Gravel roads require a continuous maintenance and regraveling cycle to maintain the required surface quality and the desired level of service. Surface material loss is a way of deterioration of unpaved road by which the reduction of thickness of gravel wearing course by various factors through time. To keep it in mind the responsible body or roads authority should predict the gravel loss in order to account for maintenance or rehabilitation requirement after a given period. This should be based up on regraveling frequency from predicted gravel loss during construction or after the first maintenance. Here main factors included for study are ADT, mean monthly precipitation of locations, plasticity index of surfacing material and absolute value of gradient of the road as independent variables and gravel loss as dependent variable. The road segments selected are Sodo-Gesuba road(29km), Humbo-Menuka(13km) and Sodo zuriya-Gulgula(11km) road segments. The monthly rainfall data from SNNPR meteorological agency was used as secondary data and all other data was collected from field survey. The data collected for modeling are based up on the basic scientific methods and collected data was analyzed by statistical software IBM SPSS statistics 20 and Microsoft Excel 2019 in order to develop a model. The developed model indicates that gradient of the road is critical factor hence its unit change accelerates loss of gravel by 4.7316, a unit change in ADT lead to 0.1225 change in gravel loss, a unit change in mean monthly precipitation of locations lead to 0.1460 change in gravel loss and a unit change in plasticity index of surfacing material lead to -1.3473 change in gravel loss. From regression output R2 also called coefficient of determination which is the proportion of variance in the dependent variable that can be explained by the independent variables, and is equal to 0.985 for model which means gravel loss contributing factors here in this study explain 98.5% of variability of gravel loss and that statistical package strongly reinforced the correlation. Keywords: Gravel loss, Regraveling, gravel resurfacing, absolute gradient, multiple linear regression and modeling DOI : 10.7176/CMR/11-6-02 Publication date : August 31st 2019
{"title":"Evaluating Surface Material Loss for Gravel Road","authors":"Mengistu Mena Kuleno","doi":"10.7176/cmr/11-6-02","DOIUrl":"https://doi.org/10.7176/cmr/11-6-02","url":null,"abstract":"Gravel roads require a continuous maintenance and regraveling cycle to maintain the required surface quality and the desired level of service. Surface material loss is a way of deterioration of unpaved road by which the reduction of thickness of gravel wearing course by various factors through time. To keep it in mind the responsible body or roads authority should predict the gravel loss in order to account for maintenance or rehabilitation requirement after a given period. This should be based up on regraveling frequency from predicted gravel loss during construction or after the first maintenance. Here main factors included for study are ADT, mean monthly precipitation of locations, plasticity index of surfacing material and absolute value of gradient of the road as independent variables and gravel loss as dependent variable. The road segments selected are Sodo-Gesuba road(29km), Humbo-Menuka(13km) and Sodo zuriya-Gulgula(11km) road segments. The monthly rainfall data from SNNPR meteorological agency was used as secondary data and all other data was collected from field survey. The data collected for modeling are based up on the basic scientific methods and collected data was analyzed by statistical software IBM SPSS statistics 20 and Microsoft Excel 2019 in order to develop a model. The developed model indicates that gradient of the road is critical factor hence its unit change accelerates loss of gravel by 4.7316, a unit change in ADT lead to 0.1225 change in gravel loss, a unit change in mean monthly precipitation of locations lead to 0.1460 change in gravel loss and a unit change in plasticity index of surfacing material lead to -1.3473 change in gravel loss. From regression output R2 also called coefficient of determination which is the proportion of variance in the dependent variable that can be explained by the independent variables, and is equal to 0.985 for model which means gravel loss contributing factors here in this study explain 98.5% of variability of gravel loss and that statistical package strongly reinforced the correlation. Keywords: Gravel loss, Regraveling, gravel resurfacing, absolute gradient, multiple linear regression and modeling DOI : 10.7176/CMR/11-6-02 Publication date : August 