Under earthquake action, different site conditions have a notable impact on the dynamic response of high-speed railway bridges after earthquakes, which in turn poses a threat to the running stability of trains in the ...Under earthquake action, different site conditions have a notable impact on the dynamic response of high-speed railway bridges after earthquakes, which in turn poses a threat to the running stability of trains in the post-earthquake period. Therefore, establishing a calculation method for the post-earthquake train speed threshold that considers the influence of different site characteristics is of great engineering significance. Taking the CRTS Ⅲ slab track as the research object, this study is based on the track irregularity root mean square rate(TRR), which the authors proposed earlier to quantify the track regularity level. Using the nonlinear least squares fitting method, the mapping relationship between the TRR and the postearthquake train running performance indicators on bridges is established. Furthermore, the influence of laws governing site categories and train speeds on post-earthquake train running performance on bridges is analyzed, and a train speed threshold for bridges based on running performance under random site conditions is proposed. The research results indicate that all train running performance indicators increase significantly with the increase of train operating speed;different site categories have a significant impact on post-earthquake track residual deformation and train running stability. The greater the amplitude of postearthquake track alignment residual deformation, the lower the threshold for the stable running speed of trains after the earthquake, with the speed threshold decreasing by up to 20%. The research outcomes can provide technical references for the post-earthquake safe operation and maintenance of high-speed railway bridges under complex site conditions, as well as the formulation of targeted train speed control schemes.展开更多
A total of 60 crossbred(Large White×Landrace) pigs of halothane genotype NN(castrated males and females) were allotted to three treatments:3 h lairage with toys,3 h lairage and 0 h lairage in a randomized complet...A total of 60 crossbred(Large White×Landrace) pigs of halothane genotype NN(castrated males and females) were allotted to three treatments:3 h lairage with toys,3 h lairage and 0 h lairage in a randomized complete block design and used to evaluate the influence of lairage conditions on behavior, biochemical indicators and meat quality for finishing pigs at slaughter.Behavior of the pigs was scored subjectively during lairage.Blood samples were taken at exsanguination s to measure blood temperature, plasma Cortisol,ACTH,glucose,lactate,plasma enzymes and hematological indices.Post-mortem meat quality measurements included muscle colour value(MCV),electrical conductivity(EC),pH at 45 min and 24 h from Longissimus thoracis(LM) and Semimembranosus(SM) mucles and drip loss from LM. The results showed that 3 h lairage group with toys demonstrated significantly improved behavior than the group without toys at 3 sampling times.All the pigs showed increasing calmness as the time of lairage progressed.The omission of lairage increased plasma Cortisol,ACTH,glucose and lactate(P【0.05),and decreased plasma lactate dehydrogenase(LDH),and creatine kinase(CK)(P【0.05).No biochemical index was influenced by the presence or absence of toys during lairage(P【0.05).Muscle colour value, electrical conductivity,pH at 45 min and 24 h from LM and SM and drip loss were not affected by any treatment(P【0.05).Pigs provided 3 h lairage,with or without toys,exhibited lower red blood cell(RBC), hemoglobin(HGB),and haematocrit(HCT) when compared to 0 h lairage.3 h lairage with or without toys resulted in higher white blood cell(WBC) and lymphocyte(W-SCC) levels than 0 h lairage.None of the hemocytic indices in pigs given lairage was affected by the presence or absence of toys.We conclude from this pilot study that in local commercial conditions,from the point of view of animal welfare and meat quality,lairage time of 3 h after short travel was beneficial.Pigs resting showed increased relief from stress and a recovery in immune competence.Holding pigs in lairage with toys for a few hours after arrival at the abattoir may be beneficial for the animal’s well-being.展开更多
