Search

The purpose of the presented research was to determine the suitability of using ultrasonic testing (UT) to inspect heterogeneous, from a material point of view, welded joints on the example of the joints of a ferritic steel element with elements made of an austenitic steel. The echo technique with transverse (SEK) and longitudinal wave heads (SEL) addressed this issue. Due to the widespread use of 13CrMo4-5 and X2CrNiMo17-12-2 steel grades in the energy industry, they were selected as the test materials for the study. The objects of the presented research were welded joint specimens with thicknesses of 8, 12, and 16 mm and dimensions of 300 × 300 mm, made using the 135 metal active gas (MAG) process with the use of the Lincoln 309LSi wire—a ferritic–austenitic filler material. The stages of the research task were (1) making distance–amplitude curve (DAC) patterns from the test materials; (2) preparation of specimens of welded joints with artificial discontinuities in the form of through-holes; (3) performing UT tests on welded joints with artificial discontinuities using heads with 60° and 70° angles for the transverse wave and angle heads for longitudinal waves with similar beam insertion angles; (4) selection, by radiographic testing (RT), of welded joint specimens with natural discontinuities in the form of a lack of sidewall fusion; (5) performing UT tests on welded joints with natural discontinuities, using heads as welded joints with artificial discontinuities. It was found that (1) the highest sensitivity of discontinuity detection was obtained by performing tests on the ferritic steel side, which is due to the lower attenuation of the ultrasonic wave propagating in ferritic steel compared to austenitic steel; (2) the best detection of discontinuities could be obtained using a longitudinal ultrasonic wave; (3) there is a relationship between the thickness of the welded elements, the angle of the ultrasonic beam introduction, and the effectiveness of discontinuity detection. [ABSTRACT FROM AUTHOR]

Here we present the new experimental stations devoted to the studies of matter under extreme conditions at the X-ray absorption beamlines BM23 and ID24-DCM that were recently refurbished within the ESRF – Extremely Brilliant Source (EBS) upgrade program. In comparison with the stations before the EBS upgrade, they exhibit outstanding performances in terms of sample positioning capabilities, acceptance of multi-detection systems and complex sample environments. In addition, significant improvements regarding the photon flux and focusing capabilities down to the submicron size have been achieved. These stations are now coupled with the new ESRF double crystal monochromators that exhibit an exceptional beam position and energy stability and that permit quick micro-EXAFS measurements down to one EXAFS/second, and hyperspectral EXAFS mapping. In this contribution, we discuss the choices regarding the sample and detector stages and illustrate the potential of the new setups for extreme conditions studies based on selected preliminary results. [ABSTRACT FROM AUTHOR]

The Lanzhou Heavy Ion Research Facility (LIRF) is the largest heavy ion research facility in China, providing a substantial volume of experimental data for fundamental research in nuclear physics. The Topmetal-CEE is a pixel readout chip specifically designed for tracking detectors. Within the Topmetal-CEE framework, the front-end amplifier and comparator necessitate precisely adjustable bias voltages. Hence, in this paper, a 14-bit resolution DAC with an R-2R resistor network structure is designed, along with an amplifier featuring high driving capabilities as the DAC driver, thus preventing potential impedance issues when driving large pixel arrays. Test results demonstrate that the DAC module, operating under a 3.3 V supply voltage, can consistently output voltages ranging from 0 to 1.8 V. Furthermore, the differential non-linearity error is less than 1.07 LSB, and the integral non-linearity error is less than 1.57 LSB. [ABSTRACT FROM AUTHOR]

This work presents a rad-hard 12-bit 3 MS/s resistor string DAC for space applications. The converter has been developed using rad-hardened techniques both at architecture and layout levels starting from a conventional topology. The design considers the different effects of the radiation that could damage the circuits in space environments. The DAC has been developed and integrated a standard CMOS 0.13 μm technology by IHP, using RHBD techniques. Low Earth Orbit (LEO) requires a TID value of around 100 krad (Si), according to the expected length of the mission. The temperature range is between −55 °C and 125 °C. The DAC power budget is similar to that of terrestrial applications. The measured INL (Integral Non-Linearity) and DNL (Differential Non-Linearity) are better than 0.2 LSB, while the ENOB (Effective Number Of Bits) at a 3 MS/s clock exceeds 9.7 bits while loading a 10 pF capacitor. The DAC has been characterized under radiation, showing a fluctuation in the analog output lower than 2 LSB (mainly due to measurement uncertainty) up to 500 krad (Si). Power consumption shows a negligible increase, too. A 10-bit version of the same DAC as the downscaled 12-bit one has been developed as well.

