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1.
Environ Sci Pollut Res Int ; 31(10): 15209-15222, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38289558

ABSTRACT

Utilizing cost-effective corn cob, zinc chloride-modified biochar was synthesized through one-step method for benzene adsorption from air. Study on impregnation ratio impact showed optimal benzene adsorption at ZnCl2:CC ratio of 1.5:1, with capacity reaching 170.53 mg g-1. Characterization using BET, SEM, FTIR, and XPS was conducted. BET results indicated specific surface area of Zn1.5BC at 1260.63 m2 g-1 and maximum pore volume of 0.546 m3 g-1. SEM analysis revealed microporous-mesoporous structure in Zn1.5BC, marking significant improvement over original biomass. DFT pore size distribution and FTIR analysis suggested post-modification dehydration and elimination reactions, leading to volatile compound release, functional group reduction, and pore widening. XPS analysis showed decrease in O = C-OH content with increased impregnation ratio, enhancing biochar's π-π electron diffusion for benzene. Langmuir isotherm and pseudo-second-order kinetic models effectively described experimental data, indicating multilayer benzene adsorption on biochar controlled by complex physicochemical adsorption and pore diffusion. Adsorption condition assessment, including adsorption temperature (20-120 â„ƒ) and benzene concentration in inlet phase (159.73-383.36 mg L-1), was performed. Yoon-Nelson model fitting indicated adsorption site loss at higher temperatures and reduced capture ability due to increased adsorbate molecule kinetic energy. Higher adsorbate concentrations aided adsorption molecule diffusion to biochar surface and internal pores, increasing adsorption rate and shortening equilibrium time. Overall, zinc chloride-modified biochar facilitates benzene adsorption through pore filling and π-π interactions, with pore filling as primary mechanism. Produced biochar shows excellent regeneration properties and reusability.


Subject(s)
Benzene , Chlorides , Water Pollutants, Chemical , Zinc Compounds , Zea mays , Adsorption , Water Pollutants, Chemical/chemistry , Charcoal/chemistry , Kinetics
2.
Environ Res ; 238(Pt 2): 117265, 2023 12 01.
Article in English | MEDLINE | ID: mdl-37775009

ABSTRACT

Thermal catalytic degradation of formaldehyde (HCHO) over manganese-based catalysts is garnering significant attention. In this study, both theoretical simulations and experimental methods were employed to elucidate the primary reaction pathways of HCHO on the MnO2(110) surface. Specifically, the effects of doping MnO2 with elements such as Fe, Ce, Ni, Co, and Cu on the HCHO oxidation properties were evaluated. Advanced characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS), were employed to discern the physical properties and chemical states of the active components on the catalyst surface. The comprehensive oxidation pathway of HCHO on the MnO2(110) surface includes O2 adsorption and dissociation, HCHO adsorption and dehydrogenation, CO2 desorption, H2O formation and desorption, oxygen vacancy supplementation, and other elementary reactions. The pivotal rate-determining step was identified as the hydrogen migration process, characterized by an energy barrier of 234.19 kJ mol-1. Notably, HCHOO and *CHOO emerged as crucial intermediates during the reaction. Among the doped catalysts, Fe-doped MnO2 outperformed its counterparts doped with Ce, Ni, Co, and Cu. The optimal degradation rate and selectivity were achieved at a molar ratio of Fe: Mn = 0.1. The superior performance of the Fe-doped MnO2 can be ascribed to its large specific surface area, conducive pore structure for HCHO molecular transport, rich surface-adsorbed oxygen species, and a significant presence of oxygen vacancies.


Subject(s)
Manganese , Oxides , Oxides/chemistry , Manganese Compounds/chemistry , Oxygen/chemistry , Catalysis , Formaldehyde/chemistry
3.
Environ Sci Pollut Res Int ; 30(2): 2555-2574, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35933530