Prognostics and Health Management(PHM) has become a very important tool in modern commercial aircraft. Considering limited built-in sensing devices on the legacy aircraft model,one of the challenges for airborne syste...Prognostics and Health Management(PHM) has become a very important tool in modern commercial aircraft. Considering limited built-in sensing devices on the legacy aircraft model,one of the challenges for airborne system health monitoring is to find an appropriate health indicator that is highly related to the actual degradation state of the system. This paper proposed a novel health indicator extraction method based on the available sensor parameters for the health monitoring of Air Conditioning System(ACS) of a legacy commercial aircraft model. Firstly, a specific Airplane Condition Monitoring System(ACMS) report for ACS health monitoring is defined. Then a non-parametric modeling technique is adopted to calculate the health indicator based on the raw ACMS report data. The proposed method is validated on a single-aisle commercial aircraft widely used for short and medium-haul routes, using more than 6000 ACMS reports collected from a fleet of aircraft during one year. The case study result shows that the proposed health indicator can effectively characterize the degradation state of the ACS, which can provide valuable information for proactive maintenance plan in advance.展开更多
Recently there have been two causal modelling approaches to indicative conditionals,i.e.extrapolationist(Deng&Lee,2021)and filterist(Liang&Wang,2022),although they all take an interventionist position on subju...Recently there have been two causal modelling approaches to indicative conditionals,i.e.extrapolationist(Deng&Lee,2021)and filterist(Liang&Wang,2022),although they all take an interventionist position on subjunctive conditionals.Motivated by the so-called OK pairs,they try to provide a convincing explanation of the intuition underlying the OK pairs.As far as we know,what they have done is to provide not only an explanation of the OK pairs,but also a way of distinguishing between indicative and subjunctive conditionals.Although we agree with their success in explaining the OK pairs within a causal modelling framework,we argue that their ways of distinguishing between indicative and subjunctive conditionals fail.Instead,we argue that their approaches can be used to distinguish between two readings of conditionals,the epistemic reading and the ontic reading.which can be applied to both indicative and subjunctive conditionals.We conclude by arguing that these two readings are related to two approaches to asking and answering causal questions:the“auses-of-effects"approach and the"effects-of-causes"approach.展开更多
The effect of packaging materials and lighting conditions on quality of extra virgin olive oil （EVOO） was investigated during six months. The results highlighted an influence of light and type of packaging material ...The effect of packaging materials and lighting conditions on quality of extra virgin olive oil （EVOO） was investigated during six months. The results highlighted an influence of light and type of packaging material on EVOO-quality with storage time. At shelf, all packages maintained EVOO at the end of storage in terms of acidity, peroxide value, K232, while K270 exceeded limit of EVOO in glass and PET-stored oil. Loss of phenols was the highest in glass-stored oil and the lowest in high-density polyethylene （HDPE）-stored oil. In terms of sensory evaluation, glass-stored oil lost EVOO grade after three months and its edible compliance after six months, while HDPE-stored oil maintained EVOO grade 90 days and was virgin after six months. In extended lighting, acidity, peroxide value and K232 did not exceed EVOO grade, while K270 exceeded EVOO grade after 30 days in glass and polyethylene terephthalate （PET）-stored oil and after 90 days in HDPE. The loss of phenols was the largest in glass and smallest in HDPE-stored oil. Glass stored-oil lost organoleptic edible compliance before 90 days, while that in PET was virgin at 90 days and that in HDPE maintained EVOO quality 90 days. At the end of experiment, oils in all packages were not edible. In dark, all packages maintained oil in EVOO quality in terms of all indices. The loss of phenols was marginal but was the least in glass and the highest in HDPE. It was concluded that HDPE bottles conserve stored olive oil at shelf or illumination better than PET or glass, while in dark, glass was superior over plastic.展开更多
Radiolarites have an important role in the reconstruction of the paleogeography, bathymetry and their coexistence with ophiolites gives an opportunity to determine the tectonic his- tory of collisional zones. The radi...Radiolarites have an important role in the reconstruction of the paleogeography, bathymetry and their coexistence with ophiolites gives an opportunity to determine the tectonic his- tory of collisional zones. The radiolarite units of the southwestern Neyriz are part of the Zagros ac- cretionary prism and positioned beneath the thick bedded carbonate sediments of Tarbur Forma- tion. The existing various structural elements within this unit give a unique fortunate for investiga- tion on the deformation history and studying of the kinematics of the Zagros collision zone. The nu- merous evidence show that this unit has experienced different deformation conditions during ongo- ing evolution, including ductile, brittle-ductile and brittle deformation conditions. The main strike of E-W for axial planes of folds, eastward trend and plunge of fold axes, boudins＇ neck axes and Type III of the fold interference patterns are indicators of formation and evolution of folds during tran- spressional deformation. Structural evolution of the study area has been affected by an NE-dipping subduction zone of Neo-Tethyan oceanic lithosphere below the Iranian microcontinents. These structural elements suggest that high mechanical anisotropy and two successive generations of fold- ing simultaneously with thrusting and extrusion of this unit had led to formation and evolution of this highly asymmetrical folded unit on top of the subducted oceanic crust.展开更多