Undruggable targets typically refer to a class of therapeutic targets that are difficult to target through conventional methods or have not yet been targeted, but are of great clinical significance. According to statistics, over 80% of disease-related pathogenic proteins cannot be targeted by current conventional treatment methods. In recent years, with the advancement of basic research and new technologies, the development of various new technologies and mechanisms has brought new perspectives to overcome challenging drug targets. Among them, targeted protein degradation technology is a breakthrough drug development strategy for challenging drug targets. This technology can specifically identify target proteins and directly degrade pathogenic target proteins by utilizing the inherent protein degradation pathways within cells. This new form of drug development includes various types such as proteolysis targeting chimera (PROTAC), molecular glue, lysosome-targeting Chimaera (LYTAC), autophagosome-tethering compound (ATTEC), autophagy-targeting chimera (AUTAC), autophagy-targeting chimera (AUTOTAC), degrader-antibody conjugate (DAC). This article systematically summarizes the application of targeted protein degradation technology in the development of degraders for challenging drug targets. Finally, the article looks forward to the future development direction and application prospects of targeted protein degradation technology. [ABSTRACT FROM AUTHOR]

This work presents a rad-hard 12-bit 3 MS/s resistor string DAC for space applications. The converter has been developed using rad-hardened techniques both at architecture and layout levels starting from a conventional topology. The design considers the different effects of the radiation that could damage the circuits in space environments. The DAC has been developed and integrated a standard CMOS 0.13 μm technology by IHP, using RHBD techniques. Low Earth Orbit (LEO) requires a TID value of around 100 krad (Si), according to the expected length of the mission. The temperature range is between −55 °C and 125 °C. The DAC power budget is similar to that of terrestrial applications. The measured INL (Integral Non-Linearity) and DNL (Differential Non-Linearity) are better than 0.2 LSB, while the ENOB (Effective Number Of Bits) at a 3 MS/s clock exceeds 9.7 bits while loading a 10 pF capacitor. The DAC has been characterized under radiation, showing a fluctuation in the analog output lower than 2 LSB (mainly due to measurement uncertainty) up to 500 krad (Si). Power consumption shows a negligible increase, too. A 10-bit version of the same DAC as the downscaled 12-bit one has been developed as well. [ABSTRACT FROM AUTHOR]

The thermometer digital-to-analog converter (DAC) is a distinctive architecture that plays a vital role in converting digital data into corresponding analog signals, the thermometer DAC employs a resistor network where each bit of the digital input corresponds to a unique resistor. It has notable drawbacks that need careful consideration. As the resolution of the DAC increases, the number of required current sources grows exponentially, leading to complex and demanding circuitry. This can escalate power consumption and occupy significant chip area, which is a critical concern in integrated circuit design. Furthermore, the current mismatch between the multiple current sources. Therefore, integrating memristors into DACs paves the way for more compact and efficient designs, reducing system complexity and enhancing reliability. The Voltage ThrEshold Adaptive Memristor (VTEAM) model of memristor is validated by using Virtuoso. In addition, a digital-to-analog converter based on memristor technology is implemented, taking advantage of the memristor's compact size, minimal power usage, and a voltage threshold that is relatively low. The DAC design being proposed is based on a core DAC cell that consists of two memristors connected in opposing orientations. [ABSTRACT FROM AUTHOR]

We investigate the potential to reduce costs and greenhouse gas emissions of the utilization of direct air capture of CO2 (DAC) for the production of algal biofuel. We examine four integrated designs for a DAC system comprised of solid amine monolith adsorbents delivering CO2 at the required level for algae cultivation with a photobioreactor (PBR)-based fuel production facility. We show that the integration of DAC with this biofuel production facility provides cost and greenhouse gas emissions benefits. Heat integration decreases operating expenses by reducing energy demand for heating requirements. Mass integration, utilizing flue gas CO2 as a carbon source for the PBRs, decreases the DAC system scale, resulting in both capital and operating cost savings. The most advantageous option depends on the interplay of heat and mass integration while matching the diurnal rhythm of algal growth with the inherently steady pace and energy requirements of the DAC system and fuel production. For these technologies, the DAC-PBR mass and energy integration provides an 18 % cost reduction and a 50 % reduction in greenhouse gas emissions for the current state of the technology.

Summary: Direct air capture (DAC) is a promising carbon dioxide removal technology, but its effectiveness hinges on access to cheap, low-carbon energy. Here, we present a spatial techno-economic and environmental assessment of the coupling of solid sorbent DAC with different energy sources. We found that the most cost- and energy-efficient option is to couple DAC with thermal power plants, e.g., nuclear and natural gas combined cycle with carbon capture. These two options have a gross levelized cost of DAC (LCODgross) starting at $246–$503 and $314–$557 per tCO2, respectively, for different regions. For renewable energy and energy storage options, regions with good solar irradiation can achieve low LCODgross, at $319 per tCO2 when utilizing concentrated solar power, whereas regions with low solar irradiation are unsuitable for this option due to the high cost and large land requirement. Achieving an LCODgross of ≤$200 per tCO2 would require significant improvements in the current technology. Science for society: Cost-effective transition pathways to keep global temperature rise below 2°C require billions of tons of CO2 removal from the atmosphere annually. Direct air capture (DAC) offers advantages like permanent storage of CO2 with low land use but it is energy-intensive. Thus, sustainable and cost-effective large-scale DAC deployment needs optimal site identification for cheap, low-carbon energy and regional co-benefit maximization. This study presents a global assessment of DAC energy supply options, including conventional and renewable energy sources, considering region-specific factors. Our analysis identifies the most suitable energy supply options for different regions, assessed based on techno-economic and environmental performance and potential co-benefits. The results help provide a foundation of evidence that will be essential for developing business models, strategies, and policies for the sustainable and cost-effective large-scale deployment of DAC systems.

