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Nineteen children in every hundred study chemistry to Ordinary Level GCE, and eighty per cent then drop the subject. Judging by current textbooks and examination syllabuses, these children will have no general understanding of modern chemistry. The author puts forward some suggestions for modernising chemistry curricula.

This paper aims to investigate atoms type and channel roughness effects on fluid behavior in nanochannel.

The results of mechanical properties of these structures are reported in this work by using molecular dynamics method.

The results show that nanochannel roughness is a limiting factor in flowing fluid in nanochannel. Moreover, fluids with less atomic weight have more free movement in ideal and non-ideal nanochannels.

For the study of mechanical properties of fluid/nanochannel system, the authors calculated parameters such as potential energy, density, temperature and velocity profiles of simulated fluids.

PERHAPS the most remarkable example in the history of science of classification employed as an engine of discovery, is that afforded by Mendeléeff's classification of the chemical elements, according to their atomic weights, resulting in the formulation of what is known as the Periodic Law.

WAR is not over as we write on the threshold of May, but at any time it may be—so far as Europe is concerned; there can, however, be no settled peace, even in Europe for many months; and any rejoicings which occur before the defeat of Japan would be ironical. It is true the air is fuller than ever of plans and projects not a little mixed with doubts and questions. This is so for librarians as for others. The Library Association syllabus is a main object of discussion and the Editor of the L.A. Record did well to devote several pages of last month's issue to making and answering the sort of questions that are current. There is still the doubt in our mind as to the possibility of getting a library teaching service in working which can affect the first examinations of 1946. The London University School shows as yet no sign of movement and it was there, we assumed, that the would‐be directors of library schools in technical colleges were to be “refreshed.” The technical schools or the Library Association have not advertised for tutors. Meanwhile, and possibly prematurely, the L.A. has written to library authorities asking them to adopt and facilitate the training scheme for the service‐men and women by giving them leave to attend whole‐time schools and, where necessary, to aid them financially. We do not know the results but it is clear that such a suggestion can be considered by a local council only in connexion with schemes as a whole of our and other professional bodies. For the time being it would be well for the present teaching activities to be continued. The new syllabus adds to the demands on students; it does not otherwise alter them.

THE EXTERNAL EXAMINATION is regarded by the majority of students — and many teachers too — as an extremely unfair method of assessing a student's ability to proceed to the next stage of a course. Let it first be said that examinations as they are at present, whether set internally or externally, are not the best possible method for assessing a student's ability; it is possible that they are the best method we have available, since as yet there is no acceptable alternative. For a student's career to depend on a three‐hour examination shows that we have not progressed far in the educational field. There is enormous scope for improvement in this direction; but this is another matter.

The purpose of this paper is to highlight some of the apps currently available that can assist library personnel in reference and information services.

Initially, 101 apps were identified as possible options for reference and information services. Through various evaluation methods, the list was reduced to 25 apps. Apps were excluded due to cost, function, reviews, currency and usability. Other apps were merely excluded due to time and length concerns of the publication.

Overall, the apps included could be utilized by library staff in reference and information service, though not all are ideal in all library settings due to the requirement of subscriptions and user audiences.

While there have been in recent years quite a few articles and books published on apps for librarians, there is very little published on how exactly librarians can use apps to answer reference questions and assist patrons. This article does not attempt to answer the greater question of app application in reference services, but does attempt to identify and evaluate apps that could be used in those instances. With more research and tablet and app training, librarians can begin to more effectively utilize apps at the service desk.

The purpose of this study is the influence of various combinations of metal sulfides on the tribological performance of brake pads.

Three brake pads were prepared using the possible combination of any two of the solid lubricants from Bismuth trisulfide (Bi₂S₃); Tin disulfide (SnS₂) and Antimony trisulfide (Sb₂S₃) are chosen and blended with molybdenum disulfide and graphite. The tribological performance was compared with the brake pad containing aftermarket sulfide mixture. The tribological performance parameters such as performance coefficient of friction, fade percent, recovery percent, wear thickness loss, time is taken to reach the maximum temperature and fluctuation of friction were investigated using Chase tribometer adopting IS 2742 Part-4 (1994) test procedure.

