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Despite service downgrades' undisputed practical relevance, service downgrades (e.g. customers shifting the price tier downward) have received surprisingly little attention from scholars. Previous studies have focussed on either the public policy issue of tiered pricing or optimal pricing by the service provider. Only a few studies have examined why customers shift across different price tiers and how such activities indicate their future behaviour.

Based on customer data collected from a major telecommunications company, the authors use a logistic regression model to investigate how two service modification levers (i.e. transaction- and relationship-level factors) influence the likelihood of service downgrade. The authors apply a survival model to study how service downgrades affect customer churn.

Transaction-level factors such as service usage (e.g. the frequency and recency of underuse experiences) are positively associated with the likelihood of a downgrade. However, relationship-level factors (e.g. relationship duration and customer status) are negatively associated with the likelihood of downgrades. Customers engaging in downgrades are more likely to churn in the future.

The authors focus on downgrade behaviour, which can be perceived as customers' choice to move down the price tier, which likely ruins the service provider's performance. The authors conceptualise two fundamental driving forces behind a service downgrade: the misfits between the actual usage and the service plan chosen and the deteriorating relationships. The authors' empirical findings on the factors influencing downgrades provide insights for service providers seeking to prevent such behaviour.

Explores damp in the context of historic buildings, explaining why these structures require an individualistic approach. Outlines historic building materials and construction and the history of damp treatments. Discusses the causes of damp related damage, concentrating on direct penetration of rainwater, rising damp, condensation and hydroscopic salts. Details the principles of historic pointing and rendering, and the differences in modern techniques, touching on preventatives such as leadwork, water repellents and consolidants. Concludes that the primary consideration when working on any aspect of historic building work is that any clash between building conservation and human comfort ought to favour the building.

The following report was brought up by Dr. P. Brouardel, Dean of the Faculty of Medicine of Paris, President of the Commission, and was submitted for the approval of the Congress:

To identify the causes to the variation of shade of coloured acrylic sheets from one batch to another and to propose solution to alleviate such a phenomenon.

A number of analytical techniques, including spectrophotometric measurement, evaluation of dispersion stability, pigment particle size analysis, scanning electron microscopy and transmission electron microscopy, were employed to assess the degree of colour shade variation, the degree of dispersion and nature of the particles within the acrylic sheet formulations and the acrylic sheet products.

It was found that the variation of shade of the coloured acrylic sheets from one batch to another was mainly caused by the lack of dispersion stability of the pigment particles concerned over time.

The investigation found solutions to the variation of shade of the coloured acrylic sheets from one batch to another.

Colour and colour consistency are a key attribute of the coloured acrylic sheets. Although not frequently encountered, such imperfections were undesirable. The investigation identified the causes to such imperfections and found a way to eliminate such imperfections.

The purpose of this paper is to attempt to use two industrial wastes; waste foundry sands (WFS) and molasses (M) along with lime (L) to improve the strength characteristics of clayey soil.

In the first part of the study, the optimum percentages of materials (WFS, molasses, lime) have been found out by conducting differential free swell (DFS) and consistency limit tests on clayey soil by adding various admixtures. The second and third part of the study investigates the compaction behaviour and unconfined compressive strength (UCS) of clayey soil on addition of optimum amount of various materials alone and in combination with each other. Finally, the micro-structural behaviour of addition of optimum percentages of lime, WFS and molasses using Scanning electron microscopic technique has been discussed.

The laboratory results revealed that the addition of optimum content of lime along with WFS and molasses reduced DFS and plasticity index and increased maximum dry density and UCS values. The microstructural behaviour showed that the presence of lime and molasses filled the voids present in the soil and the addition of WFS helped in providing compact structure, thus improving the strength characteristics.

The study will be helpful in designing low-cost pavement designs for rural roads.

The adverse effect of waste materials on environment may be solved by using them in improving the strength characteristics of clayey soils, thereby providing healthy environment to living beings.

The study will help to provide low-cost methods to improve strength characteristics of clayey soil along with the use of waste materials; the disposal of whose is a challenging task.

This paper aims to assess the effects of chemically accelerated leaching on the physical and mechanical properties of aerial lime–cement mortars (LCMs).