The creation of an 8-bit SAR ADC with a 0.8V and 5V input voltage is discussed in the publication. Cadence Virtuoso software was used to implement the design, which made use of both 180nm and 90nm technology. The comparator block, which was created using Verilog code and required to operate properly, was the main emphasis of the design. Since the comparator is the block that uses the most power overall, optimising it took up a sizable chunk of the design process. The DAC sub-block was implemented using an MDAC network to increase the ADC's accuracy. The ADC was driven by asynchronous control logic, which was implemented using Verilog code and did not require a clock signal. [ABSTRACT FROM AUTHOR]

The purpose of the presented research was to determine the suitability of using ultrasonic testing (UT) to inspect heterogeneous, from a material point of view, welded joints on the example of the joints of a ferritic steel element with elements made of an austenitic steel. The echo technique with transverse (SEK) and longitudinal wave heads (SEL) addressed this issue. Due to the widespread use of 13CrMo4-5 and X2CrNiMo17-12-2 steel grades in the energy industry, they were selected as the test materials for the study. The objects of the presented research were welded joint specimens with thicknesses of 8, 12, and 16 mm and dimensions of 300 × 300 mm, made using the 135 metal active gas (MAG) process with the use of the Lincoln 309LSi wire—a ferritic–austenitic filler material. The stages of the research task were (1) making distance–amplitude curve (DAC) patterns from the test materials; (2) preparation of specimens of welded joints with artificial discontinuities in the form of through-holes; (3) performing UT tests on welded joints with artificial discontinuities using heads with 60° and 70° angles for the transverse wave and angle heads for longitudinal waves with similar beam insertion angles; (4) selection, by radiographic testing (RT), of welded joint specimens with natural discontinuities in the form of a lack of sidewall fusion; (5) performing UT tests on welded joints with natural discontinuities, using heads as welded joints with artificial discontinuities. It was found that (1) the highest sensitivity of discontinuity detection was obtained by performing tests on the ferritic steel side, which is due to the lower attenuation of the ultrasonic wave propagating in ferritic steel compared to austenitic steel; (2) the best detection of discontinuities could be obtained using a longitudinal ultrasonic wave; (3) there is a relationship between the thickness of the welded elements, the angle of the ultrasonic beam introduction, and the effectiveness of discontinuity detection.

Currently, cloud storage servers are controlled by a third-party administrator. This semi-trusted approach gives rise to security concerns. Therefore, in cloud computing, some protocols use a key manager to encrypt the user's private data before uploading the data to the cloud. However, the security concerns that arise from the use of a key manager are not yet solved. In this respect, in this paper, a provably secure user cloud data access control protocol (DAC) is proposed based on existing cloud storage. Empirical tests confirm that the proposed approach is highly secure against adaptive selective ciphertext attacks and has excellent resistance to message attacks. A comprehensive performance evaluation, including time measurements, is conducted and the protocol is compared to other protocols, revealing the efficient file upload and download processes of the proposed approach. The results demonstrate the protocol's strong security, practicality, and operational efficiency. [ABSTRACT FROM AUTHOR]

This article reports a two-stage differential structure power amplifier based on a 130 nm SiGe process operating at 77 GHz. By introducing a tunable capacitor for amplitude and phase balance at the center tap of the secondary coil of the traditional Marchand balun, the balun achieves amplitude imbalance less than 0.5 dB and phase imbalance less than 1 degree within the operating frequency range of 70–85 GHz, which enables the power amplifier to exhibit comparable output power over a wide operating frequency band. The power amplifier, based on a designed 3-bit digital analog convertor (DAC)-controlled base bias current source, exhibits small signal gain fluctuation of less than 5 dB and saturation output power fluctuation of less than 2 dB near the 80 GHz frequency point when the ambient temperature varies in the range of −40 °C to 125 °C. Benefiting from the aforementioned design, the tested single-path differential power amplifier exhibits a small signal gain exceeding 16 dB, a saturation output power exceeding 18 dBm, and a peak saturation output power of 19.1 dBm in the frequency band of 70–85 GHz. [ABSTRACT FROM AUTHOR]

Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called “low-temperature” DAC process, which might be more advantageous for Germany than the “high-temperature” one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167–353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40% of the city of Cologne‘s water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125–138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161–176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.

While various methods of direct air capture (DAC) technology have been implemented, its widespread effectiveness hinges on achieving optimal design and process improvements, largely owing to the high energy costs involved. Literatures reports a substantial heat demand for high-temperature aqueous solutions DAC (HT DAC), ranging from 1420 to 2250 kWh per ton of CO2, accompanied by electricity consumption rates varying from 366 to 2790 kWh per ton of CO2. The present study adopts the HT DAC method with an aqueous KOH absorbent as its focus, aiming to mitigate energy consumption. Given that a substantial portion of energy consumption in comparable processes can be attributed to the calciner and slaker units, our research centers its attention on the Air Separation Unit (ASU) and the steam cycle unit, investigating their impact on the system's production capacity, the enhancement of CO2 purity, and the augmentation of equipment thermal recovery. Process optimization, results a remarkable increase in heat recovery (21.1 %) and significant reductions in utilities consumption. The outcomes indicate that this facility has the capacity to annually capture around 1.1 million tons of CO2 with a purity of 99 mol% for utilization across various industries. The process design necessitates 5.24 gigajoules (GJ) of heat and 343 kW-hours (kWh) of electricity per ton of captured CO2. Notably, in addition to fulfilling the internal electricity requirements, the facility can export 8 MWh of electricity per ton of captured CO2 to the grid.

