dispersion layer (200, 600). Membrane electrode assemblies described herein are useful, for example, in electrochemical devices such as a fuel cell.

Abstract: (Problem) To provide an electrolyte film for fuel cells, capable of achieving both low resistance (film thinning) and high dimensional stability. (Solution) An electrolyte film for fuel cells, the electrolyte film comprising a polymeric electrolyte and a polytetrafluoroethylene (PTFE) porous film, characterized in that a material having an elastic modulus higher than that of the material constituting the PTFE porous film is composited on the inside surfaces of pores of the PTFE porous film, and the composited PTFE porous film has an elastic modulus of at least 150 MPa.

Abstract: Disclosed herein are a lithium air battery having a multi-layered electrolyte membrane and a method of manufacturing the same. The lithium air battery includes a first electrolyte membrane capable of obtaining high ionic conductivity on a lithium negative electrode surface while minimizing the content of polymer and positioning a second electrolyte membrane with high resistance to oxygen radicals on the air electrode. Accordingly, the multi-layered electrolyte membrane can improve an electrolyte filling characteristic and a conductive characteristic of lithium ions, suppress oxygen radicals from being carried from an air electrode, and suppress a growth of lithium dendrite to largely improve a battery lifespan.

Abstract: Flow batteries can be constructed by combining multiple electrochemical unit cells together with one another in a cell stack. High-throughput processes for fabricating electrochemical unit cells can include providing materials from rolled sources for forming a soft goods assembly and a hard goods assembly, supplying the materials to a production line, and forming an electrochemical unit cell having a bipolar plate disposed on opposite sides of a separator. The electrochemical unit cells can have configurations such that bipolar plates are shared between adjacent electrochemical unit cells in a cell stack, or such that bipolar plates between adjacent electrochemical unit cells are abutted together with one another in a cell stack.

Abstract: A fuel cell stack having a structure in which a plurality of single fuel cells C(1) and a plurality of interconnectors (5) are disposed alternately between a pair of end members and such that a junction member J composed of an elastic member (20) and an electrically conductive member (21) is disposed in a space (3a) formed between a first end member (3) and a first interconnector (5(1)). A portion of the electrically conductive member (21) is disposed between the first end member (3) and the elastic member (20), and another portion of the electrically conductive member (21) is disposed between the first interconnector (5(1)) and the elastic member (20); and the first end member (3) and the first interconnector (5(1)) are electrically connected through the electrically conductive member (21).

Abstract: A calcium-based secondary cell including a negative electrode that includes a negative-electrode active material, a positive electrode that includes a positive-electrode active material, an electrolyte arranged between the negative electrode and the positive electrode, and a temperature control element. The negative-electrode active material is capable of accepting and releasing calcium ions, and the positive-electrode active material is capable of accepting and releasing calcium ions. The electrolyte includes calcium ions and an electrolyte medium, and is not solid at a temperature of about 20° C. and a pressure of about 1 atm. The electrolyte medium includes a non-aqueous solvent.

Abstract: This invention provides a non-aqueous electrolyte magnesium secondary battery comprising a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte, the non-aqueous electrolyte comprising [N(SO2CF3)2]? as an anion, and Mg2+ and/or an organic onium cation as a cation.

Abstract: Provided are: a potassium ion secondary battery which is not susceptible to deterioration of charge/discharge capacity even if charging and discharging are repeated, and which has a long service life as a secondary battery; a potassium ion capacitor; a negative electrode for the potassium ion secondary battery; and a negative electrode for the potassium ion capacitor. A negative electrode for potassium ion secondary batteries and a negative electrode for potassium ion capacitors, each of which contains a carbon material that is capable of absorbing and desorbing potassium and a binder that contains a polycarboxylic acid and/or a salt thereof. A potassium ion secondary battery which is provided with the negative electrode or the capacitor. A binder for negative electrodes of potassium ion secondary batteries or negative electrodes of potassium ion capacitors, which contains a polycarboxylic acid and/or a salt thereof.

