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Digital histogram generation for time-resolved measurements with single-photon avalanche diode (SPAD) sensors requires the storage of many timestamp signals. This work presents a mixed-signal time-to-digital converter (TDC) that uses analog storage to achieve an area-efficient design that can be integrated in large SPAD arrays. Fabricated using a 150 nm CMOS process, the prototype occupies an area of only 18.3 µm × 36.5 µm, a notable size reduction compared to conventional designs. The experimental results demonstrated high performance, with an integral nonlinearity (INL) of 0.35/0.14 least significant bit (LSB) and a differential nonlinearity (DNL) of 0.14/−0.12 LSB. In addition, the proposed TDC can support the construction of histograms comprising up to 512 bins, making it an effective solution to accommodate a wide range of resolution requirements. Validated in a point-of-care (PoC) device for fluorescence lifetime measurements, it distinguished between lifetimes of approximately 4.1 ns, 3.6 ns and 80 ns with the Alexa Fluor (AF) 546 and 568 dyes and Quantum Dot (QD) 705, respectively. The analog storage design and area-efficient architecture offer a novel approach to integrating TDCs in SPAD-based systems, with potential applications in medical diagnostics and beyond.

A Point-of-Care system for molecular diagnosis (PoC-MD) is described, combining GaN and CMOS chips. The device is a micro-system for fluorescence measurements, capable of analyzing both intensity and lifetime. It consists of a hybrid micro-structure based on a 32 × 32 matrix addressable GaN microLED array, with square LEDs of 50 µm edge length and 100 µm pitch, with an underneath wire bonded custom chip integrating their drivers and placed face-to-face to an array of 16 × 16 single-photon avalanche diodes (SPADs) CMOS. This approach replaces instrumentation based on lasers, bulky optical components, and discrete electronics with a full hybrid micro-system, enabling measurements on 32 × 32 spots. The reported system is suitable for long lifetime (>10 ns) fluorophores with a limit of detection ~1/4 µM. Proof-of-concept measurements of streptavidin conjugate Qdot™ 605 and Amino PEG Qdot™ 705 are demonstrated, along with the device ability to detect both fluorophores in the same measurement.

MicroLED arrays with the capability of switching each pixel separately with high frequency can serve as structured micro-illumination light engines for applications in sensing, optogenetics, microscopy and many others. We describe a scalable chip process chain for the fabrication of passive-matrix microLED arrays, which were integrated with PCB-based driving electronics. The arrays were produced by deep-etching of conventional planar LED structures on sapphire, followed by filling and planarization steps. The pixel resolution lies in the range of 254 to 2540 pixels-per-inch (ppi), the arrays consist of 32 x 32 pixels. Optical output powers up to 50 µW per pixel were measured. In comparison to CMOS-based approaches, the presented technology is a simplified strategy to produce microLED arrays with high pixel counts.

The recent advances in chip-size microscopy based on optical scanning with spatially resolved nano-illumination light sources are presented. This new straightforward technique takes advantage of the currently achieved miniaturization of LEDs in fully addressable arrays. These nano-LEDs are used to scan the sample with a resolution comparable to the LED sizes, giving rise to chip-sized scanning optical microscopes without mechanical parts or optical accessories. The operation principle and the potential of this new kind of microscope are analyzed through three different implementations of decreasing LED dimensions from 20 µm down to 200 nm.

Recent research into miniaturized illumination sources has prompted the development of alternative microscopy techniques. Although they are still being explored, emerging nano-light-emitting-diode (nano-LED) technologies show promise in approaching the optical resolution limit in a more feasible manner. This work presents the exploration of their capabilities with two different prototypes. In the first version, a resolution of less than 1 µm was shown thanks to a prototype based on an optically downscaled LED using an LED scanning transmission optical microscopy (STOM) technique. This research demonstrates how this technique can be used to improve STOM images by oversampling the acquisition. The second STOM-based microscope was fabricated with a 200 nm GaN LED. This demonstrates the possibilities for the miniaturization of on-chip-based microscopes.