ABSTRACT

In this paper, the NO-SCO (the selective catalytic oxidation of NO) experiments of single-phase Mn2O3, supported Mn2O3/Al2O3, and the Ce-doped MnxCey/Al catalyst system were carried out. The physical and chemical properties of the catalysts were analyzed by XRD, BET, XPS, SEM, O2-TPD, and H2-TPR. The effects of loading and Ce doping on catalyst activity were studied. The results show that the Mn2O3 catalyst exhibited the best activity at 300 ℃, and the NO conversion rate of Mn2O3 was 78.2%. The relative content of Oα adsorbed on the surface of the Mnx/Al catalyst decreased obviously by loading Mn2O3 on γ-Al2O3, which led to the decrease in catalyst activity. And the temperature window moved to the high-temperature region. After doping Ce, the dispersion of Mn enhanced, and the relative content of oxygen Oα adsorbed on the surface increased. The low-temperature activity and fluidity of oxygen in catalysts were improved. Among them, the Mn0.2Ce0.08/Al catalyst obtained a high specific surface area, good pore structure, large oxygen storage capacity, and excellent surface oxygen species. The corresponding NO conversion rate reached 83.5% at 290 ℃. Then, the effects of operating parameters such as space velocity, NO concentration, and O2 content on the catalytic activity of Mn0.2Ce0.08/Al were discussed. The experimental results show that the NO conversion rate of Mn0.2Ce0.08/Al decreased with increasing NO concentration and space velocity. The O2 content had a positive effect on the catalytic activity of the catalyst. However, the NO conversion rate tended to be stable due to the saturation of oxygen adsorbed on the catalyst. Through cycling experiments, we found that Mn2O3, Mn0.2/Al, and Mn0.2Ce0.08/Al catalysts showed good oxidation stabilities for NO oxidation. The evaluation of the water and sulfur resistance of the catalyst shows that the toxicity of SO2 was reduced by the aqueous atmosphere to a certain extent. Through the structural optimization of the basic model and the calculation of the NO-SCO reaction path, the results show that the NO-SCO reaction on the Mn2O3 (110) face followed the ER mechanism more. For the Mn2O3/Al2O3 (110) surface, the LH-MvK hybrid mechanism can greatly reduce the desorption energy barrier of the reaction intermediates, which is more favorable for the NO-SCO reaction. The catalytic mechanisms of the MnxCey/Al catalysts require further in-depth research.


Subject(s)
Cold Temperature , Water , Temperature , Oxidation-Reduction , Oxygen , Catalysis
4.
Environ Int ; 166: 107346, 2022 08.
Article in English | MEDLINE | ID: mdl-35724538

ABSTRACT

Compared to landfill, MSW incineration (MSWI) not only eliminates its innate secondary pollution and land occupation, but also yields a net emission reduction. Regretfully, MSWI produces hazardous incineration fly ash (IFA) enriched with potentially toxic elements and dioxins. Given these, a harmless integrated scenario of co-disposal and resource reutilization of MSW and its hazardous IFA is proposed and subjected to technical and economic analysis. It introduces an IFA melting furnace, as an onsite modular integration, which serves as a bridge between the MSW incinerator and the commercial rock wool production line. The incinerator burns MSW for heating and electricity supply. The melting furnace further burns out the highly toxic dioxins adsorbed on IFA, as well as solidifying the potentially toxic elements into the molten slag, which substitutes for basalt as raw materials used for high value-added rock wool production. That achieves collaborative reduction, stabilization, harmlessness and resource reutilization of MSW as an energy source, and its IFA as energy-saving materials, as well as a net carbon emission reduction and high economicbenefits. Even more exciting, as opposed to the serious losses of the other existing scenarios, it is profitable even without the feed-in tariff and fiscal subsidy, both that are the dominating income source of other scenarios including conventional MSWI & IFA landfill and demonstration MSWI with IFA melting & landfill. Discounted Cash Flow technique shows that the profit is âˆ¼ 9.2 RMB per ton of MSW, and it increases with insulation price, feed-in tariff, and fiscal subsidy. With the feed-in tariff and fiscal subsidy, the existing two scenarios and the proposed harmless integrated scenario can produce revenue of 103.8, 98.1-110.5, and 145.0 RMB per ton of MSW, respectively. Nonetheless, several challenges are posed for future industrial applications, such as liquid slag discharge, unstable combustion and possible environmental issues.