High nutritional content coupled with low cost and ease of purchase justifies the frequent use of chicken eggs. Even with technological innovations in the production, storage, and distribution of eggs, food poisoning ...High nutritional content coupled with low cost and ease of purchase justifies the frequent use of chicken eggs. Even with technological innovations in the production, storage, and distribution of eggs, food poisoning continues to occur. Therefore, in the present study, we 1) evaluated the microbiological profile and the hygienic and sanitary quality of eggs commercialized in town fairs and markets and 2) verified whether there is any correlation between microbiological results and commercialization conditions. Thirty-six samples were collected from six municipalities in the region of Rec?ncavo from Bahia, Brazil. The hygienic and sanitary conditions were analyzed by quantifying the total coliforms, E. coli, mesophilic and psychrotrophic microorganisms, molds, and yeasts, and by the presence of Salmonella sp. The observational analysis showed that 91% and 68% of the samples in town fairs and markets, respectively, did not comply with the requirements of the current Brazilian legislation. There was no significant difference in the microbiological profile among samples from the fairs and markets. Several samples presented relevant significant values, indicating inadequate hygienic conditions and fecal contamination. Salmonella sp. was found in one sample. There was co-relationship between microorganism count and the variables “external dirt”, “external stains”, and “closeness to other products”, with high concentrations of total coliforms and E. coli in the non-conforming samples. Although no limits exist for mold and yeast counts, the presence of fungi makes the product unfit for consumption. Thus, the commercialization of eggs would benefit from more attention and supervision by the relevant authorities.展开更多
Condition indices study like RNA content,DNA content,RNA:DNA,RNA:protein,RNA:lipid was carried out in goby,Parachaeturichthys ocellatus from the creeks of Mumbai to assess its nutritional status in different mon...Condition indices study like RNA content,DNA content,RNA:DNA,RNA:protein,RNA:lipid was carried out in goby,Parachaeturichthys ocellatus from the creeks of Mumbai to assess its nutritional status in different months.The study was carried out from June 2010 to September 2011.The range of RNA content in male was 72-185.6μg/100 mg while in female was 82-145.46μg/100 mg.RNA content was high during spawning months.The DNA content showed slight variations with range of 22.56-39.31μg/100 mg in males and 25.20-32.52μg/100 mg in females.The range of ratio of RNA:DNA in males was 2.08-5.13 with an average of 3.74 while in female was 2.92-5.07 with an average of 3.99.The ratio above 2 indicates good condition.The RNA:protein showed an average of 0.0015 in males and 0.0017 in females while the average of RNA:lipid was 0.0176 in males and 0.0127 in females.RNA:protein and RNA:lipid showed the lowest values in post reproductive stages while it increased with the onset of reproductive cycles.The condition indices study showed that P.ocellatus was in good condition throughout the year and the creeks of Mumbai were suitable habitat for feeding and reproduction.展开更多
The article is devoted to a discussion of the possibilities of biometeorological assessment of the severity of weather conditions during the cold season.The relevance of the study is ensured not only by the fact that ...The article is devoted to a discussion of the possibilities of biometeorological assessment of the severity of weather conditions during the cold season.The relevance of the study is ensured not only by the fact that residents of a number of states,whose total number is more than 27 million people,live in these extreme climatic conditions,but also by the need to improve biometeorological approaches to assessing the impact of these conditions on the body and health of the population.This study examined biometeorological characteristics that illustrate a measure of cold stress.These include the Siple wind-chill index;Bodman winter severity index;Arnoldi weather hardness coefficient;Mountain wind chill index;weather hardness coefficient according to I.M.Osokin.The results of a comparison of winter severity assessments based on the values of the calculated Siple and Bodman indices made it possible to establish that the Bodman index is more acceptable when assessing mildly severe winters.The most adequate for assessing the“severity”of the cold period against the background of a decrease in air temperature and an increase in wind speed is the Siple index.The need to provide the countries of the world with high-quality hydrometeorological and biometeorological forecast information is justified and relevant.In this regard,these studies are very promising.展开更多