Abstract Background The association of the meal timing of dietary total antioxidant capacity (DAC) with mortality is unclear. We aimed to investigate the association between the meal timing of DAC and all-cause, cardiovascular disease (CVD), and cancer mortality in general adult populations. Methods A total of 56,066 adults who participated in the US National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 were recruited for this study. Dietary intake (quantity and timing) was evaluated by nonconsecutive 24-h dietary recalls. The main exposure variables were the DAC across three meals (total, breakfast, lunch, and dinner; without coffee) and the difference between dinner and breakfast DAC (Δ = dinner-breakfast; without coffee). The outcomes were all-cause, CVD, and cancer mortality. The adjusted hazard ratios [aHRs] and 95% confidence intervals [CI] were imputed by Cox proportional hazards regression. Results Among the 56,066 participants, there were 8566 deaths from any cause, including 2196 from CVD and 1984 from cancer causes. Compared to participants in the lowest quintiles of the total DAC, those in the highest quintiles had 34% and 27% decreased risks of all-cause and CVD mortality, respectively (all-cause mortality: aHRs 0.66 [95% CI 0.57–0.76]; CVD mortality: aHRs 0.73 [95% CI 0.57–0.94]). More importantly, participants in the highest quintiles of the dinner DAC, but not those in that of breakfast or lunch, had a 24% decrease in all-cause mortality (aHRs 0.76 [95% CI 0.67–0.87]) compared with those in the lowest quintiles. Inverse associations were further confirmed for Δ DAC (aHRs 0.84 [95% CI 0.74–0.96]). Above associations did not change when including DAC from snacks or tea. Mediation analysis showed that the total associations of total, dinner or Δ DACs with reduced all-cause mortality were 24%, 13% and 6%, respectively, mediated by serum CRP. Additionally, all-cause mortality was decreased by 7% in models replacing 10% breakfast DAC (aHRs 0.93 [95% CI 0.9–0.97]) with an equivalent proportion of dinner DAC. For cancer mortality, no statistical significance was detected in the adjusted models. Conclusions The findings emphasize the putative beneficial relationship of a diet rich in antioxidants and meal timing on serum CRP and all-cause mortality.

Ultrasonic signals can be conveniently recorded using modern high-speed analog-to-digital converters and analyzed through digital signal processing algorithms. Sometimes, in some applications, such as in bioacoustics, it is necessary to convert digital data to analog signals with a special transformation that allows compressing and translating the spectrum toward audible frequencies. The process is called time expansion and can be conveniently achieved by slowing down the frequency clock of a digital-to-analog converter. This paper analyzes in detail the spectral characteristics of a time-expanded signal.

Background Official Development Assistance (ODA) significantly aids sustainable development in low- and middle-income countries (LMICs). However, the COVID-19 pandemic has impacted aid allocation, posing challenges for attaining the Sustainable Development Goals (SDGs). Objective This study explores and underscores the profound implications of shifts in ODA allocation by Development Assistance Committee (DAC) member countries, resulting from the COVID-19 pandemic, offering a unique perspective on the evolving landscape of international aid. Methods Drawing from the gross ODA disbursement data for LMICs by DAC member countries from 2011 to 2021, a linear regression analysis assessed the changes in ODA amount, ODA-to-gross national income (GNI) ratio, sectoral aid allocation, and the balance between bilateral and multilateral aid, primarily focusing on the differences pre- and post-COVID-19. For non-specialised multilateral agencies’ core funding, the OECD’s methodology for calculating imputed multilateral ODA was employed to estimate ODA flows. Results The study found an increasing trend in the total ODA provided by DAC member countries from 2011 to 2021. However, the average ODA/GNI ratio showed a slight but significant decrease before the pandemic, followed by an increase after the COVID-19 pandemic. The health sector received the highest percentage of aid after the pandemic, with a marked increase in both bilateral and multilateral aid. However, other sectors such as humanitarian aid, water and sanitation, and energy experienced a significant decrease in sectoral aid share. Conclusions Emerging from this analysis is a strong recommendation for DAC members to re-evaluate aid objectives and escalate their financial commitments to reinforce SDGs and sustainable development efforts. While the rise in health aid is essential, other sectors also require equal focus to offset the ramifications of the COVID-19 pandemic. Understanding the intricacies of aid allocation can improve aid efficacy, culminating in greater, transformative results for recipient countries.

Hardware-in-the-loop (HIL) is a common technique used for testing in power electronics. It draws upon FPGAs (field-programmable gate arrays) because they allow for reaching real-time simulation for mid-high switching frequencies. FPGA area and delay are keys to reaching a compromise between performance and accuracy. To minimize area and delay, signal word length (WL) is critical. Furthermore, the input and output's WL should be carefully chosen because these signals come from ADCs (analog-to-digital converters) or go to DACs (digital-to-analog converters). In other words, the role of ADCs and DACs is the boundary condition when assigning all the signal WLs in an HIL model. This research presents an automatic method for computing the signal WLs in the corresponding model by considering input/output boundary conditions. This automatic method needs a single simulation to decide both the integer and fractional width of every signal. Our method accelerates the process, showing an advantage over manual methods and those requiring multiple simulations. The proposed method is applied to create all the WL assignments to the signals involved in a fixed-point coded buck converter model, which shows its feasibility. [ABSTRACT FROM AUTHOR]

