Elements can be classified into metals,nonmetals,or metalloids based on their chemical and physical properties.Precious metals are rare and expensive.There are ten known precious metals,three of which are of interest ...Elements can be classified into metals,nonmetals,or metalloids based on their chemical and physical properties.Precious metals are rare and expensive.There are ten known precious metals,three of which are of interest to investors,silver,gold,and platinum.The goal is to find physical methods to identify the presence of precious metals,silver,and gold in the metal components of the computer motherboard,and to confirm its presence by chemical methods for its use and its selling to the jewelry industry after it is physically separated from the computer motherboards.Physical and chemical tests were identified.Physical tests include inscription test,magnet test and specific gravity test for both silver and gold metal pieces and chemical tests include bleach test,nitric acid test,test karat solution kit,and jewelry test kits.展开更多
[Objective] The paper was to isolate and identify probiotics in the intestine of laying hens. [Method] The intestinal probiotics in laying hens at peak period were isolated using conventional separation methods; the p...[Objective] The paper was to isolate and identify probiotics in the intestine of laying hens. [Method] The intestinal probiotics in laying hens at peak period were isolated using conventional separation methods; the physical and chemical properties of target strains and in vitro antibacterial effects were measured. Moreover, the safety test of chicks was conducted. [Result] Four strains of lactobacillus were isolated from the jejunum of laying hens, including Lactobacillus plantarum, Bacillus acidophilus, L. delbrueckii subsp. Delbrueckii and L. delbrueckii subsp. Lactis, and their inhibition zone diameters were 18.30, 16.07, 11.45, 17.26 mm, respectively. One strain of Lactobacillus, L. brevis, was isolated from the cecum, with the inhibition zone diameter of 10.26 mm. Three strains of bacillus were isolated from the cecum, including Bacillus subtilis, B. cereus and B. licheniformis, and their inhibition zone diameters were 9.25, 8.46 and 8.37 mm, respectively. Daily drinking 2 billion units of viable bacteria was the safe dosage for chicks. [Conclusion] Eight strains of probiotics had certain inhibitory effect on Escherichia coli O;, and had no toxic side effects to chicks. Lactobacillus had strong antibacterial effect on E. coli O;, while the antibacterial effect of bacillus was relatively weak.展开更多
To meet the challenges of time searching for the new method for neuropsychopharmacology is still an ongoing process. In this experiment, we proposed and validated three neuropsychopharmacological testing methods, whic...To meet the challenges of time searching for the new method for neuropsychopharmacology is still an ongoing process. In this experiment, we proposed and validated three neuropsychopharmacological testing methods, which are Matching Capacity (MC), Dissimilarity Identification (DI) and Sense Making (SM) tests for the estimation of memory, attention and cognition respectively in healthy aged human participants. The purpose of this experiment was to generate more effective testing methods for the determination of memory, attention and cognition in human. To endorse proposed methods a randomized double blind placebo controlled clinical trial was conducted among healthy aged human participants between the period of December 2015 and February 2016. The experiment was conducted at Gazipur Sadar, Gazipur-1703, Dhaka, Bangladesh and the experiment center was the Department of Pharmacy, Southeast University, Dhaka-1213, Bangladesh. In this experiment, 60 healthy male participants between the age of 42 to 50 years were selected and divided into 4 groups with 15 participants in each by simple randomization process. Ginkgo biloba standardized extract’s capsule (Giloba?) and Bacopa monnieri standardized extract’s syrup (Monera?) were used as standard. Psyllium seed husk (i.e., seed of the Plantago ovata) was incorporated in the hard gelatin capsule shell (size 0) to prepare capsule and used as a placebo control of the capsule (PCC). Excipients of oral liquid preparation of vitamin were used to prepare syrup and used as a placebo control of the syrup (PCS). The treatment procedure for group 1 was Ginkgo biloba standardized extract’s capsule (120 mg/capsule), 3 times daily for 21 days;group 2 was treated with Bacopa monnieri standardized extract’s syrup (1.21 g/5 ml), 2 teaspoonfuls, 3 times daily for 21 days. Psyllium seed husk’s capsule and excipients of oral liquid vitamin’s syrup were used as placebo control (PC) for group 3 and group 4 and administered in the similar manner of group 1 and group 2, respectively. Administration of Ginkgo biloba (GB) and Bacopa monnieri (BM) standardized extracts for successive days significantly increased the memory, attention and cognition of the participants with respect to PC groups. In the MC test, treatment with GB extract markedly (P < 0.05) increased the memory of the participants on 21st