BERYL AS A CONSTITUENT IN HIGH TENSION INSULATOR PORCELAIN

Two series, one of 9 bodies and one of 6, were prepared, in which flint and feldspar were partially replaced, weight for weight, by beryl. Bars and discs were fired to cone 8 3/4, to 10, or to 10 3/4 and tested for shrinkage, transverse strength, impact strength, heat resistance, absorption of moisture, and dye penetration. The results show that introduced in proper proportions beryl increases the transverse strength, impact strength, heat resistance and dielectric strength. The best results are obtained with the following limits of composition:     

GLASS WOOL AS INSULATOR FOR REFRIGERATION PURPOSES1

A new method has been used to measure the thermal conductivities of insulating materials which consists of the observation of the rate of melting of ice in a vessel insulated with the material under investigation. This is done by noting the change of volume of the mixture of ice and water by means of a graduated glass tube connected to the vessel. Results are given for glass wool of various densities, powdered cork, magnesia asbestos composition, slag wool, Sil-O-Cel powder, cotton waste and sheep's wool. It is also shown that glass wool that can be kept dry is a very superior insulating material.     

TALC AS THE PRINCIPAL BODY INGREDIENT IN VITRIFIED CERAMIC BODIES1

This paper is an attempt to explain the firing behavior of pure talc as well as talc-clay, talc-lime, talc-clay lime, and some other high magnesia mixtures. Phase rule equilibrium diagrams are used. The study applies only to those mixtures where talc is present in amounts greater than 50% of the total composition.     

THE EFFECT OF LEPIDOLITE IN A HIGH TENSION ELECTRICAL PORCELAIN BODY1

Lepidolite is a lithium mica which has had considerable commercial application in glass and enamels. Its use in porcelain has not been tried to any great extent. This work covers the replacement by lepidolite of the feldspar in a high tension electrical porcelain. The results show that changing the RO of the standard body by molecularly replacing K₂O by Li₂O raises the vitrification temperature of the body, but that replacing feldspar directly pound for pound by lepidolite greatly lowers the vitrification temperature of the body. Lepidolite gives porcelains having a fine appearance and extreme whiteness. The most important property noted is an improvement of the bodies containing lepidolite in resistance to thermal shocks. Owing to its higher cost it is unlikely that lepidolite will be used in porcelains except in small proportions with feldspar to produce bodies having special properties. As hitherto the most important applications of lepidolite will doubtless be in glasses and enamels where full benefit can be secured from its fluorine content and low fusion temperature.     

A RAPID METHOD FOR PREPARING A SILICATE ROCK FLUX FOR DEHYDRATION

When time is an important factor in the analysis of silicate rock or clay the following method of treating the flux will be found advantageous. The molten flux is poured into the bore of a steel cylinder that is resting on an iron plate. A tightly fitting plunger is inserted into the bore and rapped smartly with a hammer. The broken flux is swept into a dish where it is dissolved in acid.     

FLUX FOR CHEMICAL ANALYSIS OF FUSED ALUMINA REFRACTORIES1

A mixture of sodium carbonate and borax is suggested as a flux for the chemical analysis of fused alumina refractories. The elimination of boron by several evaporations with methyl alcohol was found to be unnecessary.     

新型纤维缠绕张力控制系统研究

本文针对多轴纤维缠绕机数控系统,提出了一种集成于运动控制器平台上的纤维缠绕张力控制系统的方案。利用运动控制器的剩余通道,采用张力反馈式控制方式和控制器的计算功能完成了对张力的精密闭环控制。研制了以编码器为反馈元件的新型张力测量装置,实现了基于同一个可编程运动控制器的缠绕机运动控制与张力控制的集成。     

A CONE FUSION MUFFLE FURNACE FOR HIGH TEMPERATURE WORK1

A laboratory type muffle furnace in which the muffle (inside dimensions 9 by 6 inches) was built of standard “Refrax” brick and heated by means of two slotted graphite electric resistors, has been in use for over a year in the Research Laboratory of The Carborundum Company at Niagara Falls. Although specifically designed for cone fusion studies, in which work it is very successful, it can be used for other laboratory work especially at high temperatures (up to at least 1600°C)such as small fusions, heat treatment, etc.     

GAS AS FUEL FOR VITREOUS ENAMELING1

The typical furnace described has a burning chamber four feet wide, ten feet long and thirty-four inches high, no muffle being necessary. The furnace is of the intermittent type. All the details of normal production are given together with a resume of the surprisingly low total cost per hour. A comparison of the average hourly production on 24- and 22-hour bases is given. Also several suggestions are made that will materially effect additional economies in the use of gas for vitreous enameling.     

脂肪醇表面张力的改进算法

本文检验并改进了用于脂肪醇表面张力计算的Van der Waals方程式,提出了更简单的计算方程,将C_1—C_(18)脂肪醇的计算值与实验值相比较,总的绝对平均误差为1.4％。     

METHODS USED IN TESTING MASONRY SPECIMENS FOR BENDING,TENSION, AND SHEAR1

Twenty-four walls, 41/2 feet wide, 51/2 feet high, some 8 inches and some 12 inches thick, werr tested for bending alter aging sixty days and six months, respactively. It was shown that aging of lime mortar is essential. Failures in shearing stress were also due to immature mortar. Brick masonry withstands earthquake shocks when mortar is matured by aging. An outline of the more extensive tests is given.