Abstract: A fluorine-substituted propylene carbonate-based electrolytic solution and a lithium-ion battery, particularly to a fluorine-substituted propylene carbonate-based electrolytic solution having fluorine-substituted propylene carbonate as a primary solvent and a co-solvent is disclosed. The fluorine-substituted propylene carbonate has 50-80 vol. %, and the co-solvent has 20-50 vol. %, based on the volume of the electrolytic solution for a lithium-ion battery.

Abstract: A composite solid electrolyte includes: a lithium ion conductive solid electrolyte; and a polymer-containing electrolyte coating layer on a surface of a lithium ion conductive solid electrolyte, wherein the polymer-containing electrolyte coating layer includes an ion conductive polymer having an alkylene oxide segment.

Abstract: A secondary battery includes a cathode; an anode; and (1) a first polymer compound layer disposed between the cathode and the anode and being adjacent to the cathode, (2) a second polymer compound layer disposed between the cathode and the anode and being adjacent to the anode, or (3) the first polymer compound layer and the second polymer compound layer. One or both of the first polymer compound layer and the second polymer compound layer contain a polymer compound containing fluorine (F) as a constituent element and a conductive material dispersed in the polymer compound.

Abstract: Electrolytes, anodes, lithium ion cells and methods are provided for preventing lithium metallization in lithium ion batteries to enhance their safety. Electrolytes comprise up to 20% ionic liquid additives which form a mobile solid electrolyte interface during charging of the cell and prevent lithium metallization and electrolyte decomposition on the anode while maintaining the lithium ion mobility at a level which enables fast charging of the batteries. Anodes are typically metalloid-based, for example include silicon, germanium, tin and/or aluminum. A surface layer on the anode bonds, at least some of the ionic liquid additive to form an immobilized layer that provides further protection at the interface between the anode and the electrolyte, prevents metallization of lithium on the former and decomposition of the latter.

Abstract: Electrolytes, anodes, lithium ion cells and methods are provided for preventing lithium metallization in lithium ion batteries to enhance their safety. Electrolytes comprise up to 20% ionic liquid additives which form a mobile solid electrolyte interface during charging of the cell and prevent lithium metallization and electrolyte decomposition on the anode while maintaining the lithium ion mobility at a level which enables fast charging of the batteries. Anodes are typically metalloid-based, for example include silicon, germanium, tin and/or aluminum. A surface layer on the anode bonds, at least some of the ionic liquid additive to form an immobilized layer that provides further protection at the interface between the anode and the electrolyte, prevents metallization of lithium on the former and decomposition of the latter.

Abstract: The present disclosure provides a non-aqueous liquid electrolyte comprising a non-aqueous organic solvent, a lithium salt, and an additive that is an isocyanate-based compound comprising a carbon-carbon triple bond. By comprising the isocyanate-based compound additive comprising a carbon-carbon triple bond of the present disclosure in the non-aqueous liquid electrolyte, lifespan properties and high temperature durability are capable of being enhanced, and internal resistance of a battery is capable of being reduced.

Abstract: A homologous series of cyclic carbonate or propylene carbonate (PC) analogue solvents with increasing length of linear alkyl substitutes were synthesized and used as co-solvents with PC for graphite based lithium ion half cells. A graphite anode reaches a capacity around 310 mAh/g in PC and its analogue co-solvents with 99.95% Coulombic efficiency. Cyclic carbonate co-solvents with longer alkyl chains are able to prevent exfoliation of graphite when used as co-solvents with PC. The cyclic carbonate co-solvents of PC compete for solvation of Li ion with PC solvent, delaying PC co-intercalation. Reduction products of PC on graphite surfaces via single-electron path form a stable Solid Electrolyte Interphase (SEI), which allows the reversible cycling of graphite.

Abstract: A problem of the present invention is to provide a rectangular secondary battery in which heat generation of a current collecting plate is suppressed. A rectangular secondary battery of the present invention which solves the above-described problem includes: a flat wound group which is obtained by winding a positive electrode and has a positive electrode metal foil-exposed portion; a battery can which stores the wound group; a battery lid which seals the battery can; a positive electrode external terminal which is provided on the battery lid; and a positive electrode current collecting plate which electrically connects the external terminal and the wound group. The positive electrode current collecting plate includes a fixed portion fixed on the battery lid, a welded portion welded on the metal foil-exposed portion of the wound group, and a joint connecting the fixed portion and the welded portion.