day with respect to PCC group. On the other hand administration of BM extract remarkably (P < 0.01) increased the memory of the participants on 14th day in comparison with PCS group. For DI test, administration of GB extract noticeably (P < 0.01, P < 0.05) increased the attention of the participants on 14th and 21st day as compared to that of PCC group. Conversely BM extract significantly (P < 0.05, P < 0.01) increased the attention of the participants on 7th, 14th and 21st day with regard to PCS group. In the SM test, administration of GB extract noticeably (P < 0.05) increased the cognition of the participants on 7th and 21st day in comparison with PCC group. BM extract administration considerably (P < 0.01) increased cognition of the participants on 14th and 21st day related to the PCS groups. The experiment demonstrates that MC, DI and SM tests clearly exposed the memory, attention and cognition enhancing activity of the GB and BM standardized extracts in healthful aged human participants respectively. Therefore, the proposed method can be used for the fortitude of memory, attention and cognition in human and will generate a landmark in the sphere of neuroscience.展开更多
In May 2016,an epizootic occured among cultured tongue soles caused mass deaths in a fish farm in Qinhuangdao,China.In order to find out the etiological agent,a bacterial strain was isolated from ascites and other tis...In May 2016,an epizootic occured among cultured tongue soles caused mass deaths in a fish farm in Qinhuangdao,China.In order to find out the etiological agent,a bacterial strain was isolated from ascites and other tissues of sick tongue sole aseptically collected.The isolate was identified as Photobacterium damselae subsp.damsela(PDD) by isolation culture,Gram staining,physiological identification,morohological observation,biochemical identification and 16S rDNA sequence analysis.The results showed that the isolate shared 99.6% homology with the reference strain in GenBank.The animal regression test displayed that the isolate had very strong pathogenicity to tongue sole.The LD(50) was 3.1 × 10~4 CFU/mL,and it showed pathogenicity to mammals.The antimicrobial susceptibility test showed the isolate was highly sensitive to nrofloxacin,Norfloxacin,Ciprofloxacin,Mequindox;moderately sensitive to Cefradine,Doxycycline;and insensitive to Gentamicin,Ceftriaxone,Tilmicosin,etc..展开更多
Low-tempemture stress is a major abiotic stress influencing plant growth, economic yield and quality worldwide. Precise and reliable identification and test of plant cold resistance is a foundation for exploring low-t...Low-tempemture stress is a major abiotic stress influencing plant growth, economic yield and quality worldwide. Precise and reliable identification and test of plant cold resistance is a foundation for exploring low-temperature damages, cold resistance mechanism of plants, cultivating and innovating quality cold-re- sistant germplasm resources, which is rather important for woody plants because their perennial and large-sized characteristics. Generally, most researches on plant cold-resistant physiology focused on identification and utilization of cold resistance worldwide, and a few on test methods of cold resistance, but cold resistance mechanism has been less reported. Therefore, researches on methods of identifying and testing plant resistance have achieved considerable progress, accumulated much experience and formed characteristics gradually in terms of methodology. Current methods of identifying plant cold resistance include open field/outdoor culti- vation evaluation, cold and frost damage investigation, simulated cold weather, and mathematical model forecast. And the methods of testing plant cold resistance include growth condition test, frozen index investigation, electrolyte leakage, bioelectrical impedance mapping and so on. Synthesizing the methods of identifying and testing plant cold resistance should be a key matter in the present and future researches and application of plant cold resistance physiology, improvement and in- novation of the identification and test will be an important direction of the future researches. Identification and test of plant cold resistance based on genomies, meta- bonomics and proteomics should be the new trend of the researches on physiology and ecology of plant cold resistance.展开更多
In this paper our studies about the sequential testing program for predicting and identificating carcinogens, sequential discriminant method and cost- effectiveness analysis are summarized. The analysis of our databas...In this paper our studies about the sequential testing program for predicting and identificating carcinogens, sequential discriminant method and cost- effectiveness analysis are summarized. The analysis of our database of carcinogeniclty and genotoxicity of chemicals demonstrates the uncertainty . of short- term tests ( STTs ) to predict carcinogens and the results of most routine STTs are statistically dependent. We recommend the sequential testing program combining STTs and carclnogenicity assay, the optimal STT batteries, the rules of the sequential discrimination and the preferal choices of STTs tor specific chemical class. For illustrative pmposes the carclnogenicity prediction of several sample chamicals is presented. The results of cost-effectiveness analysis suggest that this program has vast social-economic effectiveness.展开更多