Background: The association of the meal timing of dietary total antioxidant capacity (DAC) with mortality is unclear. We aimed to investigate the association between the meal timing of DAC and all-cause, cardiovascular disease (CVD), and cancer mortality in general adult populations. Methods: A total of 56,066 adults who participated in the US National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 were recruited for this study. Dietary intake (quantity and timing) was evaluated by nonconsecutive 24-h dietary recalls. The main exposure variables were the DAC across three meals (total, breakfast, lunch, and dinner; without coffee) and the difference between dinner and breakfast DAC (Δ = dinner-breakfast; without coffee). The outcomes were all-cause, CVD, and cancer mortality. The adjusted hazard ratios [aHRs] and 95% confidence intervals [CI] were imputed by Cox proportional hazards regression. Results: Among the 56,066 participants, there were 8566 deaths from any cause, including 2196 from CVD and 1984 from cancer causes. Compared to participants in the lowest quintiles of the total DAC, those in the highest quintiles had 34% and 27% decreased risks of all-cause and CVD mortality, respectively (all-cause mortality: aHRs 0.66 [95% CI 0.57–0.76]; CVD mortality: aHRs 0.73 [95% CI 0.57–0.94]). More importantly, participants in the highest quintiles of the dinner DAC, but not those in that of breakfast or lunch, had a 24% decrease in all-cause mortality (aHRs 0.76 [95% CI 0.67–0.87]) compared with those in the lowest quintiles. Inverse associations were further confirmed for Δ DAC (aHRs 0.84 [95% CI 0.74–0.96]). Above associations did not change when including DAC from snacks or tea. Mediation analysis showed that the total associations of total, dinner or Δ DACs with reduced all-cause mortality were 24%, 13% and 6%, respectively, mediated by serum CRP. Additionally, all-cause mortality was decreased by 7% in models replacing 10% breakfast DAC (aHRs 0.93 [95% CI 0.9–0.97]) with an equivalent proportion of dinner DAC. For cancer mortality, no statistical significance was detected in the adjusted models. Conclusions: The findings emphasize the putative beneficial relationship of a diet rich in antioxidants and meal timing on serum CRP and all-cause mortality. [ABSTRACT FROM AUTHOR]

This study is the first to propose the deployment of direct air capture (DAC) systems at large airports to provide solutions for achieving carbon neutrality in aviation transportation. Here, an estimating model for carbon dioxide (CO2) emissions in the landing and take-off (LTO) phase of large airports was developed, and the suitability of deploying DAC systems at airports was evaluated by the analytic hierarchy process (AHP). This study found that the annual CO2 emissions of 52 large airports in the LTO phase are about 23 Mt, accounting for about 23% of the total CO2 emissions of civil aviation in China. The four dimensions of airport transportation conditions, meteorological conditions, space resources, and security levels had a decreasing impact on the deployment of DAC systems in that order. The airports with suitable DAC systems are mainly located in the Yangtze River Delta, the Pearl River Delta, and the Chengdu-Chongqing Airport Cluster. This study provides a theoretical basis for the deployment of DAC systems at airports, which provides new CO2 emission reduction solutions for the aviation transportation industry. [ABSTRACT FROM AUTHOR]

Mutated cells may constitute a source of cancer. As an effective approach to quantifying the extent of cancer, cell image segmentation is of particular importance for understanding the mechanism of the disease, observing the degree of cancer cell lesions, and improving the efficiency of treatment and the useful effect of drugs. However, traditional image segmentation models are not ideal solutions for cancer cell image segmentation due to the fact that cancer cells are highly dense and vary in shape and size. To tackle this problem, this paper proposes a novel U-Net-based image segmentation model, named U-Net_dc, which expands twice the original U-Net encoder and decoder and, in addition, uses a skip connection operation between them, for better extraction of the image features. In addition, the feature maps of the last few U-Net layers are upsampled to the same size and then concatenated together for producing the final output, which allows the final feature map to retain many deep-level features. Moreover, dense atrous convolution (DAC) and residual multi-kernel pooling (RMP) modules are introduced between the encoder and decoder, which helps the model obtain receptive fields of different sizes, better extract rich feature expression, detect objects of different sizes, and better obtain context information. According to the results obtained from experiments conducted on the Tsinghua University's private dataset of endometrial cancer cells and the publicly available Data Science Bowl 2018 (DSB2018) dataset, the proposed U-Net_dc model outperforms all state-of-the-art models included in the performance comparison study, based on all evaluation metrics used. [ABSTRACT FROM AUTHOR]

Sectors such as aviation may require low-carbon liquid fuels to dramatically reduce emissions. This analysis characterizes the economic viability of electrofuels, synthesized from CO2 from direct air capture (DAC) and hydrogen from electrolysis of water, powered primarily by solar or wind electricity. This optimization-based techno-economic analysis suggests that using today's technology, hydrocarbon electrofuels would cost upward of $4/liter of gasoline equivalent (lge), potentially falling to $1.7-1.8/lge in the next decade and