Subject(s)
Burns , Dioxins , Metals, Heavy , Refuse Disposal , Humans , Coal Ash , Incineration/methods , Solid Waste , Carbon , Refuse Disposal/methods , Metals, Heavy/analysis
5.
Sci Rep ; 10(1): 21276, 2020 12 04.
Article in English | MEDLINE | ID: mdl-33277540

ABSTRACT

Up to 30% of all breast cancer cases may be inherited and up to 85% of those may be due to segregation of susceptibility genes with low and moderate risk [odds ratios (OR) ≤ 3] for (mostly peri- and post-menopausal) breast cancer. The majority of low/moderate-risk genes, particularly those with minor allele frequencies (MAF) of < 30%, have not been identified and/or validated due to limitations of conventional association testing approaches, which include the agnostic nature of Genome Wide Association Studies (GWAS). To overcome these limitations, we used a hypothesis-driven integrative genomics approach to test the association of breast cancer with candidate genes by analyzing multi-omics data. Our candidate-gene association analyses of GWAS datasets suggested an increased risk of breast cancer with ERCC6 (main effect: 1.29 ≤ OR ≤ 2.91, 0.005 ≤ p ≤ 0.04, 11.8 ≤ MAF ≤ 40.9%), and implicated its interaction with ERCC8 (joint effect: 3.03 ≤ OR ≤ 5.31, 0.01 ≤ pinteraction ≤ 0.03). We found significant upregulation of ERCC6 (p = 7.95 × 10-6) and ERCC8 (p = 4.67 × 10-6) in breast cancer and similar frequencies of ERCC6 (1.8%) and ERCC8 (0.3%) mutations in breast tumors to known breast cancer susceptibility genes such as BLM (1.9%) and LSP1 (0.3%). Our integrative genomics approach suggests that ERCC6 may be a previously unreported low- to moderate-risk breast cancer susceptibility gene, which may also interact with ERCC8.


Subject(s)
Breast Neoplasms/genetics , Carcinoma, Ductal, Breast/genetics , DNA Helicases/genetics , DNA Repair Enzymes/genetics , Poly-ADP-Ribose Binding Proteins/genetics , Transcription Factors/genetics , Female , Genome-Wide Association Study , Humans
6.
Criminology ; 54(1): 30-55, 2016 Feb.
Article in English | MEDLINE | ID: mdl-28936228

ABSTRACT

This article provides a demographic exposition of the changes in the U.S prison population during the period of mass incarceration that began in the late twentieth century. By drawing on data from the Survey of Inmates in State Correctional Facilities (1974-2004) for inmates 17-72 years of age (N = 336), we show that the age distribution shifted upward dramatically: Only 16 percent of the state prison population was 40 years old or older in 1974; by 2004, this percentage had doubled to 33 percent with the median age of prisoners rising from 27 to 34 years old. By using an estimable function approach, we find that the change in the age distribution of the prison population is primarily a cohort effect that is driven by the "enhanced" penal careers of the cohorts who hit young adulthood-the prime age of both crime and incarceration-when substance use was at its peak. Period-specific factors (e.g., proclivity for punishment and incidence of offense) do matter, but they seem to play out more across the life cycles of persons most affected in young adulthood (cohort effects) than across all age groups at one point in time (period effects).

7.
Bioresour Technol ; 129: 642-5, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23317552

ABSTRACT

Based on the ash-related problems during biomass combustion, the evolution of element S, Cl, K and chemical components and ash fusion characteristics of capsicum stalks, cotton stalks and wheat stalks ashed at 1000, 1200 and 1400 °C are further studied by XRF and XRD. Cl disappears at 815 °C in the form of HCl due to the aluminosilicate of sylvite. Above 1000 °C, inorganic S is released in the form of SO2 by the silicate of K2SO4, which is the main reason that ashing ratio decreases at high temperature. Except of the evaporation of KCl and K2SO4 aerosol which cause the release of K, Cl and S, K may be also reduced by the organic decomposition and the releases of metal K and KOH. The ash fusion characteristics of biomass are mainly dependent on the high-temperature molten material built up by quartz, potassium iron oxide and silicates.


Subject(s)
Chlorine/chemistry , Coal Ash/chemistry , Incineration/methods , Plant Components, Aerial/chemistry , Potassium/chemistry , Sulfur/chemistry , Biomass , Temperature
8.
Demography ; 50(4): 1477-98, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23292639

ABSTRACT

Homeownership, a symbol of the American dream, is one of the primary ways through which families accumulate wealth, particularly for blacks and Hispanics. Surprisingly, no study has explicitly documented the segregation of minority owners and renters from whites. Using data from Census 2000, this study aims to fill this gap. Analyses here reveal that the segregation of black renters relative to whites is significantly lower than the segregation of black owners from whites, controlling for relevant socioeconomic and demographic factors, contrary to the notion that homeownership represents an endpoint in the residential assimilation process. The patterns for Hispanics and Asians conform more to expectations under the spatial assimilation model. The findings here suggest that race and ethnicity continue to be as important in shaping residential segregation as socioeconomic status, and raise concerns about the benefits of homeownership, particularly for blacks.