This paper aims to introduce the claim that hospitality students and hospitality employees drink more alcohol than other students and employee groups and to explore and explain this alcohol consumption disparity using...This paper aims to introduce the claim that hospitality students and hospitality employees drink more alcohol than other students and employee groups and to explore and explain this alcohol consumption disparity using the sense of coherence (SOC) construct. Using a web-based questionnaire, college students were recruited, surveyed, and classified into hospitality and non-hospitality majors. Self-reported alcohol consumption, SOC, and a variety of demographic variables were measured. A total of 930 students participated of which 59.4% were female and 28% were hospitality majors. About 47% of hospitality students, 33% of other majors, 43% of women, and 38% of men were classified as at-risk consumers of alcohol. The overall SOC score was about 139 with a range of 69-191. None of the sub-populations differed significantly in SOC. While SOC does not predict major or occupational choice, SOC is a predictor of risky alcohol consumption.展开更多
Augmented randomized complete block test was conducted to evaluate the heterosis of 80 hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S,and the combining a-bility of 40 testcrossing lines.T...Augmented randomized complete block test was conducted to evaluate the heterosis of 80 hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S,and the combining a-bility of 40 testcrossing lines.The results of identification test showed that among 47 combinations yielding over the control Xiangyou 15,17 ones with 402S and 3 ones with Xiangyou 91S overyielded more than 20%,reaching the significant level of 1 %;and among 51 combinations yielding over their corresponding higher yield parents,18 ones with 402S and 9 ones with Xiangyou 91S overyielded at 5% or 1% significant level.The test for the GCA effect of all parents indicated that 402S possessed a stronger combining ability than Xiangyou 91S on yield,ailiquae of main inflorescence,total siliquae per plant,seed yield of single plant and 1000 seed weight.10 testcrossing lines with high GCA were picked out for next testcrosses.Among 8 agronomic traits,total siliquae per plant and seed yield of single plant were regarded as the key selecting indexes according to the correlation analysis between yield and the agronomic traits on heterosis and on the GCA effect of all parents.展开更多
The aim of this study is to contribute to the mastery of the physical characteristics of lateritic soils in order to improve their use for the manufacture of Compressed Stabilized Earth Bricks (CSEB) in the province o...The aim of this study is to contribute to the mastery of the physical characteristics of lateritic soils in order to improve their use for the manufacture of Compressed Stabilized Earth Bricks (CSEB) in the province of North Kivu in the Democratic Republic of Congo (DRC). The study of the physical characteristics of lateritic soils was carried out. Samples were subjected to experimental identification tests on the physical characteristics (water content, density characteristics, particle size distribution and consistency). The results of the laboratory analysis of soil samples show that the water content varies between 5.4% and 36.99%. The density of the solid grains has an arithmetic mean of 2.5 g/cm</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">. The apparent density varies from 0.83 to 1.35 g/cm</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">. As for the dry density, it is in the range of 0.61 to 1.25 g/cm</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">. These relatively low densities indicate that the material studied ha</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> a significant degree of deformability. From the particle size analysis, it appears that the material studied contain</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> an important fraction of fine particles. According to the consistency study, the soils studied are plastic clay as Ap class according to the Central Laboratory for Roads and Bridges (CLRB) geotechnical classification system. The particle size curves of the studied samples are within the preferential range of good soils for the manufacture of CSEB. The points representing the studied samples are within the preferential plasticity range of good soils for the manufacture of CSEB. From the above parameters, it appears that the studied material is well adapted for the manufacture of the Compressed Stabilized Earth Bricks</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.展开更多
This paper eonsiders an ARIMA (p, d, q) medel. A method for estimating the order d and testingthe hypothesis: d=d_0 is given. The asymptotic properties of the estimator have been discussed.
