An N/M-Ratio All-Digital Clock Generator with a Pseudo-NMOS Comparator-Based Programmable Divider

A multiplying delay-locked loop (MDLL)-based all-digital clock generator with a programmable N/M-ratio frequency multiplication capability for digital SoC is presented. The proposed digital MDLL provides programmable N/M-ratio frequency multiplication using a new high-speed Pseudo-NMOS comparator-based programmable divider with small area and low power consumption. The proposed MDLL clock generator can also provide a de-skew function by eliminating the phase offset problem caused by the propagation delay of the front divider in conventional N/M MDLL architectures. Fabricated in a 0.13-µm 1.2-V CMOS process, the proposed digital MDLL clock generates fully de-skewed output clock frequencies from 0.3 to 1.137 GHz with programmable N/M ratios of N = 1~32 and M = 1~16. It achieves a measured effective peak-to-peak jitter of 12 ps at 1.0 GHz when N/M = 8/1. It occupies an active area of only 0.034 mm2 and consumes a power of 10.3 mW at 1.0 GHz.

Interfacial Phenomena at the Interface in the System «Carbon Primary Materials-Water Solutions of Surfactants» for Cement Materials

The formation of sustainable concrete is directly relaed to the intensity of the processes occurring at the interface of phases. The study of the surface properties of CNPLUS carbon nanotubes in solutions of various plasticizers was carried out by measuring and calculating adsorption. The applicability of the adsorption value is for forecasting both the efficiency of dispersion and aggregative and sedimentative stability of the obtained dispersion systems. It was stated that two-dimensional pressure arising at the interface of adsorption layers in the dispersive medium with the surfactant Tensafor 2553.2 J/m2 is sufficient to overcome adhesive strength on a small area of the localized contact of carbon nanoparticles CNPLUS, which explains the peptization and stabilization of the particles’ surface. It was established that full stabilization of nanoparticles in the aqueous dispersive medium could be ensured only by means of soap-like surfactants, with the compound potassium naphthalene sulfonate (Tensafor). It ensures formation of the micelle-like structure in coagulation layers that forms a structural and mechanical barrier with the external hydrophilic surface. This leads to the increase in the ultimate tensile strength of the concrete grout specimens by 38%.

Circulation of Selenium in the Environment

In order to function properly, every living organism must have favourable conditions for its operation, i.e. it must be systematically supplied with the necessary nutrients. On the example of selenium (Se), it can be seen how important is the right balance between providing the right amount of it, without exceeding the level above which it is toxic. The amount of Se in soil is closely correlated with its content in the parent rock; therefore, it differs depending on the soil type and may change even in a small area. Considerable dispersion of the element in the soils of Poland is related to their formation, mainly from dump materials of various glaciations. The problem of maintaining the balance between deficiency and excess of Se in the diet of humans and animals is related primarily to the uneven distribution of this element in nature. In this paper, on the basis of scientific literature, the current issues related to the deficiency and excess of Se in the soil and its possible sources are presented. The relationship between the content in the soil and the supply of Se in plants, animals and humans was also shown. The aim of this study was to summarise the state of knowledge on the complexity of Se occurrence in the environment and its importance in the soil-plant-animals-human system.

A method for small-area estimation of population mortality in settings affected by crises

Background Populations affected by crises (armed conflict, food insecurity, natural disasters) are poorly covered by demographic surveillance. As such, crisis-wide estimation of population mortality is extremely challenging, resulting in a lack of evidence to inform humanitarian response and conflict resolution. Methods We describe here a ‘small-area estimation’ method to circumvent these data gaps and quantify both total and excess (i.e. crisis-attributable) death rates and tolls, both overall and for granular geographic (e.g. district) and time (e.g. month) strata. The method is based on analysis of data previously collected by national and humanitarian actors, including ground survey observations of mortality, displacement-adjusted population denominators and datasets of variables that may predict the death rate. We describe the six sequential steps required for the method’s implementation and illustrate its recent application in Somalia, South Sudan and northeast Nigeria, based on a generic set of analysis scripts. Results Descriptive analysis of ground survey data reveals informative patterns, e.g. concerning the contribution of injuries to overall mortality, or household net migration. Despite some data sparsity, for each crisis that we have applied the method to thus far, available predictor data allow the specification of reasonably predictive mixed effects models of crude and under 5 years death rate, validated using cross-validation. Assumptions about values of the predictors in the absence of a crisis provide counterfactual and excess mortality estimates. Conclusions The method enables retrospective estimation of crisis-attributable mortality with considerable geographic and period stratification, and can therefore contribute to better understanding and historical memorialisation of the public health effects of crises. We discuss key limitations and areas for further development.

Effectiveness of selected issues related to used tyre management in Poland

This paper discusses interactions between the generation, collection and recovery of used tyres while considering an indicator of their mass accumulation per area in Poland. Notably, this study aimed to assess selected issues related to used tyre management efficiency from 2008 to 2018 based on European Union and national regulations. Within 11 years, over 5 million Mg of used tyres was introduced into the domestic market—exceeding the amount required for 50 million registered vehicles. It was demonstrated that a significant tyre waste management process involved the recovery of 47% of all tyres, which was almost entirely correlated with the total volume of tyres. Only the growth trend for generated tyres was considered significant, and the rarely used indicator of the accumulation of used tyres per area exhibited an uneven accumulation of used tyres, with the highest amount being 48.06 Mg km−2 in a region with a small area but a significant volume of waste tyres. Therefore, the management of used tyres requires action in the country to optimally increase this form of waste collection while consolidating the development, gathering and processing infrastructure in the context of further minimising environmental pressure and increasing the efficiency of their use by considering the 4R principle.