To occupy a greater market share in terminal distribution, companies are urged to make full use of cooperative coverage formed with brand effect and information sharing in the layout of pickup points. Based on the div...To occupy a greater market share in terminal distribution, companies are urged to make full use of cooperative coverage formed with brand effect and information sharing in the layout of pickup points. Based on the diversity of pickup points, the piecewise function, signal intensity function and probability function are introduced. Meanwhile, considering the effect of distance satisfaction and cooperation coverage on customer behavior, the location model of the pickup point under competitive environments is established. The genetic algorithm is used to solve the problem, and the effectiveness of the model and algorithm is verified by a case. The results show that the sensitivity of weighted demand coverages to budget decreases gradually. The maximum weighted demand coverage increases at first and then decreases with the increase of the signal threshold, and there is a positive correlation with the change of the actual demand coverage to the senior customers, but it is negatively related to the intermediate and primary customers. When the number of high-level pickup points in a competitive enterprise is small, the advantage of the target enterprise is more significant. Through comparison, the cooperative coverage model is better than the non-cooperative coverage model, in terms of the weighted demand coverage, the construction cost and the attention paid to the important customers.展开更多
The accurate and intelligent identification of the working conditions of a sucker-rod pumping system is necessary. As onshore oil extraction gradually enters its mid-to late-stage, the cost required to train a deep le...The accurate and intelligent identification of the working conditions of a sucker-rod pumping system is necessary. As onshore oil extraction gradually enters its mid-to late-stage, the cost required to train a deep learning working condition recognition model for pumping wells by obtaining enough new working condition samples is expensive. For the few-shot problem and large calculation issues of new working conditions of oil wells, a working condition recognition method for pumping unit wells based on a 4-dimensional time-frequency signature (4D-TFS) and meta-learning convolutional shrinkage neural network (ML-CSNN) is proposed. First, the measured pumping unit well workup data are converted into 4D-TFS data, and the initial feature extraction task is performed while compressing the data. Subsequently, a convolutional shrinkage neural network (CSNN) with a specific structure that can ablate low-frequency features is designed to extract working conditions features. Finally, a meta-learning fine-tuning framework for learning the network parameters that are susceptible to task changes is merged into the CSNN to solve the few-shot issue. The results of the experiments demonstrate that the trained ML-CSNN has good recognition accuracy and generalization ability for few-shot working condition recognition. More specifically, in the case of lower computational complexity, only few-shot samples are needed to fine-tune the network parameters, and the model can be quickly adapted to new classes of well conditions.展开更多
Strategic maintenance plays a key role in ensuring high availability and utilization of the haul trucks,and as equipment began to grow more complex towards the end of the 20th century,there was a need for a proactive ...Strategic maintenance plays a key role in ensuring high availability and utilization of the haul trucks,and as equipment began to grow more complex towards the end of the 20th century,there was a need for a proactive maintenance strategy,which led to the development of condition-based maintenance.Realtime condition monitoring(RTCM)is the ability to perform condition monitoring in real-time and has the ability to alert maintenance and operations of abnormal conditions.These alarms can be used as an indication leading to a problem,and if a suitable corrective action is initiated in time,it could result in significant savings of equipment downtime and repair costs.This study aims to compare some maintenance performance indicators prior to and after implementation of RTCM strategy at a mine site using some tests of statistical significance.The study also indicated the presence of seasonality in the data,and thus the data was deseasonalized and detrended prior to being subjected to the statistical tests.Finally,the results indicated that RTCM strategy has proven to be successful in improving the availability for some of the failure categories chosen in this study.展开更多