Background: Smell and taste loss are highly prevalent symptoms in coronavirus disease 2019 (COVID-19), although few studies have employed objective measures to quantify these symptoms, especially dysgeusia. Reports of...Background: Smell and taste loss are highly prevalent symptoms in coronavirus disease 2019 (COVID-19), although few studies have employed objective measures to quantify these symptoms, especially dysgeusia. Reports of unrecognized anosmia in COVID-19 patients suggests that self-reported measures are insufficient for capturing patients with chemosensory dysfunction.Objectives: The purpose of this study was to quantify the impact of recent COVID-19 infection on chemosensory function and demonstrate the use of at-home objective smell and taste testing in an at-risk population of healthcare workers.Methods: Two hundred and fifty healthcare workers were screened for possible loss of smell and taste using online surveys. Self-administered smell and taste tests were mailed to respondents meeting criteria for elevated risk of infection, and one-month follow-up surveys were completed.Results: Among subjects with prior SARS-CoV-2 infection, 73% reported symptoms of olfactory and/or gustatory dysfunction. Self-reported smell and taste loss were both strong predictors of COVID-19 positivity. Subjects with evidence of recent SARS-CoV-2 infection (<45 days) had significantly lower olfactory scores but equivalent gustatory scores compared to other subjects. There was a time-dependent increase in smell scores but not in taste scores among subjects with prior infection and chemosensory symptoms. The overall infection rate was 4.4%, with 2.5% reported by PCR swab.Conclusion: Healthcare workers with recent SARS-CoV-2 infection had reduced olfaction and normal gustation on self-administered objective testing compared to those without infection. Rates of infection and chemosensory symptoms in our cohort of healthcare workers reflect those of the general public.展开更多
文摘Elements can be classified into metals,nonmetals,or metalloids based on their chemical and physical properties.Precious metals are rare and expensive.There are ten known precious metals,three of which are of interest to investors,silver,gold,and platinum.The goal is to find physical methods to identify the presence of precious metals,silver,and gold in the metal components of the computer motherboard,and to confirm its presence by chemical methods for its use and its selling to the jewelry industry after it is physically separated from the computer motherboards.Physical and chemical tests were identified.Physical tests include inscription test,magnet test and specific gravity test for both silver and gold metal pieces and chemical tests include bleach test,nitric acid test,test karat solution kit,and jewelry test kits.
文摘[Objective] The paper was to isolate and identify probiotics in the intestine of laying hens. [Method] The intestinal probiotics in laying hens at peak period were isolated using conventional separation methods; the physical and chemical properties of target strains and in vitro antibacterial effects were measured. Moreover, the safety test of chicks was conducted. [Result] Four strains of lactobacillus were isolated from the jejunum of laying hens, including Lactobacillus plantarum, Bacillus acidophilus, L. delbrueckii subsp. Delbrueckii and L. delbrueckii subsp. Lactis, and their inhibition zone diameters were 18.30, 16.07, 11.45, 17.26 mm, respectively. One strain of Lactobacillus, L. brevis, was isolated from the cecum, with the inhibition zone diameter of 10.26 mm. Three strains of bacillus were isolated from the cecum, including Bacillus subtilis, B. cereus and B. licheniformis, and their inhibition zone diameters were 9.25, 8.46 and 8.37 mm, respectively. Daily drinking 2 billion units of viable bacteria was the safe dosage for chicks. [Conclusion] Eight strains of probiotics had certain inhibitory effect on Escherichia coli O;, and had no toxic side effects to chicks. Lactobacillus had strong antibacterial effect on E. coli O;, while the antibacterial effect of bacillus was relatively weak.