Abstract: An aluminum-based cathode (positive electrode) for storage cells formed by deposition of a layer of aluminum metal on a porous conductive substrate. Storage cells and batteries having the cathode. The porous conducting substrate can be metal, conductive carbon or a refractory material, such as a metal boride or metal carbide. The aluminum-deposited porous substrate is in electrical contact with a cathode current collector and a suitable liquid catholyte. The cathode is, for example, combined with a molten alkali metal anode to form a storage cell. The alkali metal and the catholyte are molten or liquid at operating temperatures of the cell. Methods of storing energy and generating energy using cell having the aluminum-based cathode are provided.

Abstract: An anomalous battery operating detection device, which includes a sensing unit capable of measuring mechanical properties of a battery, coupled to a processor for determining whether anomalous behavior has been detected. These devices measure a mechanical property, identifying a difference in the property, and based on that difference, making a determination of anomalous behavior. Non-mechanical properties may also be utilized when making the determination. Responsive actions can be taken once the anomalous behavior is detected. The battery can be intercalated, and may be a lithium-ion battery cell. Alternatively, the sensing unit may measure strain. In addition, more than one sensing unit may be utilized, or a separate light source may be introduced. The system may be configured to allow the processor to determine the potential for failure before the battery fails.

Abstract: Improved anodes and cells are provided, which enable fast charging rates with enhanced safety due to much reduced probability of metallization of lithium on the anode, preventing dendrite growth and related risks of fire or explosion. Anodes and/or electrolytes have buffering zones for partly reducing and gradually introducing lithium ions into the anode for lithiation, to prevent lithium ion accumulation at the anode electrolyte interface and consequent metallization and dendrite growth. Various anode active materials and combinations, modifications through nanoparticles and a range of coatings which implement the improved anodes are provided.

Abstract: The present specification relates to an anode, a lithium secondary battery including the same, a battery module including the lithium secondary battery, and a method for manufacturing an anode.

Abstract: A battery-system deterioration control device compatible to diversification of applications by appropriately learning a necessary deterioration model for a deterioration control. The battery-system deterioration control device includes a utilization-record-data obtaining block, a learning instruction block, and a learning block. The utilization-record-data obtaining block obtains utilization record data of a battery cell. The learning block updates a data amount of a deterioration model parameter indicating the deterioration state of the battery cell based on the utilization record data, learns the deterioration model parameter, and outputs the learnt result that is a deterioration rate table. The learning instruction block compares the utilization record data and the data amount that is the estimation value, determines the necessity of learning of the deterioration model parameter, and outputs a learning instruction signal to the learning unit.

Abstract: A terminal device and a charge control method are provided by the disclosure. The terminal device includes a first processor, which includes a first communication interface. The first processor receives a firmware transmitted by a second processor through the first communication interface when the first communication interface is open, and reads control instructions recorded in the firmware when the terminal device is coupled to an adapter, to control the adapter to charge the terminal device, wherein when the first processor stores no firmware, the first communication interface is open; a second processor acquires the firmware from a server, and when the first communication interface is open, transmits the firmware by the first communication interface. Therefore, the improved charge method based on the control of the terminal device is more practical and universal.

Abstract: A power storage system of the invention, includes: a power generator; a first storage battery; a second storage battery having smaller capacitance than that of the first storage battery; a first switcher that connects or disconnects the first storage battery to or from a power supply line and a load device; a second switcher that connects or disconnects the second storage battery to or from the power supply line and the load device; a first switching unit that compares a voltage supplied to the load device with first and second predetermined threshold voltages and controls the first switcher according to a result of the comparison; and a second switching unit that compares the voltage supplied to the load device with third and fourth predetermined threshold voltages and controls the second switcher according to a result of the comparison.