基金supported by the Science and Technology Research and Development Program Project of China Railway Group Limited (Grant No.2022-Major-17)the National Natural Science Foundation of China (Grant Nos.52578619,52178180)+2 种基金the National Key Research and Development Program of China (Grant No.2022YFC3004304)the Frontier Cross Research Project of Central South University (Grant No.2023QYJC006)the Natural Science Foundation of Hunan Province Funding Project (Grant No.2023JJ40724)。
文摘Under earthquake action, different site conditions have a notable impact on the dynamic response of high-speed railway bridges after earthquakes, which in turn poses a threat to the running stability of trains in the post-earthquake period. Therefore, establishing a calculation method for the post-earthquake train speed threshold that considers the influence of different site characteristics is of great engineering significance. Taking the CRTS Ⅲ slab track as the research object, this study is based on the track irregularity root mean square rate(TRR), which the authors proposed earlier to quantify the track regularity level. Using the nonlinear least squares fitting method, the mapping relationship between the TRR and the postearthquake train running performance indicators on bridges is established. Furthermore, the influence of laws governing site categories and train speeds on post-earthquake train running performance on bridges is analyzed, and a train speed threshold for bridges based on running performance under random site conditions is proposed. The research results indicate that all train running performance indicators increase significantly with the increase of train operating speed;different site categories have a significant impact on post-earthquake track residual deformation and train running stability. The greater the amplitude of postearthquake track alignment residual deformation, the lower the threshold for the stable running speed of trains after the earthquake, with the speed threshold decreasing by up to 20%. The research outcomes can provide technical references for the post-earthquake safe operation and maintenance of high-speed railway bridges under complex site conditions, as well as the formulation of targeted train speed control schemes.
基金supported financially by the project‘Research and Development on Technology and Key Equipment for New Type of Industrialized and Healthy Animal Husbandry'funded by the Chinese Ministry of Science and Technology(2006BAD 14B02-6)11th Five Years Key Programs for Science and Technology Development of China(2006BAD01A08-07)+1 种基金Hubei Province Key Project of Science and Technology (2006AA201B24)Wuhan City Key Project of Industrialization(200720112026)
文摘A total of 60 crossbred(Large White×Landrace) pigs of halothane genotype NN(castrated males and females) were allotted to three treatments:3 h lairage with toys,3 h lairage and 0 h lairage in a randomized complete block design and used to evaluate the influence of lairage conditions on behavior, biochemical indicators and meat quality for finishing pigs at slaughter.Behavior of the pigs was scored subjectively during lairage.Blood samples were taken at exsanguination s to measure blood temperature, plasma Cortisol,ACTH,glucose,lactate,plasma enzymes and hematological indices.Post-mortem meat quality measurements included muscle colour value(MCV),electrical conductivity(EC),pH at 45 min and 24 h from Longissimus thoracis(LM) and Semimembranosus(SM) mucles and drip loss from LM. The results showed that 3 h lairage group with toys demonstrated significantly improved behavior than the group without toys at 3 sampling times.All the pigs showed increasing calmness as the time of lairage progressed.The omission of lairage increased plasma Cortisol,ACTH,glucose and lactate(P【0.05),and decreased plasma lactate dehydrogenase(LDH),and creatine kinase(CK)(P【0.05).No biochemical index was influenced by the presence or absence of toys during lairage(P【0.05).Muscle colour value, electrical conductivity,pH at 45 min and 24 h from LM and SM and drip loss were not affected by any treatment(P【0.05).Pigs provided 3 h lairage,with or without toys,exhibited lower red blood cell(RBC), hemoglobin(HGB),and haematocrit(HCT) when compared to 0 h lairage.3 h lairage with or without toys resulted in higher white blood cell(WBC) and lymphocyte(W-SCC) levels than 0 h lairage.None of the hemocytic indices in pigs given lairage was affected by the presence or absence of toys.We conclude from this pilot study that in local commercial conditions,from the point of view of animal welfare and meat quality,lairage time of 3 h after short travel was beneficial.Pigs resting showed increased relief from stress and a recovery in immune competence.Holding pigs in lairage with toys for a few hours after arrival at the abattoir may be beneficial for the animal’s well-being.