In this two-part article we discuss the difference between a continuous and a discrete approach to trap modeling in the simulation of 3-D NAND Flash memories with polysilicon channel. In Part I we focus on threshold voltage $({\mathrm { V}}_{\mathrm { T}})$ fluctuations induced by traps and show that lower values for the average and rms ${\mathrm { V}}_{\mathrm { T}}$ arise when the discrete nature of traps is accounted for. We explain such differences in terms of a stronger percolation that leads to a lower number of filled traps in the discrete-trap case, and investigate such differences as a function of cell parameters and temperature. Finally, we compare the two approaches showing that a continuous trap model cannot reproduce the correct dependences resulting from a discrete treatment.

In Part II of this article we discuss the impact of a discrete treatment of traps on 3-D NAND Flash random telegraph noise (RTN). A higher RTN results when discrete traps are taken into account, that can only be explained by a stronger influence of the discrete charged traps on the current conduction, leading to more percolation. The effects are then investigated as a function of the cell parameters, showing that a continuous model for traps cannot reproduce the correct dependence.

Wastewater treatment plants receive influent wastewater that is contaminated with bacterial pathogens which may be released into the environment if the plant effluent is inadequately treated. In this study, next-generation sequencing was used to perform a 16S rDNA-based survey of bacterial populations in the influent and effluent from a treatment facility in the North-West Province (SA). In total, 3638 and 3872 effective DNA reads were obtained for the influent and effluent, respectively. Sequence analysis revealed the detection of a diverse bacterial constituency in both the influent and effluent samples. The phyla: Proteobacteria (49.82% and 52.04%), Firmicutes (14.06% and 13.14%) and Actinobacteria (5.00% and 9.99%) were found to be taxonomically abundant in the influent and effluent, respectively. This translated to the detection of biological treatment-, fecal coliform-, and disease-associated bacterial groups that are classified under the following genera: Escherichia spp., Serratia spp., Aeromonas spp., Legionella spp., Pseudomonas spp., Mycobacterium spp., Clostridium spp., Staphylococcus spp. and Streptococcus spp., Comamonas spp., Nitrosomonas spp., Acinetobacter spp., Rhodobacter spp., Paracoccus spp., Hyphomicrobium spp., and Desulfovibrio spp.

This paper presents a TCAD-based methodology to enable Design-Technology Co-Optimization (DTCO) of advanced semiconductor memories. After reviewing the DTCO approach to semiconductor devices scaling, we introduce a multi-stage simulation flow to study the device-to-circuit performance of advanced memory technologies in presence of statistical and process variability. We present a DRAM example to highlight the DTCO enablement for both memory and periphery. Our analysis demonstrates how the evaluation of different possible technology improvements and design combinations can be carried out to maximize the benefits of continuous technology scaling for a given set of manufacturing equipment.

The agriculture of the Republic of Moldova is particularly prone to natural risks, especially droughts. The purposeof this paper is to present the state of sustainable development of the agricultural sector and opportunities forimplementation of the innovative land cultivation technologies. There are a number of socio-economic constraintsfor increasing the productivity in the traditional agricultural systems. In order to meet the growing competition onthe regional markets of agricultural products, modernization of agriculture in the Republic of Moldova is veryimportant. For investigation of the actual state of implementation of the conservative land cultivation technologieswere used specific methods and techniques such as statistical and economic analysis of economic indicators, casestudy approach, semi-structured interviews of agricultural producers. The study is also based on the statisticsreceived from the National Bureau of Statistics and the Ministry of Agriculture and Food Industry of Moldova.Economic analysis confirms that implementation of the No Till technology will reduce essentially the directproduction costs compared to traditional technology. However a more visible effect occurs starting with the 5-6year of the conservative land cultivation technologies’ implementation.