Abstract: In certain embodiments, a battery thermal management system includes at least one battery, at least one thermoelectric device in thermal communication with the at least one battery, and a conduit comprising an inlet configured to allow a working fluid to enter and flow into the conduit and into thermal communication with the at least one thermoelectric device. The conduit further comprises an outlet configured to allow the working fluid to exit and flow from the conduit and away from being in thermal communication with the at least one thermoelectric device. The battery thermal management system can further include a first flow control device which directs the working fluid through the inlet of the conduit and a second flow control device which directs the working fluid through the outlet of the conduit. The first flow control device and the second flow control device are each separately operable from one another.

Abstract: A heat sink and power battery system are provided. The heat sink includes a heat dissipation plate and a cover plate. The heat dissipation plate includes a bottom plate and a plurality of fins arranged on the bottom plate in a comb-like pattern. The cover plate is fixedly connected to the heat dissipation plate. The fins of the heat dissipation plate are disposed between the bottom plate and the cover plate, and an air duct is formed among the bottom plate, the fins, and the cover plate.

Abstract: Some embodiments provide a novel method for harnessing the heat generated by one or more components (e.g., a set of IR LEDs) of an A/V recording and communication device in order to manage the temperature of one or more batteries of the A/V recording and communication device. Some aspects of the present embodiments raise the temperature of the battery in a cold weather without requiring any additional electrical power (e.g., without consuming any additional power for heating up the battery). In one aspect of the present embodiments, a thermally conductive sheet is coupled to a printed circuit board to which one or more IR LEDs are coupled. The thermally conductive sheet transfers the waste heat generated by the IR LEDs of the A/V recording and communication device to a rechargeable battery of the device.

Abstract: The stall delay power surge protector is a copper terminal strip that is designed to increase the life of any battery, voltage regulator or starter by acting as a surge protector or a heat sink that dissipates heat only for electrical current. The stall delay power surge protector would be attached and fused into a battery cable that leads to the battery on one end and attached and fused to an electrical wire leading to the voltage regulator or starter on the opposite end of the stall delay power surge protector, thus requiring no direct connection of the stall delay power surge protector to the battery, voltage regulator or starter of any car, boat, motorcycle, riding lawn mower, tractor, truck or RV.

Abstract: Disclosed are methods related to junction ferrite devices having improved insertion loss performance. In some implementations, a method of fabricating a circulator includes providing a grounding plane having a first side and a second side, positioning a magnet on the first side of the grounding plane, and positioning a ferrite-based disk on the second side of the grounding plane, the ferrite-based disk including a metalized layer on a grounding surface such that the metalized layer is in electrical contact with the second side of the grounding plane. In some implementations, a method for fabricating a ferrite disk assembly for a radio-frequency circulator includes forming a ferrite-based disk that includes a ferrite center portion, and forming a metalized layer on a first surface of the disk to improve electrical contact between the first surface of the disk with an external contact surface.

Abstract: A semiconductor structure includes a dielectric waveguide, a driver die, a first transmission electrode, a second transmission electrode, and a receiver die. The driver die is configured to generate a driving signal. The first transmission electrode is located along a first side of the dielectric waveguide and configured to receive the driving signal. The second transmission electrode is located along a second side of the dielectric waveguide and electrically coupled to a transmission ground. The first transmission electrode and the second transmission electrode are mirror images. The receiver die is configured to receive a received signal from the dielectric waveguide.

Abstract: Functionalized microscale 3D devices and methods of making the same. The 3D microdevice can be realized with the combination of top-down (lithographic) and bottom-up (origami-inspired self-assembly) processes. The origami-inspired self-assembly approach combined with a top-down process can realize 3D microscale polyhedral structures with metal/semiconductor materials patterned on dielectric materials. In some embodiments, the functionalized 3D microdevices include resonator-based passive sensors, i.e. split ring resonators (SRRs), on 3D, transparent, free-standing, dielectric media (Al2O3).