基金supported by the National Natural Science Foundation of China (61403198)the Jiangsu Province Natural Science Foundation of China (BK20140827)China Postdoctoral Science Foundation (2015M581792)
文摘Prognostics and Health Management(PHM) has become a very important tool in modern commercial aircraft. Considering limited built-in sensing devices on the legacy aircraft model,one of the challenges for airborne system health monitoring is to find an appropriate health indicator that is highly related to the actual degradation state of the system. This paper proposed a novel health indicator extraction method based on the available sensor parameters for the health monitoring of Air Conditioning System(ACS) of a legacy commercial aircraft model. Firstly, a specific Airplane Condition Monitoring System(ACMS) report for ACS health monitoring is defined. Then a non-parametric modeling technique is adopted to calculate the health indicator based on the raw ACMS report data. The proposed method is validated on a single-aisle commercial aircraft widely used for short and medium-haul routes, using more than 6000 ACMS reports collected from a fleet of aircraft during one year. The case study result shows that the proposed health indicator can effectively characterize the degradation state of the ACS, which can provide valuable information for proactive maintenance plan in advance.
基金supported by China’s MOE project of Key Research Institute of Humanities and Social Sciences at Universities(22JJD720021)the project of Shandong University(11090087395308).
文摘Recently there have been two causal modelling approaches to indicative conditionals,i.e.extrapolationist(Deng&Lee,2021)and filterist(Liang&Wang,2022),although they all take an interventionist position on subjunctive conditionals.Motivated by the so-called OK pairs,they try to provide a convincing explanation of the intuition underlying the OK pairs.As far as we know,what they have done is to provide not only an explanation of the OK pairs,but also a way of distinguishing between indicative and subjunctive conditionals.Although we agree with their success in explaining the OK pairs within a causal modelling framework,we argue that their ways of distinguishing between indicative and subjunctive conditionals fail.Instead,we argue that their approaches can be used to distinguish between two readings of conditionals,the epistemic reading and the ontic reading.which can be applied to both indicative and subjunctive conditionals.We conclude by arguing that these two readings are related to two approaches to asking and answering causal questions:the“auses-of-effects"approach and the"effects-of-causes"approach.
文摘The effect of packaging materials and lighting conditions on quality of extra virgin olive oil （EVOO） was investigated during six months. The results highlighted an influence of light and type of packaging material on EVOO-quality with storage time. At shelf, all packages maintained EVOO at the end of storage in terms of acidity, peroxide value, K232, while K270 exceeded limit of EVOO in glass and PET-stored oil. Loss of phenols was the highest in glass-stored oil and the lowest in high-density polyethylene （HDPE）-stored oil. In terms of sensory evaluation, glass-stored oil lost EVOO grade after three months and its edible compliance after six months, while HDPE-stored oil maintained EVOO grade 90 days and was virgin after six months. In extended lighting, acidity, peroxide value and K232 did not exceed EVOO grade, while K270 exceeded EVOO grade after 30 days in glass and polyethylene terephthalate （PET）-stored oil and after 90 days in HDPE. The loss of phenols was the largest in glass and smallest in HDPE-stored oil. Glass stored-oil lost organoleptic edible compliance before 90 days, while that in PET was virgin at 90 days and that in HDPE maintained EVOO quality 90 days. At the end of experiment, oils in all packages were not edible. In dark, all packages maintained oil in EVOO quality in terms of all indices. The loss of phenols was marginal but was the least in glass and the highest in HDPE. It was concluded that HDPE bottles conserve stored olive oil at shelf or illumination better than PET or glass, while in dark, glass was superior over plastic.