31st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86913489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rue ( Ruta chalepensis ) commonly known as rue, is traditionally used in Ethiopia for the treatment of a variety of diseases. Therefore this study conducted to investigate phytochemical constituents, antibacterial and antioxidant activity of the leave extracts of Ruta chalepensis . The phytochemical screening tests were conducted as per the standard procedure to identify the classes of compounds present in the leave extract of Ruta chalepensis . In vitro antibacterial activities of crude extracts were evaluated via disc diffusion method while antioxidant activities of extracts were determined by DPPH assay, the phosphomolybdenum method and total flavonoid contents were determined as per of the standard procedures. Phytochemical screening of leave extracts of Ruta chalepensis revealed the presence of secondary metabolites. The methanol extract had the greatest DPPH scavenging (93.851±0.148%) and total antioxidant (1.63 ± 0.19 mg AAE/g of dried extract) activities. Ethyl acetate extract showed the growth suppression of Bacillus cereus and Escherichia coli and methanol extract showed growth suppression of Bacillus cereus and Staphylococcus aureus with minimum inhibition concentration 50mg/mL. The antibacterial activities of the extracts were compared with a commercially available antibiotic (chloramphenicol) and showed moderate antibacterial activities, with inhibition zones ranging between 18–28 mm. Therefore the solvent extracts of Ruta chalepensis revealed the presence of important secondary metabolites, antibacterial and antioxidant activities. Keywords: Antimicrobial activity, antioxidant activity, phytochemical profile, Ruta chalepensis DOI : 10.7176/CMR/11-6-01 Publication date : August 31st 2019
{"title":"Phytochemical Analysis, Antibacterial and Antioxidant Activity of the Leave Extracts of Ruta Chalepensis","authors":"Ketema Alemayehu","doi":"10.7176/cmr/11-6-01","DOIUrl":"https://doi.org/10.7176/cmr/11-6-01","url":null,"abstract":"Rue ( Ruta chalepensis ) commonly known as rue, is traditionally used in Ethiopia for the treatment of a variety of diseases. Therefore this study conducted to investigate phytochemical constituents, antibacterial and antioxidant activity of the leave extracts of Ruta chalepensis . The phytochemical screening tests were conducted as per the standard procedure to identify the classes of compounds present in the leave extract of Ruta chalepensis . In vitro antibacterial activities of crude extracts were evaluated via disc diffusion method while antioxidant activities of extracts were determined by DPPH assay, the phosphomolybdenum method and total flavonoid contents were determined as per of the standard procedures. Phytochemical screening of leave extracts of Ruta chalepensis revealed the presence of secondary metabolites. The methanol extract had the greatest DPPH scavenging (93.851±0.148%) and total antioxidant (1.63 ± 0.19 mg AAE/g of dried extract) activities. Ethyl acetate extract showed the growth suppression of Bacillus cereus and Escherichia coli and methanol extract showed growth suppression of Bacillus cereus and Staphylococcus aureus with minimum inhibition concentration 50mg/mL. The antibacterial activities of the extracts were compared with a commercially available antibiotic (chloramphenicol) and showed moderate antibacterial activities, with inhibition zones ranging between 18–28 mm. Therefore the solvent extracts of Ruta chalepensis revealed the presence of important secondary metabolites, antibacterial and antioxidant activities. Keywords: Antimicrobial activity, antioxidant activity, phytochemical profile, Ruta chalepensis DOI : 10.7176/CMR/11-6-01 Publication date : August 31st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76245439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ajuga integrifolia belongs to the family of Lamiaceae. The leaves were collected and extract prepared from petroleum ether, chloroform, ethyl acetate and methanol. Different types and effective compounds were qualitatively conformed using standard methods. These metabolites were flavonoids, phenol, alkaloids, flavonoids, glycosides, saponins, tannins, phenol, lignin etc. These metabolites show their high effectivity by which they belong to medicinal plant category. Keywords: Ajuga integrifolia , secondary metabolites, Flavonoids , Alkaloids, Tannins, phenols. DOI : 10.7176/CMR/11-5-02 Publication date :May 31 st 2019