Two aerial LCMs, differencing mainly in their calcium hydroxide content, were degraded by the use of an ammonium nitrate solution as a leaching agent. The leaching effects were studied by evaluating the rate of change in physical (sorptivity and mass loss) and mechanical (flexural and compressive strength) characteristics of aerial LCMs. To quantify the evolution and kinetics of degradation, the leached depth was then characterized at different levels of degradation by means of a phenolphthalein solution.

The experimental results showed that the dissolution of binder decreases the mass, alkalinity and strength of aerial LCMs but increases their sorptivity. A linear relationship was derived by plotting the values of leached depth against the square root of immersion time in an aggressive solution. It was found that the leached depth followed diffusion-controlled kinetics.

It was found that the global loss of compressive strength of aerial LCMs because of complete dissolution of calcium hydroxide can reach up to 80 per cent.

Efflorescence formation is very common in cement-based materials. In the case of mortar, efflorescence is more studied when only Portland cement is used as a binder. However, the repair of historical heritage, as well as the construction system of some countries, usually uses mortars composed of hydrated lime and Portland cement. This study aims to determine the influence of the hydrated lime content on the incidence of efflorescence in mortars.

Mortars with 0%, 50%, and 100% lime/cement ratio were studied, using three different methods to accelerate efflorescence formation. The surface area of mortars affected by efflorescence was quantified by analysis using image software. Also, analysis of mercury intrusion porosity test, flexural tensile, compressive strength, absorption of water by capillarity, porosity, XRD and TGA was performed.

More efflorescence in mortars with a higher amount of lime in their composition was observed. The results show that the increase in the lime content reduces the flexural tensile and the compressive strength and increased the absorption of water by capillarity and the porosity of the mortars. The material formed by the efflorescence was calcium carbonate, proven by microstructural tests.

The results of greater efflorescence formation in mortars with lime are important to alert users who apply this type of material. Some type of protection must be done more rigorously for lime-cement mortars, especially concerning contact with water, since efflorescence tends to be faster for this type of material.

A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions.

A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions. The structures of the intermediate and final products were characterized by FT-IR (Fourier transform infrared spectroscopy analysis), ¹H-NMR (proton nuclear magnetic resonance spectroscopy) methods. The thermal performance of surfactants was analyzed using thermogravimetric analysis (TGA). The thermogravimetric results showed that the sulfate-based Gemini surfactants had good heat resistance (the thermal decomposition temperature of which was in the range of 140∼170?). The Krafft point, surface tension, foaming, Hydrophile–Lipophile Balance Number (HLB), emulsifying, wetting, and lime-soap dispersing performance were measured by visual observation, hanging drop method, aqueous surfactant solution method and Borghetti–Bergman method, respectively. The results have shown that all the sulfate-based Gemini surfactants had good water solubility and lime-soap dispersing ability. When spacer group was -(CH2)2-, with the increase of the carbon chain length from C12 to C14, the micellar concentration critical micelle concentration and surface tension (CMC) gradually increased from 8.25 × 10^–4 mol/L to 8.75 × 10^–4 mol/L and 27.5 mN/m to 30.9 mN/m, respectively. Also, the sulfate-based Gemini surfactants with the different length of the spacer group had a different effect on their performance on foaming properties and foam properties, HLB and emulsifying ability and wetting ability.

In view of the important role of the spacer group and the general use of anionic surfactants in oil fields, this article considers the preparation of a series of sulfate-based Gemini surfactants by changing the spacer group and the chain length of the hydrophobic group and evaluating their surface activity, and finally its Kraffi, on the foam properties, HLB value, emulsifying performance, lime soap dispersing ability etc.

Sulfate-based Gemini surfactants have broad application prospects in the fields of oil and gas exploitation, environmental protection, chemistry and daily chemical industry and so on.

Examines early time‐based ornamental plasterwork in the United Kingdom. Discusses the origins, methods, supporting structures, original finish and repairs and problems of this plasterwork. Concludes that plasterwork can be maintained no matter what condition it is in, so \ill\ action should be centred on helping later conservation by, for example, propping and padding vulnerable plasterwork.