Expanding populations and growing economies result in higher energy needs. Meeting this increasing demand, while lowering carbon emissions, calls for a broad energy mix and commercial deployment of solutions like carbon capture and carbon removal technologies. The scale-up of these solutions is partially hindered by the lack of materials-related information, particularly in the case of solid adsorption-based carbon capture technologies. Furthermore, experimental measurement parameters used and how data is presented lack uniformity, which makes material comparisons extremely difficult. This review examines the current state of solid sorbent characterization for carbon capture, exploring physical and chemical properties, performance parameters, and process indicators. Adsorbent performance parameters demonstrate to be the crucial link between intrinsic material properties and the overall adsorption process effectiveness and therefore are the focus of this work. This paper outlines the relevant techniques used to measure Key Performance Indicators (KPIs) related to adsorption performance such as CO2 adsorption capacity, selectivity, kinetics, ease of regeneration, stability, adsorbent cost, and environmental impact. Additionally, this study highlights the relevant experimental conditions for diluted versus concentrated CO2 streams. Lastly, efforts in harmonizing experimental data sets are considered, and an outlook on solid sorbent characterization for carbon capture processes is presented. Overall, the aim of this work is to provide the reader a critical understanding of KPIs from atomic to process scale, highlighting the importance of experimental data throughout.

The effect of the antioxidant capacity of diet and its distribution across three meals on mortality risk among cancer patients remains unexplored. We aimed to prospectively investigate the association of dietary total antioxidant capacity (DAC) and its distribution across three meals with all-cause, cancer, and noncancer mortality among cancer survivors. We included 5,009 patients with cancer from the National Health and Nutrition Examination Survey conducted between 1999 and 2018. The adjusted hazard ratio (aHR) was estimated using the survey-weighted Cox proportional hazards model. During a median follow-up of 7.9 years, 1811 deaths, including 575 cancer-related deaths, were recorded. Among cancer survivors, compared with participants in the lowest quartile of total DAC from three meals, those in the highest quartile had a 24% decreased risk of noncancer mortality (aHR = 0.76, 95% confidence interval [CI]: 0.60–0.92), but not of all-cause and cancer mortality (each p trend >0.1). However, this association became insignificant for total DAC after excluding dinner DAC. In addition, higher dinner DAC rather than breakfast or lunch DAC was associated with a 21% lower risk of all-cause mortality (aHR = 0.79, 95% CI: 0.65–0.98) and 28% lower risk of noncancer mortality (aHR = 0.72, 95% CI: 0.57–0.90). Similar associations were found for ΔDAC (dinner DAC − breakfast DAC) with noncancer mortality (aHR = 0.56, 95% CI: 0.38–0.83), but DAC was not associated with cancer mortality (p trend >0.3). Among cancer survivors, total DAC from three meals was associated with reduced noncancer mortality, with the primary effect attributable to increased DAC intake from dinner. Our findings emphasize that DAC consumption from dinner should be advocated to reduce mortality risk in cancer survivors.

Due to the composition-dependent stiffness of chemistry, simulations of reactive turbulent flows may present computational load imbalance among parallel processes when spatial decomposition is used for parallelisation, causing high CPU idle time and waste of computational resources. To increase computational efficiency, a dynamic load balancing (DLB) model is proposed to redistribute computational load among computing cores. The DLB model exploits a decomposition in the mixture fraction space with two dynamic adjusting decomposition strategies to realise load redistribution. The DLB model is suitable for the integration of chemistry on stochastic particles in hybrid Eulerian/Lagrangian turbulent combustion models in which the Eulerian field is conventionally decomposed statically in physical space in a way that balances the computational load for the solution of the Navier-Stokes equation but which does not generally lead to balanced load for the computation of the composition fields. Here it is tested using an OpenFOAM-based platform, mmcFoam, which is a comprehensive object-orientated C++ library for stochastic turbulent combustion modelling. Apart from direct integration (DI) for chemistry, the DLB model is also coupled with dynamic adaptive chemistry (DAC) and in situ adaptive tabulation (ISAT), which allows for extra speedup. The performance of the coupled models is validated and assessed for two laboratory flame conditions that exhibit different levels of computational load imbalance. Overall, the DLB model effectively balances the computational load distribution and increases the effective usage of computing power, shortening the simulation wall time required. Moreover, a strong scaling test is carried out using up to 512 cores. Although all approaches have sub-ideal scalability, the scalability of each with DLB is significantly better than without DLB. While DLB-ISAT has relatively poor scalability compared to the DI- and DAC-based methods, DLB-ISAT still ranks the fastest among the algorithms in all scaling trials. [ABSTRACT FROM AUTHOR]

Anaplastic thyroid cancer (ATC) is one of the most aggressive solid cancers in humans, with limited treatment options. Recent studies suggest that cancer stem cell (CSC) activity contributes to therapeutic resistance and recurrence of ATC. We show that the expression of the endogenous thyroid hormone receptor ß gene (THRB) is silenced in ATC and demonstrate that the exogenously expressed TRß suppresses CSC activity. Decitabine is one of the demethylation agents to treat myelodysplastic syndrome and acute myeloid leukemia patients and is currently in clinical trials for hematopoietic malignancies and solid tumors. We aim to show that the re-expression of the endogenous THRB gene by decitabine can attenuate CSC activity to block ATC tumor growth. We treated ATC cell lines derived from human ATC tumors (11T and 16T cells) with decitabine and evaluated the effects of the reactivated endogenous TRß on CSC activity in vitro and in vivo xenograft models. We found that treatment of 11T and 16T cells with decitabine reactivated the expression of endogenous TRß, as evidenced by western blot and immunohistochemical analyses. The expressed TRß inhibited cell proliferation by arresting cells at the S phase, increased apoptotic cell death by upregulation of cleaved caspase-3, and markedly suppressed the expression of CSC regulators, including cMYC, ALDH, SOX2, CD44, and ß-catenin. Decitabine also inhibited xenograft tumor growth by suppressing CSC activity, inhibiting cancer cell proliferation, and increasing apoptosis. Our findings suggest that re-expression of the endogenous TRß is a novel therapeutic approach for ATC via suppression of CSC activity. [ABSTRACT FROM AUTHOR]

