A tamper-indicating device, the tamper-indicating device including: an elongate structure; a penetrant chamber coupled to the elongate structure; and a physical barrier (or other release mechanism) disposed between the elongate structure and the penetrant chamber; wherein the penetrant chamber is adapted to contain a penetrant material that selectively diffuses into the elongate structure at a predetermined rate when the physical barrier is ruptured (or the other release mechanism is actuated) by a tamper or environmental event; and wherein the penetrant material creates an overt or covert indication of the degree of diffusion into the elongate structure, the degree of diffusion indicating an amount of time since the tamper or environmental event. The tamper-indicating device further includes a substrate coupled to the elongate structure. Optionally, the tamper-indicating device further includes a visible time scale disposed on the substrate substantially adjacent to the elongate structure.

An embodiment provides a method for measuring total chlorine in a solution, including: preparing a thiocarbamate indicator; introducing the thiocarbamate indicator to a solution, wherein the solution contains an amount of monochloramine; adding an additive to the solution, wherein the additive accelerates the reaction rate between the thiocarbamate indicator and monochloramine and causes a change in fluorescence of the solution; and measuring the amount of monochloramine in the solution by measuring an intensity of the fluorescence. Other aspects are described and claimed.

The present invention relates to compositions comprising: a polypeptide, wherein at least a portion of the polypeptide has a coiled coil structure; and a chelate comprising a chelating agent and a metal ion; and wherein the chelate is bound to at least one amino acid of the polypeptide. In a preferred embodiment the polypeptide is a silk fibroin, wherein at least a portion of the silk fibroin has a coiled coil structure.

A gas sensing element includes a gas detection layer including a chemochromic pigment, with modifications towards enhancing shelf-life performance and false detection performance before use. The gas detection layer has an adhesion of greater than or equal to 0.2 N/25 mm. Also described are methods of making the aforedescribed element to attain enhanced shelf-life performance and false detection performance.

An embodiment provides a method for measuring total chlorine in a solution, including: preparing a thiocarbamate indicator; introducing the thiocarbamate indicator to a solution, wherein the solution contains an amount of monochloramine; adding an additive to the solution, wherein the additive accelerates the reaction rate between the thiocarbamate indicator and monochloramine and causes a change in fluorescence of the solution; and measuring the amount of monochloramine in the solution by measuring an intensity of the fluorescence. Other aspects are described and claimed.

Disclosed is a method for predicting corrosion and spontaneous combustion of sulfur-related petrochemical equipment. The method solves the issues in the existing techniques that includes narrow predicting range, high workload in installation and maintenance, and time lag in predicting corrosion and spontaneous combustion inside equipment. The method comprises a step of a dual index system prediction, which includes a step of monitoring a temperature and a step of detecting SO.sub.2 gas generated by spontaneous combustion. The time when spontaneous combustion occurs can be accurately calculated by using a fitted quantitative relationship formula generated by the spontaneous combustion of corrosion products. The method has a low Labor cost. The method has a low labor cost and, does not require on-site gas detection to be carried out by means of manual detection, which both reduces the cost and ensures the detection accuracy.

A gas detection element for detection of a measurement target gas is provided. The gas detection element includes a gas detection layer including a chemochromic pigment; and a spacer. The spacer is permeable to the measurement target gas, is disposed on a first surface of the gas detection layer, and has an area smaller than an area of the gas detection layer.

Described herein are systems and methods for coupling environmental hazard detection and actuation of a wearable chemical sensor at a molecular level. The chemical sensor may be a wearable chemical sensor implemented as a powder, cream, lacquer or other wearable construct. The wearable chemical sensor may detect exposure to various environmental hazards and provide an analog means (e.g., a range of color changes) of indicating the level of environmental hazard exposure.

A gas sensing element includes a gas detection layer including a chemochromic pigment, with modifications towards enhancing shelf-life performance and false detection performance before use. The gas detection layer has an adhesion of greater than or equal to 0.2 N/25 mm. Also described are methods of making the aforedescribed element to attain enhanced shelf-life performance and false detection performance.

A gas detection system includes (1) an output device configured to output data acquired by monitoring a gas sensing element including a gas detection layer including a pigment; and (2) an information processing apparatus configured to process the data output by the output device, wherein the information processing apparatus includes a determining unit configured to determine whether the gas sensing element has detected gas, based on the data, and a display control unit configured to display, on an indication element, information indicating a position of the gas sensing element that has detected the gas or information indicating a status of gas leakage determined based on the data, when the determining unit determines that the gas sensing element has detected the gas.