Hydrogen production from the air Guo, Jining; Zhang, Yuecheng; Zavabeti, Ali ...
Nature communications,
09/2022, Volume:
13, Issue:
1
Journal Article
Peer reviewed
Open access
Abstract
Green hydrogen produced by water splitting using renewable energy is the most promising energy carrier of the low-carbon economy. However, the geographic mismatch between renewables ...distribution and freshwater availability poses a significant challenge to its production. Here, we demonstrate a method of direct hydrogen production from the air, namely, in situ capture of freshwater from the atmosphere using hygroscopic electrolyte and electrolysis powered by solar or wind with a current density up to 574 mA cm
−2
. A prototype of such has been established and operated for 12 consecutive days with a stable performance at a Faradaic efficiency around 95%. This so-called direct air electrolysis (DAE) module can work under a bone-dry environment with a relative humidity of 4%, overcoming water supply issues and producing green hydrogen sustainably with minimal impact to the environment. The DAE modules can be easily scaled to provide hydrogen to remote, (semi-) arid, and scattered areas.
•Monosaccharides, organic acids and phenolic compounds in HTL hydrolysates were recovered.•Hydrolysates derived from different conditions were separated by different ion exchange resins.•Separation ...processes of typical compounds: glucose, acetic acid and phenol, were inspected.
This paper describes two effective ion exchange chromatography processes to separate and recover monosaccharides, organic acids and phenolic compounds from two kinds of hydrothermal liquefaction (HTL) hydrolysates derived under different temperatures. Anion exchange resin Amberlyst A21 (OH−) and cation exchange resin Amberlite IR-120 (Na+) were selected to separate synthetic solution and real hydrolystes by column chromatography. The results showed that glucose and acetic acid could be successfully separated by anion resin with purities of 87% and 98%, respectively. Acetic acid and phenol could be recovered by cation resin with purities up to 97% and 81%. In separation processes of real HTL hydrolysates, monosaccharides and organic acids in hydrolysate derived from low-temperature HTL were separated by anion exchange resin with recoveries of about 80% and 90%, respectively. Phenolic compounds in high-temperature HTL hydrolysate were recovered by cation exchange resin with recovery of about 70%.
ABSTRACT
Background and Objective
Epidemiological studies suggested that the association between the visceral adiposity index (VAI) and the risk of prediabetes is inconsistent. Whether VAI is a ...useful predictor of prediabetes remains unclear. Up until April 2021, there had been no systematic review on this topic. In this meta‐analysis, the available observational epidemiological evidence was synthesized to identify the association between VAI and prediabetes risk.
Methods
PubMed, EMBASE, and Cochrane databases in any language were searched systematically from the earliest available online indexing year to April 2021 for relevant observational studies published on the association between VAI and the risk of prediabetes. A random effects model was used to combine quantitatively the odds ratios (ORs) and 95% confidence intervals (CIs).
Results
Ten relevant studies (2 cohort study, 2 case‐control studies, and 6 cross‐sectional studies) involving 112,603 participants were identified. Compared with the highest VAI, the lowest level of VAI was associated with an increased risk of prediabetes. The pooled OR of VAI for prediabetes was 1.68 (95% CI: 1.44–1.96), with significant heterogeneity across the included studies (P = 0.000, I2 = 91.4%). Exclusion of any single study did not materially alter the combined risk estimate.
Conclusions
Integrated epidemiological evidence supports the hypothesis that VAI is a lipid combined anthropometric index and may be a risk factor for prediabetes. VAI may be related to a high risk of prediabetes. However, it should be noted that the included studies have a publication bias and there was significant heterogeneity between our pooled estimate.
The present manuscript focuses on whether VAI is a useful predictor of prediabetes. Integrated epidemiological evidence supports the hypothesis that VAI is a lipid combined anthropometric index and may be a risk factor for prediabetes. VAI is significantly related to a high risk of prediabetes.