Organizations and other institutions have recently started using cloud service providers to store and share information in light of the Internet of Things (IoT). The major issues with this storage are preventing unauthorized access and data theft from outside parties. The Block chain based Security Sharing scheme with Data Access Control (BSSDAC) was implemented to improve access control and secure data transaction operations. The goal of this research is to strengthen Data Access Control (DAC) and security in IoT applications. To improve the security of personal data, cypher text-Policy Attribute-Based Encryption (CP-ABE) can be developed. The Aquila Optimization Algorithm (AOA) generates keys in the CP-ABE. DAC based on a block chain can be created to maintain the owner's security. The block chain based CP-ABE was developed to maintain secures data storage to sharing. With block chain technology, the data owner is enhancing data security and access management. Finally, a block chain-based solution can be used to secure data and restrict who has access to it. Performance of the suggested method is evaluated after it has been implemented in MATLAB. To compare the proposed method with current practices, Rivest-Shamir-Adleman (RSA) and Elliptic Curve Cryptography (ECC) are both used. [ABSTRACT FROM AUTHOR]

Quantum key distribution (QKD) theoretically achieves unconditional security for communication. However, the secret-key rate is limited, which can be enhanced by increasing the repetition rate of QKD. Additionally, to achieve a small form factor instead of a large one in a printed-circuit-board (PCB) solution, a novel integrated modulator driving circuit is proposed in this paper, which can realize adjustable amplitude and pulse width with a maximum repetition rate of 4 GHz. In the proposed architecture, four low-speed digital-to-analog converters (DACs) instead of one high-speed DAC are utilized to tune the pulse amplitude, so low cost and high-level output are achieved. The modulator driving circuit can output a random return-to-zero (RZ) pulse train with four different pulse amplitudes. Operated with 1.8 V supply, the four levels with a minimum 1.76 mV tunable accuracy cover a range of 0–225 mV, 225–450 mV, 450–900 mV, and 0.9–1.8 V, respectively. A 4-bit and a 6-bit controller are applied to the modulator driving circuit to achieve different pulse widths. Fabricated in 130-nm CMOS technology, the proposed modulator driving circuit occupies a core area of 7.6 mm2 and consumes 612 mW. A repetition rate of 4 GHz is achieved and the measured pulse amplitude ranges from 77 mV to 1.67 V and the range of pulse width is 140 ps to 1049 ps. [ABSTRACT FROM AUTHOR]

This paper presents a design of 4 bit differential current steering(DCS) DAC as a part of 16bit PAM transmitter (4-b/symbol) for achieving 4Gb/s data rate in 45-nm CMOS technology. The 4-bit folding flash ADC circuit is used in the receiver to complete the transceiver chain for the wireless communication. 4-b ADC and the binary to thermometer converter block will convert the single-ended continuous time input to 15-b thermometer code at 1 GHz clock. The 4-bit thermometer DCS DAC which takes the 15-b digital input and provides output current to drive the channel. The channel is terminated at the receiver with a terminating resistor (RT) and a terminating voltage (VT). All the IC design challenges are suitable with the CMOS technology for the communication devices and internet of things. Hence DAC is designed in 45-nm technology for the proposed work and overall achieved parameter results are compared with different topologies. For the 1 V applied voltage the whole system has the power consumption as 11.244mW and the ENOB of 3.953@29Mhz. [ABSTRACT FROM AUTHOR]