{"title":"Phytochemical Screening of Secondary Metabolites of Extracts of the Plant Ajuga Integrifolia Leaves","authors":"Birhanu Ayalew Tebeje","doi":"10.7176/cmr/11-5-02","DOIUrl":"https://doi.org/10.7176/cmr/11-5-02","url":null,"abstract":"Ajuga integrifolia belongs to the family of Lamiaceae. The leaves were collected and extract prepared from petroleum ether, chloroform, ethyl acetate and methanol. Different types and effective compounds were qualitatively conformed using standard methods. These metabolites were flavonoids, phenol, alkaloids, flavonoids, glycosides, saponins, tannins, phenol, lignin etc. These metabolites show their high effectivity by which they belong to medicinal plant category. Keywords: Ajuga integrifolia , secondary metabolites, Flavonoids , Alkaloids, Tannins, phenols. DOI : 10.7176/CMR/11-5-02 Publication date :May 31 st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75687747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Ivanova, J. Seeger, J. M. Serra, C. Solís, W. Meulenberg, Werner, Fischer, S. Roitsch, H. Buchkremer
The aim of the present work is to evaluate the influence of La6W2O15 secondary phase on the properties and integrity of La6-xWO12-δ–based membranes. Structural, microstructural and thermo–chemical study was carried out evidencing significant crystallographic and thermal expansion anisotropy: the reason for poor thermo–mechanical stability of La6W2O15. Conductivity of La6W2O15 was one to two orders of magnitude lower compared to the phase pure La6-xWO12-δ in the range of 300 to 900 °C. The relaxation study showed that the hydration process was faster for the La6W2O15 compared to the LWO phase, due to the higher electronic contribution to the total conductivity. Short–term stability tests in H2 at 900 °C and in a mixture of CO2 and CH4 at 750 °C were conducted and material remained stable. Remarkable reactivity with NiO and YSZ at elevated temperatures was further evidenced compared to the relative inert behavior towards MgO and CGO.
{"title":"Influence of the La6W2O15 Phase on the Properties and Integrity of La6-xWO12-?–Based Membranes","authors":"M. Ivanova, J. Seeger, J. M. Serra, C. Solís, W. Meulenberg, Werner, Fischer, S. Roitsch, H. Buchkremer","doi":"10.7176/cmr/2012-2-1-5","DOIUrl":"https://doi.org/10.7176/cmr/2012-2-1-5","url":null,"abstract":"The aim of the present work is to evaluate the influence of La6W2O15 secondary phase on the properties and integrity of La6-xWO12-δ–based membranes. Structural, microstructural and thermo–chemical study was carried out evidencing significant crystallographic and thermal expansion anisotropy: the reason for poor thermo–mechanical stability of La6W2O15. Conductivity of La6W2O15 was one to two orders of magnitude lower compared to the phase pure La6-xWO12-δ in the range of 300 to 900 °C. The relaxation study showed that the hydration process was faster for the La6W2O15 compared to the LWO phase, due to the higher electronic contribution to the total conductivity. Short–term stability tests in H2 at 900 °C and in a mixture of CO2 and CH4 at 750 °C were conducted and material remained stable. Remarkable reactivity with NiO and YSZ at elevated temperatures was further evidenced compared to the relative inert behavior towards MgO and CGO.","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78472069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chalcones are synthesized by Claisen-Schmidt condensation, which involves cross-aldol condensation of appropriate aldehydes and ketones by base catalyzed reaction, the new chalcone derivatives synthesized by the reaction aldehyde with their compounds. By microwave assisted synthesis, a considerable increase in the reaction rate has been observed and that too, with better yields. M.P., TLC, CHN, FTIR, NMR and MS spectroscopy has characterized all the synthesized compounds. The biological screening data of the synthesized compounds were also studied. Keywords : microwave, chalcone, antibacterial. DOI : 10.7176/CMR/11-3-05 Publication date :March 31 st 2019
{"title":"Microwave Assisted Synthesis, Characterization and Biological Study of Some Chalcone Compounds Derived from Phenyl Isothiocyanate","authors":"S. K. Al-Mosawi, H. Al-hazam, A. F. Abbas","doi":"10.7176/cmr/11-3-05","DOIUrl":"https://doi.org/10.7176/cmr/11-3-05","url":null,"abstract":"Chalcones are synthesized by Claisen-Schmidt condensation, which involves cross-aldol condensation of appropriate aldehydes and ketones by base catalyzed reaction, the new chalcone derivatives synthesized by the reaction aldehyde with their compounds. By microwave assisted synthesis, a considerable increase in the reaction rate has been observed and that too, with better yields. M.P., TLC, CHN, FTIR, NMR and MS spectroscopy has characterized all the synthesized compounds. The biological screening data of the synthesized compounds were also studied. Keywords : microwave, chalcone, antibacterial. DOI : 10.7176/CMR/11-3-05 