文摘To meet the challenges of time searching for the new method for neuropsychopharmacology is still an ongoing process. In this experiment, we proposed and validated three neuropsychopharmacological testing methods, which are Matching Capacity (MC), Dissimilarity Identification (DI) and Sense Making (SM) tests for the estimation of memory, attention and cognition respectively in healthy aged human participants. The purpose of this experiment was to generate more effective testing methods for the determination of memory, attention and cognition in human. To endorse proposed methods a randomized double blind placebo controlled clinical trial was conducted among healthy aged human participants between the period of December 2015 and February 2016. The experiment was conducted at Gazipur Sadar, Gazipur-1703, Dhaka, Bangladesh and the experiment center was the Department of Pharmacy, Southeast University, Dhaka-1213, Bangladesh. In this experiment, 60 healthy male participants between the age of 42 to 50 years were selected and divided into 4 groups with 15 participants in each by simple randomization process. Ginkgo biloba standardized extract’s capsule (Giloba?) and Bacopa monnieri standardized extract’s syrup (Monera?) were used as standard. Psyllium seed husk (i.e., seed of the Plantago ovata) was incorporated in the hard gelatin capsule shell (size 0) to prepare capsule and used as a placebo control of the capsule (PCC). Excipients of oral liquid preparation of vitamin were used to prepare syrup and used as a placebo control of the syrup (PCS). The treatment procedure for group 1 was Ginkgo biloba standardized extract’s capsule (120 mg/capsule), 3 times daily for 21 days;group 2 was treated with Bacopa monnieri standardized extract’s syrup (1.21 g/5 ml), 2 teaspoonfuls, 3 times daily for 21 days. Psyllium seed husk’s capsule and excipients of oral liquid vitamin’s syrup were used as placebo control (PC) for group 3 and group 4 and administered in the similar manner of group 1 and group 2, respectively. Administration of Ginkgo biloba (GB) and Bacopa monnieri (BM) standardized extracts for successive days significantly increased the memory, attention and cognition of the participants with respect to PC groups. In the MC test, treatment with GB extract markedly (P < 0.05) increased the memory of the participants on 21st day with respect to PCC group. On the other hand administration of BM extract remarkably (P < 0.01) increased the memory of the participants on 14th day in comparison with PCS group. For DI test, administration of GB extract noticeably (P < 0.01, P < 0.05) increased the attention of the participants on 14th and 21st day as compared to that of PCC group. Conversely BM extract significantly (P < 0.05, P < 0.01) increased the attention of the participants on 7th, 14th and 21st day with regard to PCS group. In the SM test, administration of GB extract noticeably (P < 0.05) increased the cognition of the participants on 7th and 21st day in comparison with PCC group. BM extract administration considerably (P < 0.01) increased cognition of the participants on 14th and 21st day related to the PCS groups. The experiment demonstrates that MC, DI and SM tests clearly exposed the memory, attention and cognition enhancing activity of the GB and BM standardized extracts in healthful aged human participants respectively. Therefore, the proposed method can be used for the fortitude of memory, attention and cognition in human and will generate a landmark in the sphere of neuroscience.