The recent developments in biosignal acquisition devices for continuous supervision of cardiovascular signs of high-risk patients require a high-precision and low-power Analog Front End (AFE) circuit. The proposed design adopts Continuous-Time (CT) Sigma-Delta Modulator (ΣΔM) architecture to achieve high resolution and SIgnal-to-Noise And Distortion ratio (SINAD) requirements. The proposed modulator is a second-order CT-ΣΔM with Cascade of Integrators Feed-Forward (CIFF) architecture that consists of a CT loop filter, a single-bit quantizer, and a Digital-to-Analog Converter (DAC). The use of single-bit quantization in the design reduces circuit complexity and power consumption. To use the designed ΣΔM for measuring ECG signals, a bandwidth (Bw) of 150 Hz is considered with a sampling frequency (fs) of 153.6kHz to achieve an oversampling ratio of 512. The design is simulated in a standard Cadence Virtuoso EDA tool at 180nm CMOS technology, operating at 1.8V supply voltage at the block level. The simulation results for the designed modulator show that SINAD is 104.5dB, the Effective Number Of Bits (ENOB) is 17.06bits, with power consumption of 24μW, and achieves Schreier's Figure-Of-Merit (FOM) equal to 172.45dB. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Official Development Assistance (ODA) significantly aids sustainable development in low- and middle-income countries (LMICs). However, the COVID-19 pandemic has impacted aid allocation, posing challenges for attaining the Sustainable Development Goals (SDGs). This study explores and underscores the profound implications of shifts in ODA allocation by Development Assistance Committee (DAC) member countries, resulting from the COVID-19 pandemic, offering a unique perspective on the evolving landscape of international aid. Drawing from the gross ODA disbursement data for LMICs by DAC member countries from 2011 to 2021, a linear regression analysis assessed the changes in ODA amount, ODA-to-gross national income (GNI) ratio, sectoral aid allocation, and the balance between bilateral and multilateral aid, primarily focusing on the differences pre- and post-COVID-19. For non-specialised multilateral agencies' core funding, the OECD's methodology for calculating imputed multilateral ODA was employed to estimate ODA flows. The study found an increasing trend in the total ODA provided by DAC member countries from 2011 to 2021. However, the average ODA/GNI ratio showed a slight but significant decrease before the pandemic, followed by an increase after the COVID-19 pandemic. The health sector received the highest percentage of aid after the pandemic, with a marked increase in both bilateral and multilateral aid. However, other sectors such as humanitarian aid, water and sanitation, and energy experienced a significant decrease in sectoral aid share. Emerging from this analysis is a strong recommendation for DAC members to re-evaluate aid objectives and escalate their financial commitments to reinforce SDGs and sustainable development efforts. While the rise in health aid is essential, other sectors also require equal focus to offset the ramifications of the COVID-19 pandemic. Understanding the intricacies of aid allocation can improve aid efficacy, culminating in greater, transformative results for recipient countries. [ABSTRACT FROM AUTHOR]

This article reports a two-stage differential structure power amplifier based on a 130 nm SiGe process operating at 77 GHz. By introducing a tunable capacitor for amplitude and phase balance at the center tap of the secondary coil of the traditional Marchand balun, the balun achieves amplitude imbalance less than 0.5 dB and phase imbalance less than 1 degree within the operating frequency range of 70–85 GHz, which enables the power amplifier to exhibit comparable output power over a wide operating frequency band. The power amplifier, based on a designed 3-bit digital analog convertor (DAC)-controlled base bias current source, exhibits small signal gain fluctuation of less than 5 dB and saturation output power fluctuation of less than 2 dB near the 80 GHz frequency point when the ambient temperature varies in the range of −40 °C to 125 °C. Benefiting from the aforementioned design, the tested single-path differential power amplifier exhibits a small signal gain exceeding 16 dB, a saturation output power exceeding 18 dBm, and a peak saturation output power of 19.1 dBm in the frequency band of 70–85 GHz.

Currently, cloud storage servers are controlled by a third-party administrator. This semi-trusted approach gives rise to security concerns. Therefore, in cloud computing, some protocols use a key manager to encrypt the user’s private data before uploading the data to the cloud. However, the security concerns that arise from the use of a key manager are not yet solved. In this respect, in this paper, a provably secure user cloud data access control protocol (DAC) is proposed based on existing cloud storage. Empirical tests confirm that the proposed approach is highly secure against adaptive selective ciphertext attacks and has excellent resistance to message attacks. A comprehensive performance evaluation, including time measurements, is conducted and the protocol is compared to other protocols, revealing the efficient file upload and download processes of the proposed approach. The results demonstrate the protocol’s strong security, practicality, and operational efficiency.

The recent developments in biosignal acquisition devices for continuous supervision of cardiovascular signs of high-risk patients require a high-precision and low-power Analog Front End (AFE) circuit. The proposed design adopts Continuous-Time (CT) Sigma-Delta Modulator (ΣΔM) architecture to achieve high resolution and SIgnal-to-Noise And Distortion ratio (SINAD) requirements. The proposed modulator is a second-order CT-ΣΔM with Cascade of Integrators Feed-Forward (CIFF) architecture that consists of a CT loop filter, a single-bit quantizer, and a Digital-to-Analog Converter (DAC). The use of single-bit quantization in the design reduces circuit complexity and power consumption. To use the designed ΣΔM for measuring ECG signals, a bandwidth (Bw) of 150 Hz is considered with a sampling frequency (fs) of 153.6kHz to achieve an oversampling ratio of 512. The design is simulated in a standard Cadence Virtuoso EDA tool at 180nm CMOS technology, operating at 1.8V supply voltage at the block level. The simulation results for the designed modulator show that SINAD is 104.5dB, the Effective Number Of Bits (ENOB) is 17.06bits, with power consumption of 24µW, and achieves Schreier’s Figure-Of-Merit (FOM) equal to 172.45dB.

The isolation of cyclic(alkyl)(amino)carbenes (CAACs) and N,N′‐diamidocarbenes (DACs) has opened up new avenues in the field of carbene chemistry due to their unique properties. CAACs are strong σ‐donors and π‐acceptors, whereas DACs are extremely strong π‐acceptors. The ambiphilicity of carbenes can facilitate new applications such as small molecule activation and catalysis. Since the isolation of CAACs and DACs, several new ambiphilic carbenes have been synthesized, thereby advancing the development of carbene chemistry. This review summarizes the most relevant findings on ambiphilic carbene chemistry until 2022. [ABSTRACT FROM AUTHOR]