Publication date :March 31 st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"50 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90066143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The study examined the effect of meta-cognitive strategy (KWL) and secondary school students’ academic achievement and retention in chemistry in Uyo metropolis in Akwa Ibom state, Nigeria. Two research questions were raised and two hypotheses formulated to guide the study. The design for the study was a pretest posttest quasi-experimental. Two out of fifteen public secondary schools in Uyo metropolis of Akwa Ibom state were randomly selected for the study. A sample of one hundred (100) SS11 students consisting of 47 boys and 57 girls from two intact classes were drawn from the selected schools. Two validated instruments tagged chemistry achievement test (CAT) and chemistry retention test (CRT) containing 25 items each were used to collect data. The reliability co-efficient of CAT and CRT were determined using test-retest method. The data obtained were analysed using Pearson Product Moment Correlation (PPMC) and the reliability coefficients of 0.81 for CAT and 0.77 for CRT were obtained respectively. Mean and standard deviation were used to answer research questions and analysis of covariance (ANCOVA) was used to test hypotheses at 0.05 level of significance. The findings showed a significant difference in achievement and retention scores of chemistry students taught alkanols using KWL and those taught with expository strategy. It is recommended that chemistry teachers use Know- What and Learn meta-cognitive strategy during instructional delivery to make teaching and learning more participatory, self monitoring and self evaluating so as deeper to understanding and retention of chemistry concepts. Keywords : Meta-cognitive strategy, Know- What and Learn, expository, chemistry Achievement, self monitoring, Retention DOI : 10.7176/CMR/11-3-04 Publication date :March 31 st 2019
{"title":"Meta-cognitive Strategy and Secondary School Students’ Achievement and Retention in Chemistry","authors":"Theresa M. Udofia, Uduak P. Edem","doi":"10.7176/cmr/11-3-04","DOIUrl":"https://doi.org/10.7176/cmr/11-3-04","url":null,"abstract":"The study examined the effect of meta-cognitive strategy (KWL) and secondary school students’ academic achievement and retention in chemistry in Uyo metropolis in Akwa Ibom state, Nigeria. Two research questions were raised and two hypotheses formulated to guide the study. The design for the study was a pretest posttest quasi-experimental. Two out of fifteen public secondary schools in Uyo metropolis of Akwa Ibom state were randomly selected for the study. A sample of one hundred (100) SS11 students consisting of 47 boys and 57 girls from two intact classes were drawn from the selected schools. Two validated instruments tagged chemistry achievement test (CAT) and chemistry retention test (CRT) containing 25 items each were used to collect data. The reliability co-efficient of CAT and CRT were determined using test-retest method. The data obtained were analysed using Pearson Product Moment Correlation (PPMC) and the reliability coefficients of 0.81 for CAT and 0.77 for CRT were obtained respectively. Mean and standard deviation were used to answer research questions and analysis of covariance (ANCOVA) was used to test hypotheses at 0.05 level of significance. The findings showed a significant difference in achievement and retention scores of chemistry students taught alkanols using KWL and those taught with expository strategy. It is recommended that chemistry teachers use Know- What and Learn meta-cognitive strategy during instructional delivery to make teaching and learning more participatory, self monitoring and self evaluating so as deeper to understanding and retention of chemistry concepts. Keywords : Meta-cognitive strategy, Know- What and Learn, expository, chemistry Achievement, self monitoring, Retention DOI : 10.7176/CMR/11-3-04 Publication date :March 31 st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86972538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pesticides usage in agricultural fields to control pests is extremely toxic to non-target organisms like fish and affects fish health through deterioration of metabolism, and sometimes leading to death. The present study was carried out to determine the level of organochlorine (OC) pesticide residues in, water and fish (Catfish and Tilapia) from Lake Geriyo, in Adamawa State, Nigeria, in order to find out the extent of pesticide contamination and accumulation in the lake. Soxhlet extraction process was used for the extraction of fish using a mixture of hexane and acetone, while water sample was extracted using dichloromethane liquid- liquid extraction method. The extracts were cleaned-up and analyzed using a gas chromatograph mass spectrometer (GC-MS). The result shows that organochlorine pesticides residues such as endrin, aldrin, dieldrin, heptachlor were detected in the water and the fish samples of the study area. Dieldrin was the predominant residue in all the fish samples analysed, at the concentration range of 0.36mg/kg to 0.57mg/kg and 0. 