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Using longitudinal data from the 2014–2018 China Family Panel Studies, we investigate the impact of internet use (IU) on fertility among reproductive-age women. We find that IU reduces the number of children born, with more pronounced effects among those with a moderate level of education, those aged 16–19, rural residents, and those who are married. These results are robust to alternative IU measures and a series of estimation approaches that control for endogeneity. IU participation affects the number of children born through decreased marital satisfaction, changed attitudes toward traditional gender roles, a reduction in the importance placed on ancestral lines, deteriorated health and reduced fertility preferences.

The US produce industry faces intensifying competition from imports, particularly those from Mexico, the largest exporter of produce to the United States. Fresh produce imports from Mexico have grown dramatically in recent years. This study examines the impact of increasing fresh tomato imports from Mexico on market price and revenue of US growers. Results show that tomato prices are highly sensitive to supply, suggesting a saturated market. Imports from Mexico have significant negative impacts on the prices of US domestic tomatoes. A scenario of 50% increase in tomato imports from Mexico could result in a $252 million (27%) revenue loss for American growers, thus posing great challenges to the sustainability of the declining US tomato industry.

Nitrile rubber O-rings seals for packaging barrel was stored in China tropical marine atmosphere environments for 10 years, and then the sealing function of nitrile rubber O-ring was failed. By comparing the molecular structure, cross-link density, thermal decomposition, content of elements and chemical functional groups of the original nitrile rubber seals, the surface and interior of nitrile rubber seals storage for 10 years, a long-term natural failure mechanism was studied. The results showed that: the surface content of dibutyl phthalate and dibutyl sebacate, the surface carbonyl peak height and the surface content of oxygen element were higher than that in internal; the surface cross-link density was lower than that in internal but still higher than in original sample; and surface carbon- to-oxygen ratio were lower than that in internal and original sample. After aging for 10 years, the weight loss of plasticizer decreased, and the main chain content increased. It can be inferred that nitrile rubber mainly undergoes oxygen-absorbing cross-linking reaction to form carboxylic acids and esters, which is accompanied by the migration and enrichment of two plasticizers to the surface, causing reductions in elasticity and elasticity. The residual permanent compression set was lower than the design critical value, and the sealing function for the packaging barrel was lost, and a leak occurred.

Welding-brazing method is widely used for dissimilar metals welding. However, it is becoming increasingly difficult to further improve the connection strength by controlling the formation of the transition layer. In this study, an innovative welding method referred to as adjacent welding was addressed, which greatly improved the tensile strength of Ti/Cu dissimilar joint. The strength of new joint could reach up to 89% that of copper base metal, compared to the use of a traditional welding-brazing method which strength coefficient is within the limit of 70%. In order to determine the strengthening mechanism of adjacent welding, optical microscopy, SEM, EDS and XRD were applied for the analysis of microstructure and phase structure. Furthermore, tensile strength was also tested. The results show that due to the process of remelting and reverse solidification of intermetallic compounds (IMCs) layer, a less complex and thinner IMCs layer was formed and TiCu (553 HV) with high embrittlement existing in the front of titanium substrate was changed into Ti2Cu (442 HV). Performances of joints were optimized by these changes. An interpretation module was presented for the mechanism. Keywords: Welding-brazing, Adjacent welding, Dissimilar welding joints, Intermetallic compounds

Presentation18549

Presentation ID 16422

Presentation ID 16112

This article analyzes issues related to the U.S. farm workers’ utilization to health care services and their specific choices among health care provider and health bill payment method options. Our findings validate the significant influence of health insurance coverage on health care access, and emphasize the reality of constrained access due to federal regulations, among other factors, prevalent among immigrant farm worker groups, who have relatively lower probability of using health care than citizen farm workers. Moreover, as most farm workers patronize private clinics and community health centers, they usually are also left only with the option to settle health care bills with out-of-pocket funds.

In addition to direct compensation (salaries and bonuses), fringe benefits such as employer-provided health insurance (EPHI) may also influence an individual’s decisions on actual and expected employment duration. This study analyzes the potential of EPHI in job retention among documented and undocumented farm workers in the United States at a time period when the farm sector is experiencing labor shortage crisis attributed to stricter immigration controls. In this study, farm worker-level data was preprocessed using Coarsened Exact Matching and analyzed under an ordered probit model. The results indicate that documented farm workers are generally responsive to EPHI in terms of both their actual employment duration and subjective working expectations. However, the EPHI did not significantly influence the subjective work expectations of undocumented farm workers. Moreover, the results imply that EPHI could not possibly be an effective tool for retaining undocumented workers on the farm once they are legalized.

Changes in agricultural population can significantly influence the progress of mechanization, which provides efficient momentum to the further development of agriculture. We examine the effect of the declining agricultural population on mechanization and determine the variables that have decisive power over mechanical adoption decisions. This analysis of a panel data of top six out-migration provinces in China under a fixed effect model, we find that the overly fast and unusual decline in agricultural population actually slowed down the progress of mechanization, and the many years of large scale out-migration encouraged by government actually jeopardized sustainable agricultural development. Results underscore the need for considerable attention on the growth of annual farm incomes and agricultural products import that could have substantial effects on agricultural mechanization decisions.