The article deals with the consequences of global climatic changes on the state of Ukrainian Danube region agrolandscapes. The influence of weather climatic conditions on change of water balance of the regional ecological systems was studied by definition of three main indicators: evaporability, deficiency of water consumption and moistening coefficient. Experimental information was given according to supervision of Danube Hydrometeorological Observatory (Izmail, Ukraine). In comparison with the statistics of weather conditions for 1961-1990 and 1991-2000 the climatic situation in 2001-2012 testifies to significant increase in an evaporability (19, 5 %) and deficiency of water consumption of the soil (41, 9 %). As a result some changes of agrolandscapes were noticed in the region, connected with mass emergence of weeds, which are atypical for the region: Ambrosia artemisifolia L. Lactuca tatarica L, Anisantha tectorum Nevski, Cyclachaena Xantifolia L. etc. Due to the high competitive capacity of weed plants, they began to occupy in the cultivated cultural plants a dominant position that led to decrease of fertility of soils and crops. Thus agrolandscapes traditionally created on arable lands became now unstable and are in great need in their arrangement.

This paper focuses on the links between agricultural modernization and sustainable development, looking in particular at the impact of the structural changes over the rural livelihoods. In order to achieve this, there were used the following research methods such as: analysis of the economic indicators, methods of comparative analysis, assessment of the public policies’ impact on the rural development. The agricultural sector in the Republic of Moldova is based on extensive farming and is insufficiently adapted to market economy conditions. There is a growing understanding in the country that the rural economy is not confined to the agricultural sector, but embraces the broad spectrum of needs of all rural people including living standards, economic activities and natural resources. The situation is associated with the major risks related to the structural changes that may affect the countryside and the economy as a whole such as: a) migration and uncontrolled urbanization, b) lack of professional qualifications and adaptability of the population in the rural areas, c) inadequate use of the natural resources. Rural economy, employment issues, natural resource management and also goals and circumstances of the agricultural production have changed considerably. At the same time, academia and civil society are aware that the new paradigm of modernization must begin both with the agricultural technologies and the people. Its novelty is that in the combination of financial, economic and technological policies for agriculture, new components to be introduced, like policies aimed at improving human capital in agriculture and environmental protection. The paper contains conclusions and proposals on modernization of agriculture and diversification of non farm activities in rural areas.

This paper focuses on the links between rural transformations and sustainable livelihoods, looking in particular at the impact of the structural changes over the national economy. In order to achieve this, there were used the following research methods such as: analysis of the economic indicators, methods of comparative analysis, assessment of the public policies’ impact on the rural development. The agri-food sector in the Republic of Moldova is based on extensive farming and is insufficiently adapted to market economy conditions. There is a growing understanding in the country that the rural economy is not confined to the agricultural sector, but embraces the broad spectrum of needs of all rural people including living standards, economic activities and natural resources. The paper contains conclusions and proposals on diversification of agriculture and non farm activities in rural areas.

This paper focuses on the links between changes in the land use and sustainable rural development in the Republic of Moldova. A particular attention is addressed to the analysis of land ownership fragmentation, existing impediments for creation of sustainable agricultural systems based on principles of economic growth, social equity and protection of the environment. The following research methods such as analysis of the impact of public policies in rural areas, including in agriculture, comparative analysis, analysis of annual time series, were used. There were also used qualitative research methods such as: interviews of key stakeholders and focus groups’ interviews. Data for the quantitative analysis were collected from statistical yearbooks of the Republic of Moldova, National Land Cadastre and other available sources. The agricultural sector of the Republic of Moldova after the land reform is characterized by a polarization between large corporate farms and many small and fragmented family farms. The consolidation of land ownerships could become an effective instrument that can address both the problems of land fragmentation, but also the sustainable rural development in a wider context.

The main challenge of the food sector in the Republic of Moldova is to identify specific needs and opportunities for agriculture and rural development throughout food supply chains, and focusing investment in areas where the most impact will be made. The identification and allocation of resources requires analysis of main dimensions of food supply chains, in order to establish links and determine local factors. In small transition economies the diagnosis of the food supply chains, is typically based on limited data and incomplete information. In order to investigate the actual state of food supply chains were used specific methods and techniques: statistical and economic analysis of macro-economic indicators, semi-structured interviews of key stakeholders, analysis of the impact of public policies on the agro-food sector. In the article is analyzed the process of food systems formation and integration at the local and global level. Although it is a small part of the overall agricultural sector, various local food systems are under development in the Republic of Moldova. These systems bring consumers in close contact with farmers and mobilize them to support local farms and sustainable farming practices. While local food systems continue to face many barriers, many of them show considerable potential for growth.