Abstract
While multiple external stimuli (e.g., temperature, light, pressure) have been reported to regulate gas adsorption, limited studies have been conducted on controlling molecular admission in ...nanopores through the application of electric fields (E-field). Here we show gas adsorption capacity and selectivity in zeolite molecular sieves can be regulated by an external E-field. Through E-field pre-activation during degassing, several zeolites exhibited enhanced CO
2
adsorption and decreased CH
4
and N
2
adsorptions, improving the CO
2
/CH
4
and CO
2
/N
2
separation selectivity by at least 25%. The enhanced separation performance of the zeolites pre-activated by E-field was maintained in multiple adsorption/desorption cycles. Powder X-ray diffraction analysis and ab initio computational studies revealed that the cation relocation and framework expansion induced by the E-field accounted for the changes in gas adsorption capacities. These findings demonstrate a regulation approach to sharpen the molecular sieving capability by E-fields and open new avenues for carbon capture and molecular separations.
Bio-oil obtained from hydrothermal liquefaction of Salix psammophila is a very complicated mixture with some highly valued chemicals. In order to separate the chemicals from bio-oil, solvent ...extraction using nine solvents with different polarities were investigated in detail. The bio-oil extraction yield of the nine solvents were from high to low: tetrahydrofuran > toluene > ethyl acetate > acetone > ether > methylene chloride > methanol > petroleum ether > n-hexane. Based on their extraction yield, an efficient solvent combination of n-hexane, ethyl acetate, and tetrahydrofuran was used to separate the bio-oil through multistep extraction into three parts: light oil (26.13%), mid-weight oil (54.19%), and heavy oil (19.68%). These fractions were characterized by gas chromatography-mass spectrometry, Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and thermogravimetric analysis. The results showed that most of the highly valued chemicals were contained in the light oil; the mid-weight oil consisted of aromatic oligomer derived from the decomposition of lignin, which could be a promising candidate for partial substitute for petroleum-asphalt binder; the heavy oil was rich in alkanes.
Capacitorless DRAM architectures based on Back-End-of-Line (BEOL)-transistors are promising for long-retention, high-density and low-power 3D DRAM solutions due to its low leakage, operational ...flexibility, and monolithic integration capability. Different from classical silicon-based devices, in-depth studies on the performances of nanoscale multi-gate transistors (e.g., a-InGaZnO-FET) are still barely conducted for physical description, due to the complicated multi-gating principle, finite-size effects on transport, increased variation sources and enlarged parasitic effect. Hence, high-performance multi-nanoscale (down to <inline-formula> <tex-math notation="LaTeX">\sim ~50 </tex-math></inline-formula> nm) dual-gate a-IGZO transistors are fabricated, and a physical compact model is developed based on the surface potential for dual-gated coupling and the disordered transport with finite-size-correction. The short channel behaviors on sub-threshold swing, mobility and threshold voltage are investigated, and contact effects are validated by the transfer-line method (TLM). Regarding the specific challenge of dual-gate alignment, possible misalignment and parasitic effects on multi-device fluctuations are important of large-scale circuit design and analyzed by TCAD simulations. Besides, the bias-temperature instability (BTI) has been comprehensively investigated. In awareness of the above effects, this model bridges fabrication-based material properties and structural parameters, assisting in a threshold fluctuation-resistant operation scheme for capacitorless multi-bit memory, showing a great potential in future monolithic integration circuit design using BEOL-transistor.
Accurate assessment of the clinical staging is crucial for determining the need for radical prostatectomy (RP) in prostate cancer (PCa). However, the current methods for PCa staging may yield ...incorrect results. This study aimed to comprehensively analyze independent predictors of postoperative upstaging of intraprostatic cancer.
We conducted a retrospective analysis of data from intraprostatic cancer patients who underwent radical surgery between March 2019 and December 2022. Intraprostatic cancer was defined as a lesion confined to the prostate, excluding cases where multiparameter magnetic resonance imaging (mpMRI) showed the lesion in contact with the prostatic capsule. We assessed independent predictors of extraprostatic extension (EPE) and analyzed their association with positive surgical margin (PSM) status. In addition, based on the distance of the lesion from the capsule on mpMRI, we divided the patients into non-transition zone and transition zone groups for further analysis.