The friction stability of the brake pad with 4Wt% of MoS₂, Bi₂S₃ and SnS₂ was observed to be better, but it showed poor wear performance and aggressive towards the rotor, whereas the brake pad contained 4Wt% of MoS₂, Bi₂S₃ and Sb₂S₃ exhibited improved wear performance.

This paper explains the influence of the combination of multiple metal sulfide in the tribological performance of the copper-free brake friction composite.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0249/

Aluminium is the most proficiently and commonly used metal due to its desirable physical, chemical and mechanical properties. When Aluminium reinforced with hard ceramic particles, shows increased strength and good corrosion resistant and wear resistant qualities. In the present investigation, A390 + X vol. % Zro₂ (X = 5, 10 and 15) composites have been fabricated through P/M technique.

After that the microstructural properties are tested by scanning electron microscope (SEM) analysis wear test is performed using pin-on-disc machine.

The wear conditions of applied load 30N and sliding velocity 1 m/s and track distance 1000m was followed. A390 + 15% Zro₂ of surface of the composites unveiled greater hardness when compared with A390 alloy.

A390 + 15% Zro₂ exhibited superior wear resistance than that of the matrix alloy. Thus the material proves as an excellent solution for applications that requires high wear resistance.

The construction industries at present are focusing on designing sustainable concrete with less carbon footprint. Considering this aspect, a Fibre-Reinforced Geopolymer Concrete (FGC) was developed with 8 and 10 molarities (M). At elevated temperatures, concrete experiences deterioration of its mechanical properties which is in some cases associated with spalling, leading to the building collapse.

In this study, six geopolymer-based mix proportions are prepared with crimped steel fibre (SF), polypropylene fibre (PF), basalt fibre (BF), a hybrid mixture consisting of (SF + PF), a hybrid mixture with (SF + BF), and a reference specimen (without fibres). After temperature exposure, ultrasonic pulse velocity, physical characteristics of damaged concrete, loss of compressive strength (CS), split tensile strength (TS), and flexural strength (FS) of concrete are assessed. A polynomial relationship is developed between residual strength properties of concrete, and it showed a good agreement.

The test results concluded that concrete with BF showed a lower loss in CS after 925 °C (i.e. 60 min of heating) temperature exposure. In the case of TS, and FS, the concrete with SF had lesser loss in strength. After 986 °C and 1029 °C exposure, concrete with the hybrid combination (SF + BF) showed lower strength deterioration in CS, TS, and FS as compared to concrete with PF and SF + PF. The rate of reduction in strength is similar to that of GC-BF in CS, GC-SF in TS and FS.

Performance evaluation under fire exposure is necessary for FGC. In this study, we provided the mechanical behaviour and physical properties of SF, PF, and BF-based geopolymer concrete exposed to high temperatures, which were evaluated according to ISO standards. In addition, micro-structural behaviour and linear polynomials are observed.

This paper aims to evaluate the inhibitive potential of borage flowers’ aqueous extract (BFAE), Borago officinalis L., against the corrosion of mild steel in 1.0 M phosphoric acid.

Evaluation was carried out by chemical hydrogen evolution (HE), mass loss (ML) and electrochemical potentiodynamic polarization (PDP) measurements. SEM-EDX analysis also was used to confirm the existence of the adsorbed film.

It was found that the inhibition efficiency of BFAE increases with the increase in its concentration, but decreases with the increase in temperature. The potentiodynamic polarization curves indicated that BFAE acts as a mixed-type inhibitor with a predominantly anodic action. The adsorption of BFAE on mild steel surface was found to obey Langmuir and thermodynamic-kinetic adsorption isotherms by forming a thin film on the metal surface. SEM-EDX analysis confirms the corrosion inhibition ability of BFEA in 1.0 M H₃PO₄ by forming a thin film on mild steel surface. In this study, the inhibitive action of BFAE components is discussed on the basis of the physical adsorption mechanism. The same results were obtained for both the freshly prepared extract and the one that kept in a refrigerator for one year.

This paper indicates that BFAE can act as a good inhibitor for the corrosion of mild steel in 1.0 M H₃PO₄ even after one year of preparation.