051mg/kg to 0.047mg/kg in Tilapia and catfish respectively, while Lindane was of higher concentration in water samples, (0.33mg/L) in point p1 upstream and 0.27mg/L in point p2 downstream. The lowest levels of OC pesticides were related to Endrin, Aldrin and Heptachlor in which Endrin and Heptachor were not found in water samples. The result of the investigation shows that matured fish contain higher concentration of the OC pesticide residues than the immature fish. Dieldrin and Lindane were found to be the predominant pesticide residues in all the analysed water and fish samples. Therefore the result indicates that Lake Gariyo is contaminated by pesticide from the nearby vegetable gardens which affects the water quality and non target organisms like fishes thereof. Keywords: Organochlorine, Pesticides, Lake Geriyo, Adamawa State, Fish and Water DOI : 10.7176/CMR/11-2-03
{"title":"Evaluation of Organochlorine Pesticide Residues in Fish and Water from Lake Geriyo in Yola North Local Government Area of Adamawa State, Nigeria","authors":"P. Alexander, Mohammed Minkailu, I. Y. Sudi","doi":"10.7176/cmr/11-2-03","DOIUrl":"https://doi.org/10.7176/cmr/11-2-03","url":null,"abstract":"Pesticides usage in agricultural fields to control pests is extremely toxic to non-target organisms like fish and affects fish health through deterioration of metabolism, and sometimes leading to death. The present study was carried out to determine the level of organochlorine (OC) pesticide residues in, water and fish (Catfish and Tilapia) from Lake Geriyo, in Adamawa State, Nigeria, in order to find out the extent of pesticide contamination and accumulation in the lake. Soxhlet extraction process was used for the extraction of fish using a mixture of hexane and acetone, while water sample was extracted using dichloromethane liquid- liquid extraction method. The extracts were cleaned-up and analyzed using a gas chromatograph mass spectrometer (GC-MS). The result shows that organochlorine pesticides residues such as endrin, aldrin, dieldrin, heptachlor were detected in the water and the fish samples of the study area. Dieldrin was the predominant residue in all the fish samples analysed, at the concentration range of 0.36mg/kg to 0.57mg/kg and 0. 051mg/kg to 0.047mg/kg in Tilapia and catfish respectively, while Lindane was of higher concentration in water samples, (0.33mg/L) in point p1 upstream and 0.27mg/L in point p2 downstream. The lowest levels of OC pesticides were related to Endrin, Aldrin and Heptachlor in which Endrin and Heptachor were not found in water samples. The result of the investigation shows that matured fish contain higher concentration of the OC pesticide residues than the immature fish. Dieldrin and Lindane were found to be the predominant pesticide residues in all the analysed water and fish samples. Therefore the result indicates that Lake Gariyo is contaminated by pesticide from the nearby vegetable gardens which affects the water quality and non target organisms like fishes thereof. Keywords: Organochlorine, Pesticides, Lake Geriyo, Adamawa State, Fish and Water DOI : 10.7176/CMR/11-2-03","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87807281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work the concentration of some selected pesticides such as aldrin, dialdrin, BHC, diazinon, DDT, 4,4-DDE and heptachlor were investigated in water and khat samples that were collected from five different sites. The pesticides were extracted using liquid-liquid and solid phase extraction technique and analyzed by GC-ECD. The recovery test, linearity cure and extraction efficiency were tested by using standard pesticide samples. The highest concentration of pesticide obtained in water samples is diazinon in WS 2 (0.0698mg/L), and the lowest concentration is heptachlor in WS 3 (0.0006mg/L). The highest and lowest concentrations of pesticides obtained in Khat samples are diazinon in KS 1 (0.0323mg/L) and KS 3 (0.0001mg/L) respectively. The concentration of diazinon and four isomers of BHC detected in each water sample are higher than the recommended limits set by WHO which shows contamination of the lake water. Diazinon and DDT levels in KS 1 (0.0323mg/L), KS 2 (0.0293mg/L) and KS1 (0.0134mg/L), KS 2 (0.0173mg/L) respectively are above the maximum residue level. Keywords: concentration, DDT, diazinon, extraction, heptachlor DOI : 10.7176/CMR/11-3-03 Publication date :March 31 st 2019
