Shipborne expendable all-optical fiber ocean temperature-depth profile sensor.

Traditional electrical expendable bathythermograph (XBT) is designed to fall at a known rate based on a great deal of experiments so that the depth of the temperature profile can be inferred from the time it enters the water. Unlike the traditional electrical XBT, which derives the depth from fall-rate equations, we propose an all-optical fiber (AOF) XBT (AOF-XBT) based on cascade of two fiber Bragg gratings (FBGs). In the AOF-XBT, the depth data comes from one FBG, which responds in real time to the pressure acting on the diaphragm, and temperature data can be measured via the other FBG simultaneously. First, the pressure and temperature response characteristics of the AOF-XBT are analyzed based on a finite element method. Then, the temperature and pressure calibrations for the AOF-XBT is completed after they are packaged. Results show that the mean-temperature sensitivity of two sensors are 14.765 and 13.705 pm/°C in the range of 5°C-30°C, and the mean-pressure sensitivities are -2.75586 and -3.00472nm/MPa in the range of 0-0.6 MPa, respectively. At last, by comparing the results obtained from the AOF-XBT and the SBE 911plus CTD that tested in the sea area of Weihai, the trends of the temperature-depth profile from the two devices are consistent, which presents a new all-optical technique to provide full ocean temperature-depth profile observations.

Rapid decline in forced expiratory volume in 1 second (FEV1) and the development of bronchitic symptoms among new Chinese coal miners.

OBJECTIVE: To investigate the relationship between the development of bronchitic symptoms and the early rapid decline of forced expiratory volume in 1 second (FEV1). METHODS: A two-stage and a mixed model approach were used to analyze data from 260 newly hired Chinese coal miners who completed approximately 5 to 16 health surveys during 3 years. RESULTS: The proportion of miners with onset of bronchitic symptoms was significantly elevated after 11 months of underground mining. Miners with incident symptoms had greater declines in FEV1 compared with those who did not (-65 vs -23 mL/yr, P < 0.05). At 24 months follow-up, FEV1 had declined an average 235 mL among the 26 miners who developed bronchitic symptoms and smoked, compared with a decline of 96 mL among the 132 nonsmoking miners without symptoms. CONCLUSIONS: Among new coal miners, a sharp early decline in FEV1 is associated with the development of bronchitic symptoms.

[Early change of pulmonary ventilation in new coal miners].

OBJECTIVE: To study the early effects of coal dust on lung function in new underground coal miners. METHODS: Two hundred and eighty-seven male miners were selected from new employees at the Xuzhou Mining Group Company as study group, and 132 male students at a mining technical school were selected as control. Data collection included: individual demographic parameters, family medical history, occupational history, and smoking history, measurement of dust concentrations in work areas, and lung function tests. This prospective cohort study took place over 3 years during which time total dust and respirable dust concentrations in the new coal miners' work areas were measured twice each month. For both miner and student groups, FVC and FEV(1) were tested initially before dust exposure, and then 15 times over the 3 years. RESULTS: The average total dust and respirable dust concentrations in the miners' work areas were 23.8 mg/m(3) and 8.9 mg/m(3) respectively, which greatly exceeded national health criteria. During the first year of dust exposure, the miners's average FVC was higher than that of the controls (5.19 L vs 4.92 L, P < 0.01). During the 2nd and 3rd year the difference in average FVC between miners and control group was not significant (5.14 L vs 5.12 L, P > 0.05). Before dust exposure, the miners' FEV(1) was significantly higher than that of the control group (4.48 L vs 4.28 L). In the miners group, FEV(1) declined rapidly during the first year following dust exposure (from 4.48 L to 4.25 L), and in the 2nd and the 3rd year the average FEV(1) of the miners was significantly lower than that of controls (4.34 L vs 4.56 L, P < 0.01), although there were some fluctuations during the follow-up period. Overall, the average FEV(1) of miners group showed a significant decline during the study. There were significant correlations between FVC or FEV(1) and age, height, weight, and smoking. The three-year total loss of FVC and FEV(1) in smoking miners (154 ml, 184 ml) were greater than in non-smoking miners (83 ml, 91 ml). CONCLUSION: There are apparent effects of coal dust on lung function in new underground coal miners, with FEV(1) being more impacted than FVC. Smoking may aggravate the effect of dust exposure on reducing lung function.

[Analyses of 1003 death cases of pneumoconiosis from Xuzhou coal mines].

In order to investigate the general rules concerning attack, development and death of pneumoconiosis for providing scientific evidences for preventing, 1003 death cases of pneumoconiosis from Xuzhou coal mine factory were analyzed. Results showed that: (1) The death causes was in the sequence of pneumoconiosis, lung tuberculosis, chronic cor pulmonale, pulmonary carcinoma, etc., and changed into pneumoconiosis, chronic cor pulmonale, pulmonary carcinoma, cerebrovascular accident, etc. since 1990s. Lung tuberculosis would no longer be the main death cause of pneumoconiosis; (2) The accumulative death percentage of the death cases about pneumoconiosis was correlated to the length of dust exposure. The accumulative death percentage increased rapidly in a beeline within 5 to 20 years; (3) The length of service of episode and mean life of digging or mining workers were significantly shorter than that of others (P < 0.01); (4) The mean life and the course of diseases became more and more longer than ever since 1970s. Therefore, it can be concluded that the key for preventing and controlling pneumoconiosis was to decrease the concentration of dust in workplace and to limit the length of service of dust exposure.

[Analysis on pneumoconiosis characteristic and its prediction in one coal mine].

OBJECTIVE: We aimed to investigate the characteristic of pneumoconiosis on coal miners and provide scientific evidences for its prevention. METHODS: To analyze the data of pneumoconiosis from one coal mine with the historical study and to predict its development tendency by the grey model of GM (1,1). RESULTS: (1) The year of work experience of pneumoconiosis (stage I) was 19.9 years and the age of its diagnosis (stage I) was 51.4 years. There was an obvious tendency that they became longer with years' back-shift. (2) During near forty years, the progression rates of pneumoconiosis from stage I to II and II to III were 13.6% and 11.2%, and the mean time was 8.3 and 8.1 years, respectively. It was obvious that the progression rate decreased gradually and the span prolonged with years' back-shift. (3) The complication rate of pneumoconiosis with lung tuberculosis was 12.5% and it increased with the progression of pneumoconiosis. The rate in dead cases was significantly higher than that in live cases (P < 0.01). (4) The sequence of death causes was pneumoconiosis (20.0%), lung tuberculosis (18.3%), chronic cor pulmonale (17.9%), and pulmonary carcinoma (9.0%), et al. (5) It was predicted that there would be 28 new cases every year during 2001-2020 years and the accumulated numbers of pneumoconiosis would be 2854 cases in 2020, but with a downward trends in the prevalence of -1.7%. CONCLUSION: It was suggested that the prevalence of pneumoconiosis should decrease obviously. However, it still remains a challenge about the task of effectively preventing and curing it or its complication.