基金supported by University of Sistan and Baluchestan and the Shiraz University Research Council (SURC)
文摘Radiolarites have an important role in the reconstruction of the paleogeography, bathymetry and their coexistence with ophiolites gives an opportunity to determine the tectonic his- tory of collisional zones. The radiolarite units of the southwestern Neyriz are part of the Zagros ac- cretionary prism and positioned beneath the thick bedded carbonate sediments of Tarbur Forma- tion. The existing various structural elements within this unit give a unique fortunate for investiga- tion on the deformation history and studying of the kinematics of the Zagros collision zone. The nu- merous evidence show that this unit has experienced different deformation conditions during ongo- ing evolution, including ductile, brittle-ductile and brittle deformation conditions. The main strike of E-W for axial planes of folds, eastward trend and plunge of fold axes, boudins＇ neck axes and Type III of the fold interference patterns are indicators of formation and evolution of folds during tran- spressional deformation. Structural evolution of the study area has been affected by an NE-dipping subduction zone of Neo-Tethyan oceanic lithosphere below the Iranian microcontinents. These structural elements suggest that high mechanical anisotropy and two successive generations of fold- ing simultaneously with thrusting and extrusion of this unit had led to formation and evolution of this highly asymmetrical folded unit on top of the subducted oceanic crust.
文摘High nutritional content coupled with low cost and ease of purchase justifies the frequent use of chicken eggs. Even with technological innovations in the production, storage, and distribution of eggs, food poisoning continues to occur. Therefore, in the present study, we 1) evaluated the microbiological profile and the hygienic and sanitary quality of eggs commercialized in town fairs and markets and 2) verified whether there is any correlation between microbiological results and commercialization conditions. Thirty-six samples were collected from six municipalities in the region of Rec?ncavo from Bahia, Brazil. The hygienic and sanitary conditions were analyzed by quantifying the total coliforms, E. coli, mesophilic and psychrotrophic microorganisms, molds, and yeasts, and by the presence of Salmonella sp. The observational analysis showed that 91% and 68% of the samples in town fairs and markets, respectively, did not comply with the requirements of the current Brazilian legislation. There was no significant difference in the microbiological profile among samples from the fairs and markets. Several samples presented relevant significant values, indicating inadequate hygienic conditions and fecal contamination. Salmonella sp. was found in one sample. There was co-relationship between microorganism count and the variables “external dirt”, “external stains”, and “closeness to other products”, with high concentrations of total coliforms and E. coli in the non-conforming samples. Although no limits exist for mold and yeast counts, the presence of fungi makes the product unfit for consumption. Thus, the commercialization of eggs would benefit from more attention and supervision by the relevant authorities.
文摘Condition indices study like RNA content,DNA content,RNA:DNA,RNA:protein,RNA:lipid was carried out in goby,Parachaeturichthys ocellatus from the creeks of Mumbai to assess its nutritional status in different months.The study was carried out from June 2010 to September 2011.The range of RNA content in male was 72-185.6μg/100 mg while in female was 82-145.46μg/100 mg.RNA content was high during spawning months.The DNA content showed slight variations with range of 22.56-39.31μg/100 mg in males and 25.20-32.52μg/100 mg in females.The range of ratio of RNA:DNA in males was 2.08-5.13 with an average of 3.74 while in female was 2.92-5.07 with an average of 3.99.The ratio above 2 indicates good condition.The RNA:protein showed an average of 0.0015 in males and 0.0017 in females while the average of RNA:lipid was 0.0176 in males and 0.0127 in females.RNA:protein and RNA:lipid showed the lowest values in post reproductive stages while it increased with the onset of reproductive cycles.The condition indices study showed that P.ocellatus was in good condition throughout the year and the creeks of Mumbai were suitable habitat for feeding and reproduction.