Subject(s)
Housing/statistics & numerical data , Minority Groups/statistics & numerical data , Racial Groups/statistics & numerical data , Residence Characteristics/statistics & numerical data , Black or African American/statistics & numerical data , Asian/statistics & numerical data , Censuses , Cities , Hispanic or Latino/statistics & numerical data , Humans , Socioeconomic Factors , United States
9.
Popul Rev ; 51(1): 85-115, 2012.
Article in English | MEDLINE | ID: mdl-26180265

ABSTRACT

The recent dramatic rise in U.S. income inequality has prompted a great deal of research on trends in overall family income and changes in sources of family income, especially among the highest income earners. However, less is known about changes in sources of income among the bottom 99% or about racial/ethnic differences in those trends. The present research contributes to the literatures on income trends and racial economic inequality by using family-level data from the 1988-2009 Current Population Survey to examine changes in overall family income and the proportion of income coming from employment, property/assets, and transfers across five different levels of family income for white-, black, and Hispanic-headed families. We find that at all income levels above the 25th percentile, employment income is by far the largest contributor to family income for all racial/ethnic groups. Employment income trended upward over the period in both real dollars and as a percentage of total family income. In this respect, white, black and Hispanic families are remarkably similar. The racial gap in total family income has remained fairly stable over the period, but this trend conceals a narrowing of racial differences in property income, mostly as a function of the decline in property income among whites, a widening of racial differences in transfer income among the bottom 25%, and a widening of racial differences in employment income, particularly at the top of the family income distribution. Income accrued from wealth is a very small component of overall family income for all three racial groups, even for the highest-income families (top 1%).

10.
J Hazard Mater ; 179(1-3): 400-8, 2010 Jul 15.
Article in English | MEDLINE | ID: mdl-20363559

ABSTRACT

Experimental characterization of the wet flue gas desulfurization process is carried out using a model limestone-hydrochloric acid reaction system, with in-situ measurement of the dissolution rate and particle size distribution. The limestone source, initial particle size distribution, working temperature and pH value are varied in large ranges. The dissolution rate is found to be higher when the average particle size is smaller, the temperature is higher, or the pH is lower. An empirical equation is established to correlate the dissolution rate with the particle size and working conditions, which agrees well with measurements. The results may be useful for providing insights to improve the efficiency of the wet flue gas desulfurization process, as well as other solid particle-liquid solution reactions.


Subject(s)
Calcium Carbonate/chemistry , Hydrochloric Acid/chemistry , Particle Size , Algorithms , Diffusion , Hydrogen-Ion Concentration , Solubility , Temperature
11.
Res Soc Stratif Mobil ; 27(4): 301-309, 2009 Dec 01.
Article in English | MEDLINE | ID: mdl-20161570

ABSTRACT

Attention has recently been focused on wealth as a source of long-term economic security and on wealth ownership as a crucial aspect of the racial economic divisions in the United States. This literature, however has been concerned primarily with the wealth gap between poor and middle-class families, and between the white and black middle class. In this paper, we investigate the incomes of families at the top and bottom of the family income distribution. We examine the sources of income and the demographic characteristics of these high-income and low-income families using family level data from the 1988-2003 Current Population Surveys.We find that, at the bottom of the distribution, transfer income is the major income source; in particular, income from social security, supplemental security, and public assistance. At the top, employment income is the largest component of family income. Non-white, female, and non-married householders are disproportionately located at the bottom of the family income distribution. These families consist of both young and old adults, with high-school educations or less, in low-level service occupations. Many are disabled, many are retired. Householders at the top of the income distribution are typically male, white, and married. Householders and spouses at the top are typically middle-age, with college educations, employed in professional service and managerial occupations.We find that wealth is not an important source of income for families at the highest percentiles. The highest income families during this period in the U.S. were not a "property elite": their income is mostly from employment. We speculate, however, that they will join the "property elite" later in the life-course as they retire and receive income from their investments.