A total of 500 patients were included in our study. Logistic regression analysis revealed that biopsy Gleason grade group (GG) (odds ratio, OR: 1.370, 95% confidence interval, CI: 1.093-1.718) and perineural invasion (PNI) (OR: 2.746, 95% CI: 1.420-5.309) were predictive factors for postoperative EPE. Both biopsy GG and PNI were associated with lateral (GG: OR: 1.270, 95% CI: 1.074-1.501; PNI: OR: 2.733, 95% CI: 1.521-4.911) and basal (GG: OR: 1.491, 95% CI: 1.194-1.862; PNI: OR: 3.730, 95% CI: 1.929-7.214) PSM but not with apex PSM (GG: OR: 1.176, 95% CI: 0.989-1.399; PNI: OR: 1.204, 95% CI: 0.609-2.381) after RP. Finally, PNI was an independent predictor of EPE in the transition zone (OR: 11.235, 95% CI: 2.779-45.428) but not in the non-transition zone (OR: 1.942, 95% CI: 0.920-4.098).
PNI and higher GG may indicate upstaging of tumors in patients with intraprostatic carcinoma. These two factors are associated with PSM in locations other than the apex of the prostate. Importantly, cancer in the transition zone of the prostate is more likely to spread externally through nerve invasion than cancer in the non-transition zone.
Nanosheet (NS) vertical‐stacked complementary field‐effect transistors (CFETs), where the NS n‐FET and NS p‐FET are vertically stacked and controlled using a common gate, would result in maximum ...device footprint reduction. However, silicon‐based transistor will become invalid due to mobility degradation and leakage current rising when scaling the thickness of channel and dielectric. Here, it is experimentally demonstrated that CFET can scaling down to 1 nm channel thickness with excellent performance, where chemical vapor deposition (CVD) one layer (1L) WSe2 p‐type NS FET is vertically stacked on top of CVD 1L MoS2 n‐type NS FET. Bottom MoS2 NS FET achieves high on‐state current of ION = 3.3 × 10−5 A µm µm−1 and low off‐state current of IOFF = 3.3 × 10−13 A µm µm−1 at VDS = 0.7 V, with the subthreshold swing reaching 80 mV dec−1. Top WSe2 NS FET achieves high on‐state current of ION = 1.2 × 10−5 A µm µm−1 and IOFF = 4 × 10−11 A µm µm−1 at VDS = −0.7 V, while the subthreshold swing reaching 150 mV dec−1. Statistical data of 22 CFET devices demonstrate excellent uniformity toward large‐area applications. The CFET based on large‐scale 2D materials breaks the limit of channel scaling and provides a technological base for future high‐performance and low‐power electronics.
A nanosheet‐stacked complementary FET based on CVD monolayer MoS2/WSe2 is presented. The FET shows high drive current and low leakage current attributed to the GAA structure and 2D semiconductors electrical properties. Statistical data demonstrate excellent uniformity toward large‐area applications. The results break the limit of channel‐scaling, and pave the way for high‐performance and low‐power electronics.
Although layered MoS2 has been proposed as a potential candidate for gas detection devices due to high surface-to-volume ratio, high sensitivity, and selectivity, the adsorption behavior of small ...molecules is still ambiguous. Here, we performed the first-principles calculations to investigate the adsorption behavior of small molecules on layered MoS2 surface, and the effects of defects and environment are considered. Our results reveal that NO and NO2 can be chemically adsorbed on defective monolayer MoS2, which is attributed to the forming of covalent bonds. And the forming of covalent bonds can lead to an increase in adsorption energies. Whereas, gas molecules can only be physically adsorbed on perfect MoS2. Meanwhile, as compared with adsorption behavior of NH3, NO, and NO2 on clean MoS2, the environmental gases (CO2, N2, and H2O) may result in an increase in adsorption strength of NH3, NO, and NO2 on MoS2 surface.
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