We successfully used Cu to dope into the NiWO4 crystal to prevent the fast recombination or increase the lifetime of the photo-induced h+ and e− of the material. Then, the synthesized Cu-NiWO4 was ...successfully hybridized with g-C3N4 to form Cu-NiWO4/g-C3N4 direct Z system for novel photocatalytic decomposition of n-hexane under vis-light. In the formed Cu-NiWO4/g-C3N4 Z direct system, photo-induced e− in Cu-NiWO4 CB associated with photo-induced h+ in g-C3N4 VB maintaining e− in g-C3N4 CB and h+ in Cu-NiWO4 VB, thereby synthesized photocatalysts formed abundant available e− and h+ amounts even excited by vis-light and the formed e− and h+ pairs exhibit suitable redox potentials for reactions with O2 and H2O, respectively, to produce strong oxidative radicals for advanced photocatalytic degradation of n-hexane. The highest removal efficiency and degradation degree of n-hexane photocatalyzed by Cu-NiWO4/g-C3N4 were 96.8 and 96.3%, respectively. The synthesized Cu-NiWO4/g-C3N4 material also demonstrated strongly stability during long time n-hexane removal.
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•Successfully doped Cu into NiWO4 lattice to enhance its photocatalytic activity.•Cu dopant prevented recombination of photo-excited e− and h+ of the NiWO4.•Cu-NiWO4 was successfully combined with g-C3N4 to establish Z direct scheme system.•Z-scheme prevented fast recombination of e− and h+ and remained their oxidative ability.•The Cu-NiWO4/g-C3N4 exhibited excellent photocatalytic degradation of gaseous n-hexane.
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•Cu doped TiO2 was synthesized to enhanced the photocatalytic water splitting.•Cu doped TiO2 exhibited excellent visible-light photocatalytic H2 generation (45.6 mmol/h)•Cu-TiO2 can ...reused five times without the loss of H2 production capacity.•Cu-TiO2-based photocatalyst has potential to apply for sustainable H2 production.
Titanium dioxide (TiO2) based materials were used in many fields such as energy application, biological and environment remediation control. In this study, copper-doped TiO2 (Cu-TiO2) was synthesized and investigated for photocatalytic water splitting hydrogen (H2) evolution. The doping of Cu ions not only increased the oxygen vacancies but also improved the charge separation of photocatalyst. The Cu-TiO2 displayed a higher the rate of H2 evolution (45.6 mmol/h) as compared to undoped TiO2 (0.73 mmol/h). The reused of material was identified and the photocatalytic water splitting mechanism of Cu-TiO2 was proposed. The results showed that, Cu-TiO2 had high stability after reusing for 5 consecutive cycles without the loss of H2 production capacity. In addition, practical application and future research were discussed in details. This work may contribute to the potential application of TiO2-based photocatalyst for water splitting in order to produce H2 gas as green energy.
A 27 wt.% Cr white cast iron has been subjected to various destabilization heat treatments. The transformation of the matrix phase as well as the precipitatiopn of secondary carbides by ...destabilization heat treatments, which have been clearly determined in this paper. The results revealed that in the destabilization temperature (about 880°C), the matrix phase is enriched with elements such as C and Cr, due to dissolution of eutectic carbides at high temperature. The secondary carbides were precipitated along grain boundary of C, Cr- rich matrix, they grew up within the matrix phase. When the destabilization temperature increases up to 1000°C the number, volume and size of secondary carbides also increase, respectively (secondary carbide size up to 2,22 µm). At 1050°C/3 h, the size of secondary carbides reduce significantly with a high distribution density in the matrix phase (grain size reduce to below 0,8 µm). At 1100°C and holding time for 3 hours, secondary carbides were dissolved into the matrix, and therefore, reduce the number and grain size of secondary carbides. Effects of secondary carbides on corrosion of alloy were determined by polarization test of alloys in H2SO4 5 vol.% solution at room temperature, by the depth of corrosion layer and by microstructure analyzing of corroded surfaces of alloys. The 1050°C/3 h alloy is the best corrosion resistance between the tested alloys with a large amount of fine secondary carbides and uniformly distributed within the matrix.
