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In this study, an attempt has been made to collect the research that has been done on the construction and design of the H₂O₂ sensor. So far, many efforts have been made to quickly and sensitively determine H₂O₂ concentration based on different analytical principles. In this study, the importance of H₂O₂, its applications in various industries, especially the food industry, and the importance of measuring it with different techniques, especially portable sensors and on-site analysis, have been investigated and studied.

Hydrogen peroxide (H₂O₂) is a very simple molecule in nature, but due to its strong oxidizing and reducing properties, it has been widely used in the pharmaceutical, medical, environmental, mining, textile, paper, food production and chemical industries. Sensitive, rapid and continuous detection of H₂O₂ is of great importance in many systems for product quality control, health care, medical diagnostics, food safety and environmental protection.

Various methods have been developed and applied for the analysis of H₂O₂, such as fluorescence, colorimetry and electrochemistry, among them, the electrochemical technique due to its advantages in simple instrumentation, easy miniaturization, sensitivity and selectivity.

Monitoring the H₂O₂ concentration level is of practical importance for academic and industrial purposes. Edible oils are prone to oxidation during processing and storage, which may adversely affect oil quality and human health. Determination of peroxide value (PV) of edible oils is essential because PV is one of the most common quality parameters for monitoring lipid oxidation and oil quality control. The development of cheap, simple, fast, sensitive and selective H₂O₂ sensors is essential.

Studies are presented which demonstrate that: (1) irradiation of titanium and zinc oxide pigments produces singlet oxygen; (2) irradiation of titanium dioxide pigments in water yields, hydrogen peroxide; and (3) the formation of singlet oxygen and hydrogen peroxide correlates with chalking tendencies of the pigments. These findings, together with the results of quenching studies, are interpreted in terms of a working hypothesis, for the generation of reactive oxidants, which ties together previous work into a unified scheme. The relative chalking rates of anatase and rutile titanium dioxide as well as the improvement of chalk resistance by surface treatment, are discussed within the framework of this scheme. The role of singlet oxygen in the chalking process, the importance of its presence with regard to the control of chalking, and possible mechanisms for its formation are also discussed.

THE rocket motor is a form of jet propulsion which is characterized by independence of the external atmosphere for combustion, relative independence of altitude and flight velocity upon thrust, small frontal area for high thrusts, simple construction and low weight, and high rate of fuel consumption. Its use was greatly developed during the war years and many applications are now familiar to all. Most of the work on rocket missiles, such as the anti‐aircraft barrages, fighter armament, etc., was performed with solid fuel rockets, but liquid fuels were developed by the Germans for the well‐known V.2, for the Me. 163 aircraft, the Henschel glide bomb and various other applications. They concentrated a great deal of effort on this work and considerable technical progress had been made with different systems. Three main systems emerged and these were distinguished by the oxygen bearing fluids they used. The fluids were:

APPLICATION of the so‐called high energy liquid fuels and high energy liquid oxidizers to power plants based on the jet propulsion principle is receiving the increasing interest and attention of rocket propellant chemists and power plant engineers universally. The aspect of substantially increased—as much as 50 per cent— energy per pound of propellant load or per cubic foot of propellant tankage over today's propellants has whetted scientific appetites and justified probing the field of high energy chemicals to determine, as logically and as practically as we can at the present time, the gains, problems, limitations and applications of these higher energy chemicals. The object of this paper is, in a general way, to discuss the subject of chemical rocket propellants in such a way that the following five questions will be, in part at least, answered or recalled to the minds of this audience for additional deliberation.

For complex engineering problems, multidisciplinary design optimization (MDO) techniques use some disciplines that need to be run several times in different modules. In addition, mathematical modeling of a discipline can be improved for each module. The purpose of this paper is to show that multi-modular design optimization (MMO) improves the design performances in comparison with MDO technique for complex systems.

MDO framework and MMO framework are developed to optimum design of a complex system. The nonlinear equality and inequality constrains are considered. The system optimizers included Genetic Algorithm and Sequential Quadratic Programming.

As shown, fewer design variables (optimization variables) are needed at the system level for MMO. Unshared variables are optimized in the related module when shared variables are optimized at the system level. The results of this research show that MMO has lower elapsed times (14 percent) with lower F-count (16 percent).

The monopropellant propulsion upper-stage is selected as a case study. In this paper, the efficient model of the monopropellant propulsion system is proposed. According to the results, the proposed model has acceptable accuracy in mass model (error < 2 percent), performance estimation (error < 6 percent) and geometry estimation (error < 10 percent).

The monopropellant propulsion system is broken down into the three important modules including propellant tank (tank and propellant), pressurized feeding (tank and gas) and thruster (catalyst, nozzle and catalysts bed) when chemical decomposition, aerothermodynamics, mass and configuration, catalyst and structure have been considered as the disciplines. The both MMO and MDO frameworks are developed for the monopropellant propulsion system.

FUTURE FOR MOLYBDATES. Results reported from the Battelle Memorial Institute suggest that molybdates may have a future as anti‐corrosive pigments. Two advantages over conventional materials such as red lead, zinc chromate and iron oxide are their non‐toxicity and white colour. They are, however, more expensive, especially when compared on a weight basis, but the difference in cost is less marked when compared on a volume basis, the molybdates being lower in density than the conventional pigments.

In antitrust class-action litigation, courts are increasingly unlikely to accept the presumption that all class members were harmed by price-fixing among a group of firms or by exclusionary behavior by a single firm. Econometric methods typically applied in antitrust and other settings estimate the average effect of the challenged conduct, but do not inform impact for individual class members. We present classwide econometric methods and statistical tests for detecting the existence (or lack thereof) of common impact and determining what proportion (if any) of the proposed class suffered injury in many class actions. We conclude that econometric tools can meaningfully inform the legal process, even when courts demand proof of common impact.

The attention of the Board is drawn from time to time to advertisements in trade papers and circulars of preservative substances sold under proprietary names. These consist for the most part of well‐known preservatives or mixtures of preservatives which are easily detected by the analyst in food substances to which they have been added. A new preservative, sold under the name of “Mystin,” for preserving milk and cream has recently been advertised as possessing the advantage that its presence cannot be detected by analysis. Samples have been sent to farmers and milk vendors accompanied by a trade circular from which the following extracts have been taken:—

This is an attempt to understand the processes which take place during the dispersion of organic pigments in PVC‐based application media. It transpired that when the pigments are incorporated using a two‐roller mill, the crucial stage is the mechanical disintegration of the agglomerates. The results were achieved in a temperature range of 110 to 180°C, and were independent of the plasticiser content. Several variables were considered, and due allowances were made.

A corrosion inhibitor may be defined as a material which, when added in small amounts to a corrosive product or environment affecting a metal, effectively decreases its corrosion rate or perhaps prevents it altogether.