Abstract: Nanopillar-based THz metamaterials, such as split ring resonator (SRR) MMs, utilizing displacement current in the dielectric medium between nanopillars that significantly increases energy storage in the MMs, leading to enhanced Q-factor. A metallic nanopillar array is designed in the form of a single gap (C-shape) SRR. Vacuum or dielectric materials of different permittivities are filled between the nanopillars to form nanoscale dielectric gaps. In other embodiments, formation of patterned nanowires using anodic aluminum oxide (AAO) templates with porous structures of different heights resulting from an initial step difference made by etching the aluminum (Al) thin film with a photoresist developer prior to the anodization process are disclosed.

Abstract: The present invention relates to a substrate for supporting an antenna pattern. The substrate includes a porous anodic oxide layer having a plurality of pores formed by anodizing metal. A metallic material is filled in at least a part of the pores.

Abstract: Flexible antennas for harvesting electromagnetic energy are described. The flexible antenna may be a far field antenna and may comprise a flexible substrate, a first metal layer disposed on one side of the flexible substrate, and a second metal layer disposed on an opposite side of the flexible substrate. The first and second metal layers may be connected through one or more vias. The first metal layer may be sized to capture electromagnetic energy at a frequency in an ISM band.

Abstract: Embodiments of the present invention relate to a symmetrical printed radio frequency identification antenna and method of forming a radio frequency identification antenna. In one embodiment, the radio frequency identification antenna comprises a loop element having a plurality of sides. A first conductive element is in electrical communication with the loop element. A second conductive element is in electrical communication with the loop element. The first conductive element includes an integrated circuit pad. The first and second conductive elements extend in opposite directions substantially from a middle portion of a side included in the plurality of sides. The loop, first conductive element, and second conductive element are electrically conductive. The second conductive element includes a quadrilateral portion. The second conductive element has a width that is at least about the length of the side included in the plurality of sides.

Abstract: To provide a substrate for a medical device and a medical device in which the reference potential of a patient circuit can be stabilized, the noise between the patient circuit and a ground-side circuit can be reduced, and the insulation distance between the patient circuit and the ground-side circuit can be sufficiently ensured without using a large-sized electronic component.

Abstract: A multi-band radiating array includes a planar reflector, first radiating elements defining a first column on the planar reflector, second radiating elements defining a second column on the planar reflector alongside the first column, and third radiating elements interspersed between the second radiating elements in the second column. The first radiating elements have a first operating frequency range, the second radiating elements have a second operating frequency range that is lower than the first operating frequency range, and the third radiating elements have a third, narrowband operating frequency range that is higher than the second operating frequency range but lower than the first operating frequency range. Respective capacitors are coupled between elongated arm segments and an elongated stalk of the third radiating elements, and a common mode resonance of the third radiating elements is present in a lower frequency range than the second operating frequency range.

Abstract: A wireless communication device is provided. The wireless communication device includes a millimeter wave antenna comprising a plurality of antenna elements, a radio frequency integrated circuit (RFIC), and a power feeding line, wherein the plurality of antenna elements are dual-type antenna elements configured to excite different polarization modes, and wherein the power feeding line allows a plurality of ports of the RFIC to individually connect to the plurality of dual-type antenna elements to excite the different polarization modes to perform beamforming The wireless communication device and/or electronic device may be diversified according to various embodiments.

Abstract: An antenna system includes a ground which is disposed in a housing and has an end side; a first antenna element which includes a first open-end and a feeding point, and is exposed to an outside of the housing on the side of the first open-end; a second antenna element which includes the feeding point and a second open-end, is disposed between the end side and the first antenna element, and is branched from the first antenna element at a branching point, a section between the branching point and the second open-end being disposed in the housing or being covered with the housing and the first antenna element; and a metal plate which includes a portion connected to the ground and an end portion disposed near the first open-end, a portion of the metal plate near to the end portion being exposed to an outside of the housing.

Abstract: A reflector deployment and pointing mechanism, for deploying and pointing a reflector of an antenna movably mounted on a structure, has a first actuator mounted on the structure, a second actuator mounted on the first actuator, and a third actuator mounted on the second actuator and connected to the reflector. The first or second actuator is the deployment actuator, and, respectively, the second or first, and the third actuators are the pointing actuators and have their axis of rotation generally intersecting a feed oriented point of a signal reflecting surface of the reflector.