文摘The article is devoted to a discussion of the possibilities of biometeorological assessment of the severity of weather conditions during the cold season.The relevance of the study is ensured not only by the fact that residents of a number of states,whose total number is more than 27 million people,live in these extreme climatic conditions,but also by the need to improve biometeorological approaches to assessing the impact of these conditions on the body and health of the population.This study examined biometeorological characteristics that illustrate a measure of cold stress.These include the Siple wind-chill index;Bodman winter severity index;Arnoldi weather hardness coefficient;Mountain wind chill index;weather hardness coefficient according to I.M.Osokin.The results of a comparison of winter severity assessments based on the values of the calculated Siple and Bodman indices made it possible to establish that the Bodman index is more acceptable when assessing mildly severe winters.The most adequate for assessing the“severity”of the cold period against the background of a decrease in air temperature and an increase in wind speed is the Siple index.The need to provide the countries of the world with high-quality hydrometeorological and biometeorological forecast information is justified and relevant.In this regard,these studies are very promising.
基金The National Social Science Foundation of China(No.16CGL018)
文摘To occupy a greater market share in terminal distribution, companies are urged to make full use of cooperative coverage formed with brand effect and information sharing in the layout of pickup points. Based on the diversity of pickup points, the piecewise function, signal intensity function and probability function are introduced. Meanwhile, considering the effect of distance satisfaction and cooperation coverage on customer behavior, the location model of the pickup point under competitive environments is established. The genetic algorithm is used to solve the problem, and the effectiveness of the model and algorithm is verified by a case. The results show that the sensitivity of weighted demand coverages to budget decreases gradually. The maximum weighted demand coverage increases at first and then decreases with the increase of the signal threshold, and there is a positive correlation with the change of the actual demand coverage to the senior customers, but it is negatively related to the intermediate and primary customers. When the number of high-level pickup points in a competitive enterprise is small, the advantage of the target enterprise is more significant. Through comparison, the cooperative coverage model is better than the non-cooperative coverage model, in terms of the weighted demand coverage, the construction cost and the attention paid to the important customers.
基金supported in part by the National Natural Science Foundation of China under Grant U1908212,62203432 and 92067205in part by the State Key Laboratory of Robotics of China under Grant 2023-Z03 and 2023-Z15in part by the Natural Science Foundation of Liaoning Province under Grant 2020-KF-11-02.
文摘The accurate and intelligent identification of the working conditions of a sucker-rod pumping system is necessary. As onshore oil extraction gradually enters its mid-to late-stage, the cost required to train a deep learning working condition recognition model for pumping wells by obtaining enough new working condition samples is expensive. For the few-shot problem and large calculation issues of new working conditions of oil wells, a working condition recognition method for pumping unit wells based on a 4-dimensional time-frequency signature (4D-TFS) and meta-learning convolutional shrinkage neural network (ML-CSNN) is proposed. First, the measured pumping unit well workup data are converted into 4D-TFS data, and the initial feature extraction task is performed while compressing the data. Subsequently, a convolutional shrinkage neural network (CSNN) with a specific structure that can ablate low-frequency features is designed to extract working conditions features. Finally, a meta-learning fine-tuning framework for learning the network parameters that are susceptible to task changes is merged into the CSNN to solve the few-shot issue. The results of the experiments demonstrate that the trained ML-CSNN has good recognition accuracy and generalization ability for few-shot working condition recognition. More specifically, in the case of lower computational complexity, only few-shot samples are needed to fine-tune the network parameters, and the model can be quickly adapted to new classes of well conditions.
文摘Strategic maintenance plays a key role in ensuring high availability and utilization of the haul trucks,and as equipment began to grow more complex towards the end of the 20th century,there was a need for a proactive maintenance strategy,which led to the development of condition-based maintenance.Realtime condition monitoring(RTCM)is the ability to perform condition monitoring in real-time and has the ability to alert maintenance and operations of abnormal conditions.These alarms can be used as an indication leading to a problem,and if a suitable corrective action is initiated in time,it could result in significant savings of equipment downtime and repair costs.This study aims to compare some maintenance performance indicators prior to and after implementation of RTCM strategy at a mine site using some tests of statistical significance.The study also indicated the presence of seasonality in the data,and thus the data was deseasonalized and detrended prior to being subjected to the statistical tests.Finally,the results indicated that RTCM strategy has proven to be successful in improving the availability for some of the failure categories chosen in this study.