12.
World J Surg Oncol ; 6: 18, 2008 Feb 15.
Article in English | MEDLINE | ID: mdl-18275617

ABSTRACT

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a human epithelial tumour with high prevalence amongst Chinese in Southern China and South East Asia and is associated with the Epstein-Barr virus (EBV). The viral genome harbours an oncogene, namely, the latent membrane protein 1 (LMP1) gene and known variants such as the 30-bp deletion and loss of XhoI restriction site have been found. Less is known about the relationship between these variants and the population characteristics and histological type. METHODS: In this study, the EBV LMP1 gene variants from 42 NPC and 10 non-malignant archived formalin fixed, paraffin-embedded tissues, as well as plasma from another 35 patients with nasopharyngeal carcinoma were determined by using Polymerase Chain Reaction (PCR). Statistical analysis was performed by using SPSS programme. RESULTS: LMP1 30-bp deletion was detected in 19/34 (55.9%) of NPC tissues, 7/29 (24.1%) of plasma but absent in non-malignant tissues (8/8). Coexistence of variants with and without 30bp deletion was found only in 5/29 (17.2%) plasma samples but not in NPC tissues. The loss of XhoI restriction site in LMP1 gene was found in 34/39 (87.2%) of the NPC tissues and 11/30 (36.7%) of plasma samples. None of the non-malignant nasopharyngeal tissues (8/8) harbour XhoI-loss variants. LMP1 30-bp deletion was detected in 16/18 Chinese versus 3/15 Malays and 13/16 type III (undifferentiated carcinoma) versus 1/6 type I (keratinizing squamous cell carcinoma). XhoI-loss was found in 19/19 Chinese versus 14/19 Malays and 18/18 type III (undifferentiated) versus 2/5 type I (keratinizing squamous cell carcinoma). Statistical analysis showed that these variants were associated with ethnic race (30-bp deletion, p < 0.05; XhoI-loss, p = 0.046) and histological type of NPC (30-bp deletion, p = 0.011; XhoI-loss, p = 0.006). Nineteen out of 32 NPC tissues (19/32; 59.4%) and 6/24 (25%) of plasma samples showed the coexistence of both the 30-bp deletion and the loss of XhoI restriction site. A significant relationship was found with the Chinese race but not histological type. CONCLUSION: The incidence rate of 56% for LMP1 30-bp deletion was lower compared to previously reported rates of 75-100% in NPC tissues. Coexistence of variants with and without 30-bp deletion was found only in 5/29 plasma samples. The incidence rate of XhoI restriction site loss in NPC was comparable to other studies from endemic regions such as Southern China. For the first time, the presence of LMP1 30-bp deletion or XhoI-loss was associated with the Chinese race and type III NPC. Both these variants were not found in non-malignant tissues. The influence of these variants on disease progression and outcome in Chinese and type III NPC requires further investigation.


Subject(s)
Deoxyribonucleases, Type II Site-Specific/metabolism , Gene Deletion , Herpesvirus 4, Human/genetics , Intracellular Signaling Peptides and Proteins/genetics , Nasopharyngeal Neoplasms/genetics , Viral Matrix Proteins/genetics , Adaptor Proteins, Signal Transducing , Base Sequence , Binding Sites , China/ethnology , Cytoskeletal Proteins , DNA, Viral , Female , Genetic Variation , Humans , Incidence , LIM Domain Proteins , Malaysia/epidemiology , Male , Mutation , Nasopharyngeal Neoplasms/blood , Nasopharyngeal Neoplasms/epidemiology , Pilot Projects
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 25(9): 1393-6, 2005 Sep.
Article in Chinese | MEDLINE | ID: mdl-16379273

ABSTRACT

Nitrogen functionalities of volatile of three different rank coals, namely TONGCHUAN lean coal, SHENMO bituminite and YIBIN anthracite, were studied by using Fourier transform infrared spectroscopy (FTIR) equipped with 16 m long path distance gas cell. The detection problem of low content of nitrogen in volatile was successfully solved because of the application of the long path distance gas cell. In the long path distance gas cell, the infrared penetrates the sample more times than in a normal gas cell. Results from the analysis of spectra obtained by FTIR show that there are four functionalities of nitrogen in volatile, including pyrrole-type nitrogen, pyrindine-type nitrogen, pyridine-N-oxide nitrogen, and nitrile nitrogen. Comparison of research results of nitrogen group between coal and volatile suggests that the difference in fate of nitrogen between volatile and coal results from the macromolecular nitrogen group of coal decomposition under the effect of temperature.


Subject(s)
Coal/analysis , Nitrogen/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Coal/classification , Gases/chemistry , Models, Chemical , Molecular Structure , Spectroscopy, Fourier Transform Infrared/instrumentation , Temperature , Volatilization
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