基金Supported by Incentive Subsidy Program of Hebei Department of Science and Technology(15926620H)Key Technology R&D Program of Qinhuangdao Science and Technology Bureau(201401A067)+1 种基金Prevention and Control of Major Bacterial Diseases in Industrial Farming Fishes(201602A341)Sereening and Preliminary Application of Protective Antigen of Two Important Marine Pathogens(2018HY007)
文摘In May 2016,an epizootic occured among cultured tongue soles caused mass deaths in a fish farm in Qinhuangdao,China.In order to find out the etiological agent,a bacterial strain was isolated from ascites and other tissues of sick tongue sole aseptically collected.The isolate was identified as Photobacterium damselae subsp.damsela(PDD) by isolation culture,Gram staining,physiological identification,morohological observation,biochemical identification and 16S rDNA sequence analysis.The results showed that the isolate shared 99.6% homology with the reference strain in GenBank.The animal regression test displayed that the isolate had very strong pathogenicity to tongue sole.The LD(50) was 3.1 × 10~4 CFU/mL,and it showed pathogenicity to mammals.The antimicrobial susceptibility test showed the isolate was highly sensitive to nrofloxacin,Norfloxacin,Ciprofloxacin,Mequindox;moderately sensitive to Cefradine,Doxycycline;and insensitive to Gentamicin,Ceftriaxone,Tilmicosin,etc..
基金Supported by the National Natural Science Fundation of China(No.31270674)
文摘Low-tempemture stress is a major abiotic stress influencing plant growth, economic yield and quality worldwide. Precise and reliable identification and test of plant cold resistance is a foundation for exploring low-temperature damages, cold resistance mechanism of plants, cultivating and innovating quality cold-re- sistant germplasm resources, which is rather important for woody plants because their perennial and large-sized characteristics. Generally, most researches on plant cold-resistant physiology focused on identification and utilization of cold resistance worldwide, and a few on test methods of cold resistance, but cold resistance mechanism has been less reported. Therefore, researches on methods of identifying and testing plant resistance have achieved considerable progress, accumulated much experience and formed characteristics gradually in terms of methodology. Current methods of identifying plant cold resistance include open field/outdoor culti- vation evaluation, cold and frost damage investigation, simulated cold weather, and mathematical model forecast. And the methods of testing plant cold resistance include growth condition test, frozen index investigation, electrolyte leakage, bioelectrical impedance mapping and so on. Synthesizing the methods of identifying and testing plant cold resistance should be a key matter in the present and future researches and application of plant cold resistance physiology, improvement and in- novation of the identification and test will be an important direction of the future researches. Identification and test of plant cold resistance based on genomies, meta- bonomics and proteomics should be the new trend of the researches on physiology and ecology of plant cold resistance.
文摘In this paper our studies about the sequential testing program for predicting and identificating carcinogens, sequential discriminant method and cost- effectiveness analysis are summarized. The analysis of our database of carcinogeniclty and genotoxicity of chemicals demonstrates the uncertainty . of short- term tests ( STTs ) to predict carcinogens and the results of most routine STTs are statistically dependent. We recommend the sequential testing program combining STTs and carclnogenicity assay, the optimal STT batteries, the rules of the sequential discrimination and the preferal choices of STTs tor specific chemical class. For illustrative pmposes the carclnogenicity prediction of several sample chamicals is presented. The results of cost-effectiveness analysis suggest that this program has vast social-economic effectiveness.
文摘This paper aims to introduce the claim that hospitality students and hospitality employees drink more alcohol than other students and employee groups and to explore and explain this alcohol consumption disparity using the sense of coherence (SOC) construct. Using a web-based questionnaire, college students were recruited, surveyed, and classified into hospitality and non-hospitality majors. Self-reported alcohol consumption, SOC, and a variety of demographic variables were measured. A total of 930 students participated of which 59.4% were female and 28% were hospitality majors. About 47% of hospitality students, 33% of other majors, 43% of women, and 38% of men were classified as at-risk consumers of alcohol. The overall SOC score was about 139 with a range of 69-191. None of the sub-populations differed significantly in SOC. While SOC does not predict major or occupational choice, SOC is a predictor of risky alcohol consumption.