The SPOT-MAS assay "Screening for the Presence Of Tumor by Methylation And Size" detects the five most common cancers in Vietnam by evaluating circulating tumor DNA in the blood. Here, we validated ...its performance in a prospective multi-center clinical trial, K-DETEK. Our analysis of 2795 participants from 14 sites across Vietnam demonstrates its ability to detect cancers in asymptomatic individuals with a positive predictive value of 60%, with 83.3% accuracy in detecting tumor location. We present a case report to support further using SPOT-MAS as a complementary method to achieve early cancer detection and provide the opportunity for early treatment.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•The min-cost parallel drone scheduling vehicle routing problem (PDSVRP) is introduced.•A mixed integer linear program and a Ruin and Recreate (R&R) algorithm are proposed.•Extensive experiments are ...carried out to investigate the performance of the methods.•CART method is used to perform a sensitivity analysis on the impact of drone delivery.•R&R dominates other algorithms proposed for the PDSTSP in terms of solution quality.
Adopting unmanned aerial vehicles (UAV), also known as drones, into the last-mile-delivery sector and having them work alongside trucks with the aim of improving service quality and reducing the transportation cost gives rise to a new class of Vehicle Routing Problems (VRPs). In this paper, we introduce a new optimization problem called the min-cost Parallel Drone Scheduling Vehicle Routing Problem (PDSVRP). This problem is a variant of the well-known Parallel Drone Scheduling Traveling Salesman Problem (PDSTSP) recently introduced in the literature in which we allow multiple trucks and consider the objective of minimizing the total transportation costs. We formulate the problem as a Mixed Integer Linear Program and then develop a Ruin and Recreate (R&R) algorithm. Exploiting PDSVRP solution characteristics in an effective manner, our heuristic manages to introduce “sufficient” rooms to a solution via new removal operators during the ruin phase. It is expected to enhance the possibilities for improving solutions later in the recreate phase. Multiple experiments on a new set of randomly generated instances confirm the performance of our approach. To explore the benefits of drone delivery as well as the insight into the impact of related factors on the contribution of drones’ use to operational cost, a sensitivity analysis is conducted. We also adapt the proposed algorithm to solve the PDSTSP and validate it via benchmarks available in the literature. It is shown that our algorithm outperforms state-of-the-art algorithms in terms of solution quality. Out of 90 considered instances, it finds 26 new best known solutions.
This study investigated the biomass production process from the laboratory to the pilot scale in order to use the nutrient-rich biomass of the diatom
Thalassiosira weissflogii
as live feed for ...white-leg shrimp (
Litopenaeus vannamei
) at larval stages (zoeal, mysis, and postlarval) and in commercial production in hatcheries in Vietnam. Our results showed that
T
.
weissflogii
was successfully cultured in 1–2 L Erlenmeyer flasks, 0.2–3.5 m
3
composite tanks, and 6.5 m
3
tubular photobioreactors, with the highest cell density of 1.6 × 10
6
cells mL
−1
reached after 6 days of culture. Under optimal culture conditions, the protein, lipid, and carbohydrate contents in this algal biomass were 13.2%, 20.0%, and 10.0% of dry cell weight, respectively. The fatty acid composition contains high amount of palmitic acid (C16:0, 43.11% of total fatty acid), and polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, C20:5ω-3), approximated 16.5% of total fatty acid. In a 50 L larval rearing tank, at the optimal stocking density of 125 nauplii L
−1
, the survival percentage (75.55%), the total body length (from 5.376 ± 0.007 to 10.860 ± 0.030 mm), and weight (at from PL
1
to PL
12
stages) (from 0.145 ± 0.002 to 1.158 ± 0.005 g) of the white-leg shrimp larvae reached the highest values but the metamorphosis time (234 h) was shortest compared with the other stocking densities. Further, adding living
T
.
weissflogii
biomass to the diet of white-leg shrimp larvae at the nauplii 6 stage led to an increase in the body length, weight, and survival percentage of white-leg shrimp larvae of 21.17%, 35.7%, and 33% higher compared with those of larvae fed the control diet (without the addition of
T
.
weissflogii
), respectively. At the same time, the metamorphosis time of larvae (from Z
1
to PL
1
) decreased by 4 h compared to the control group. In intensive ponds (area of 6400 m
2
pond
−1
), using seed stocks at the postlarvae 12 stage that had been fed
T
.
weissflogii
, the final weight, yield, and survival percentage of the shrimp were increased by 7.3%, 14.2%, and 16.3%, respectively, compared with those of the control group. There were no statistically significant differences in the protein and carbohydrate contents in the shrimp flesh among the experimental and control group (
p
> 0.05). The lipid, omega-3, omega-6, and omega-9 fatty acid contents of shrimp flesh in experiment formula (per 100 g shrimp) were 1.21 g, 72.9 mg, 114 mg, and 86.1 mg, 11%, 29%, 21.6%, and 17.7% higher than that those in control, respectively. The obtained results show the great potential of using
T
.
weissflogii
as live feed on white-leg shrimp farms in Vietnam.
Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little ...is known of the risk factors underlying the disease.
A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating "high risk" dishes, including such dishes as undercooked pig blood and pig intestine (OR(1) = 2.22; 95%CI = 1.15-4.28 and OR(2) = 4.44; 95%CI = 2.15-9.15), occupations related to pigs (OR(1) = 3.84; 95%CI = 1.32-11.11 and OR(2) = 5.52; 95%CI = 1.49-20.39), and exposures to pigs or pork in the presence of skin injuries (OR(1) = 7.48; 95%CI = 1.97-28.44 and OR(2) = 15.96; 95%CI = 2.97-85.72). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection.
This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating 'high risk' dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In a lot of engineering applications, one has to recover the temperature of a heat body having a surface that cannot be measured directly. This raises an inverse problem of determining the ...temperature on the surface of a body using interior measurements, which is called the sideways problem. Many papers investigated the problem (with or without fractional derivatives) by using the Cauchy data
u(x0,t),ux(x0,t)$$ u\left({x}_0,t\right),{u}_x\left({x}_0,t\right) $$ measured at one interior point
x=x0∈(0,L)$$ x={x}_0\in \left(0,L\right) $$ or using an interior data
u(x0,t)$$ u\left({x}_0,t\right) $$ and the assumption
limx→∞u(x,t)=0$$ {\lim}_{x\to \infty }u\left(x,t\right)=0 $$. However, the flux
ux(x0,t)$$ {u}_x\left({x}_0,t\right) $$ is not easy to measure, and the temperature assumption at infinity is inappropriate for a bounded body. Hence, in the present paper, we consider a fractional sideways problem, in which the interior measurements at two interior point, namely,
x=1$$ x=1 $$ and
x=2$$ x=2 $$, are given by continuous data with deterministic noises and by discrete data contaminated with random noises. We show that the problem is severely ill‐posed and further constructs an a posteriori optimal truncation regularization method for the deterministic data, and we also construct a nonparametric regularization for the discrete random data. Numerical examples show that the proposed method works well.
Along with the development of the Internet of Things (IoT), waste management has appeared as a serious issue. Waste management is a daily task in urban areas, which requires a large amount of labour ...resources and affects natural, budgetary, efficiency, and social aspects. Many approaches have been proposed to optimize waste management, such as using the nearest neighbour search, colony optimization, genetic algorithm, and particle swarm optimization methods. However, the results are still too vague and cannot be applied in real systems, such as in universities or cities. Recently, there has been a trend of combining optimal waste management strategies with low-cost IoT architectures. In this paper, we propose a novel method that vigorously and efficiently achieves waste management by predicting the probability of the waste level in trash bins. By using machine learning and graph theory, the system can optimize the collection of waste with the shortest path. This article presents an investigation case implemented at the real campus of Ton Duc Thang University (Vietnam) to evaluate the performance and practicability of the system’s implementation. We examine data transfer on the LoRa module and demonstrate the advantages of the proposed system, which is implemented through a simple circuit designed with low cost, ease of use, and replace ability. Our system saves time by finding the best route in the management of waste collection.
Despite their promise, circulating tumor DNA (ctDNA)-based assays for multi-cancer early detection face challenges in test performance, due mostly to the limited abundance of ctDNA and its inherent ...variability. To address these challenges, published assays to date demanded a very high-depth sequencing, resulting in an elevated price of test. Herein, we developed a multimodal assay called SPOT-MAS (screening for the presence of tumor by methylation and size) to simultaneously profile methylomics, fragmentomics, copy number, and end motifs in a single workflow using targeted and shallow genome-wide sequencing (~0.55×) of cell-free DNA. We applied SPOT-MAS to 738 non-metastatic patients with breast, colorectal, gastric, lung, and liver cancer, and 1550 healthy controls. We then employed machine learning to extract multiple cancer and tissue-specific signatures for detecting and locating cancer. SPOT-MAS successfully detected the five cancer types with a sensitivity of 72.4% at 97.0% specificity. The sensitivities for detecting early-stage cancers were 73.9% and 62.3% for stages I and II, respectively, increasing to 88.3% for non-metastatic stage IIIA. For tumor-of-origin, our assay achieved an accuracy of 0.7. Our study demonstrates comparable performance to other ctDNA-based assays while requiring significantly lower sequencing depth, making it economically feasible for population-wide screening.
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