文摘Augmented randomized complete block test was conducted to evaluate the heterosis of 80 hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S,and the combining a-bility of 40 testcrossing lines.The results of identification test showed that among 47 combinations yielding over the control Xiangyou 15,17 ones with 402S and 3 ones with Xiangyou 91S overyielded more than 20%,reaching the significant level of 1 %;and among 51 combinations yielding over their corresponding higher yield parents,18 ones with 402S and 9 ones with Xiangyou 91S overyielded at 5% or 1% significant level.The test for the GCA effect of all parents indicated that 402S possessed a stronger combining ability than Xiangyou 91S on yield,ailiquae of main inflorescence,total siliquae per plant,seed yield of single plant and 1000 seed weight.10 testcrossing lines with high GCA were picked out for next testcrosses.Among 8 agronomic traits,total siliquae per plant and seed yield of single plant were regarded as the key selecting indexes according to the correlation analysis between yield and the agronomic traits on heterosis and on the GCA effect of all parents.
文摘The aim of this study is to contribute to the mastery of the physical characteristics of lateritic soils in order to improve their use for the manufacture of Compressed Stabilized Earth Bricks (CSEB) in the province of North Kivu in the Democratic Republic of Congo (DRC). The study of the physical characteristics of lateritic soils was carried out. Samples were subjected to experimental identification tests on the physical characteristics (water content, density characteristics, particle size distribution and consistency). The results of the laboratory analysis of soil samples show that the water content varies between 5.4% and 36.99%. The density of the solid grains has an arithmetic mean of 2.5 g/cm</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">. The apparent density varies from 0.83 to 1.35 g/cm</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">. As for the dry density, it is in the range of 0.61 to 1.25 g/cm</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">. These relatively low densities indicate that the material studied ha</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> a significant degree of deformability. From the particle size analysis, it appears that the material studied contain</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> an important fraction of fine particles. According to the consistency study, the soils studied are plastic clay as Ap class according to the Central Laboratory for Roads and Bridges (CLRB) geotechnical classification system. The particle size curves of the studied samples are within the preferential range of good soils for the manufacture of CSEB. The points representing the studied samples are within the preferential plasticity range of good soils for the manufacture of CSEB. From the above parameters, it appears that the studied material is well adapted for the manufacture of the Compressed Stabilized Earth Bricks</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.
文摘This paper eonsiders an ARIMA (p, d, q) medel. A method for estimating the order d and testingthe hypothesis: d=d_0 is given. The asymptotic properties of the estimator have been discussed.
文摘Background: Smell and taste loss are highly prevalent symptoms in coronavirus disease 2019 (COVID-19), although few studies have employed objective measures to quantify these symptoms, especially dysgeusia. Reports of unrecognized anosmia in COVID-19 patients suggests that self-reported measures are insufficient for capturing patients with chemosensory dysfunction.Objectives: The purpose of this study was to quantify the impact of recent COVID-19 infection on chemosensory function and demonstrate the use of at-home objective smell and taste testing in an at-risk population of healthcare workers.Methods: Two hundred and fifty healthcare workers were screened for possible loss of smell and taste using online surveys. Self-administered smell and taste tests were mailed to respondents meeting criteria for elevated risk of infection, and one-month follow-up surveys were completed.Results: Among subjects with prior SARS-CoV-2 infection, 73% reported symptoms of olfactory and/or gustatory dysfunction. Self-reported smell and taste loss were both strong predictors of COVID-19 positivity. Subjects with evidence of recent SARS-CoV-2 infection (<45 days) had significantly lower olfactory scores but equivalent gustatory scores compared to other subjects. There was a time-dependent increase in smell scores but not in taste scores among subjects with prior infection and chemosensory symptoms. The overall infection rate was 4.4%, with 2.5% reported by PCR swab.Conclusion: Healthcare workers with recent SARS-CoV-2 infection had reduced olfaction and normal gustation on self-administered objective testing compared to those without infection. Rates of infection and chemosensory symptoms in our cohort of healthcare workers reflect those of the general public.