{"title":"Determination of Pesticide Residue in Water and Khat (Catha edulis) Leaves Using GC-ECD","authors":"Dagne Bayih Adamu","doi":"10.7176/cmr/11-3-03","DOIUrl":"https://doi.org/10.7176/cmr/11-3-03","url":null,"abstract":"In this work the concentration of some selected pesticides such as aldrin, dialdrin, BHC, diazinon, DDT, 4,4-DDE and heptachlor were investigated in water and khat samples that were collected from five different sites. The pesticides were extracted using liquid-liquid and solid phase extraction technique and analyzed by GC-ECD. The recovery test, linearity cure and extraction efficiency were tested by using standard pesticide samples. The highest concentration of pesticide obtained in water samples is diazinon in WS 2 (0.0698mg/L), and the lowest concentration is heptachlor in WS 3 (0.0006mg/L). The highest and lowest concentrations of pesticides obtained in Khat samples are diazinon in KS 1 (0.0323mg/L) and KS 3 (0.0001mg/L) respectively. The concentration of diazinon and four isomers of BHC detected in each water sample are higher than the recommended limits set by WHO which shows contamination of the lake water. Diazinon and DDT levels in KS 1 (0.0323mg/L), KS 2 (0.0293mg/L) and KS1 (0.0134mg/L), KS 2 (0.0173mg/L) respectively are above the maximum residue level. Keywords: concentration, DDT, diazinon, extraction, heptachlor DOI : 10.7176/CMR/11-3-03 Publication date :March 31 st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82144799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natural fiber-reinforced composites have attracted the attention of the research community mainly because they are turning out to be an alternative solution to the ever depleting petroleum sources and have additional advantages emanating from their low cost, low density, renewability, recyclability and biodegradability over glass fiber. In this regard, Enset plant is a main staple crop in southern and central Ethiopia where the pulp is fermented for food production but its strong fibers are now only used for local rope making or they are discarded. This paper presents the characteristics of Enset fiber under flexural loading conditions. So, a fiber reinforced composite specimen with different standard span length, fiber age, and fiber volume fraction has been considered. The experiment has been designed and analyzed using Optimal Experiment Design and Taguchi array platform on JMP and Minitab software package. After density of the fiber is measured by a Gas Pycnometery, different range of flexural loading and different loading condition (intermittent and one time) using Instron machine has been applied and the result has been analyzed and interpreted accordingly. This work, finally, reports the flexural properties of the fiber to be: Density: 1.4 g/cm 3 ; Flexural strength at maximum load: 121.6Mpa-215.0Mpa, Mean strength at maximum load: 162.4; Mean strength at maximum extension: 96.47MP; Modulus: 8.081Gpa-12.02Gpa, Mean modulus: 10.903MPa. Variation and standard deviation amid the results are minimal because of the bundle fiber sharing the load and reinforcing each other. Keywords: Fiber, Enset, Processing, flexural DOI : 10.7176/CMR/11-8-02 Publication date :October 31 st 2019
{"title":"Flexural Properties of Unidirectional Enset Fiber Reinforced Epoxy Composite for Automotive Interior Application","authors":"Fasil Tadesse","doi":"10.7176/cmr/11-8-02","DOIUrl":"https://doi.org/10.7176/cmr/11-8-02","url":null,"abstract":"Natural fiber-reinforced composites have attracted the attention of the research community mainly because they are turning out to be an alternative solution to the ever depleting petroleum sources and have additional advantages emanating from their low cost, low density, renewability, recyclability and biodegradability over glass fiber. In this regard, Enset plant is a main staple crop in southern and central Ethiopia where the pulp is fermented for food production but its strong fibers are now only used for local rope making or they are discarded. This paper presents the characteristics of Enset fiber under flexural loading conditions. So, a fiber reinforced composite specimen with different standard span length, fiber age, and fiber volume fraction has been considered. The experiment has been designed and analyzed using Optimal Experiment Design and Taguchi array platform on JMP and Minitab software package. After density of the fiber is measured by a Gas Pycnometery, different range of flexural loading and different loading condition (intermittent and one time) using Instron machine has been applied and the result has been analyzed and interpreted accordingly. This work, finally, reports the flexural properties of the fiber to be: Density: 1.4 g/cm 3 ; Flexural strength at maximum load: 121.6Mpa-215.0Mpa, Mean strength at maximum load: 162.4; Mean strength at maximum extension: 96.47MP; Modulus: 8.081Gpa-12.02Gpa, Mean modulus: 10.903MPa. Variation and standard deviation amid the results are minimal because of the bundle fiber sharing the load and reinforcing each other. Keywords: Fiber, Enset, Processing, flexural DOI : 10.7176/CMR/11-8-02 Publication date :October 31 st 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86394071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the effects of Jigsaw IV Cooperative Learning Strategy (J4CLS) on Students’ Academic Performance in Organic Chemistry in Zaria Education Zone. A pretest and posttest Quasi-experimental research design was used for the study which featured two groups (Experimental and Control groups). The experimental group was exposed to Jigsaw IV Cooperative Learning Strategy while the control group was taught using Conventional Method of Teaching (CMT). A Sample sizes of 234 students selected from two Senior Secondary Schools in Zaria Education zone was used as the study sample, drawn from a population of 11 schools with a total of 1154 students. The two schools selected, were pretested, to find their academic equivalence before the treatment. The instrument developed was Organic Chemistry Performance Test (OCPT) with a reliability coefficient of 0.88 was used for data collection. The data collected was analyzed using Mean scores, Standard deviation, Analysis of Covariate (ANCOVA) and t-test statistics at P≤ 0.05 level of significance. The findings indicated that, there is significant difference between the mean performance scores of science students taught Organic Chemistry concepts with Jigsaw IV Cooperative Learning Strategy and their counterparts taught with CMT in Zaria Education zone. However, students’ gender had no influence on their academic performance. Based on the findings, it was recommended among others that Chemistry teachers should incorporate into main streams of pedagogy in the teaching of chemistry at Senior Secondary Schools the use of Jigsaw IV Cooperative Learning Strategy to improve students’ cognitive and affective outcomes among others. Keywords: Jigsaw IV Cooperative Learning Strategy, Academic Performance, Organic Chemistry DOI : 10.7176/CMR/11-9-03 Publication date: November 30 th 2019
{"title":"Effects of Jigsaw IV Cooperative Learning Strategy on Students’ Academic Performance in Organic Chemistry in Zaria Education Zone, Kaduna State, Nigeria","authors":"I. Mohammed, B. Muhammad","doi":"10.7176/cmr/11-9-03","DOIUrl":"https://doi.org/10.7176/cmr/11-9-03","url":null,"abstract":"This study investigated the effects of Jigsaw IV Cooperative Learning Strategy (J4CLS) on Students’ Academic Performance in Organic Chemistry in Zaria Education Zone. A pretest and posttest Quasi-experimental research design was used for the study which featured two groups (Experimental and Control groups). The experimental group was exposed to Jigsaw IV Cooperative Learning Strategy while the control group was taught using Conventional Method of Teaching (CMT). A Sample sizes of 234 students selected from two Senior Secondary Schools in Zaria Education zone was used as the study sample, drawn from a population of 11 schools with a total of 1154 students. The two schools selected, were pretested, to find their academic equivalence before the treatment. The instrument developed was Organic Chemistry Performance Test (OCPT) with a reliability coefficient of 0.88 was used for data collection. The data collected was analyzed using Mean scores, Standard deviation, Analysis of Covariate (ANCOVA) and t-test statistics at P≤ 0.05 level of significance. The findings indicated that, there is significant difference between the mean performance scores of science students taught Organic Chemistry concepts with Jigsaw IV Cooperative Learning Strategy and their counterparts taught with CMT in Zaria Education zone. However, students’ gender had no influence on their academic performance. Based on the findings, it was recommended among others that Chemistry teachers should incorporate into main streams of pedagogy in the teaching of chemistry at Senior Secondary Schools the use of Jigsaw IV Cooperative Learning Strategy to improve students’ cognitive and affective outcomes among others. Keywords: Jigsaw IV Cooperative Learning Strategy, Academic Performance, Organic Chemistry DOI : 10.7176/CMR/11-9-03 Publication date: November 30 th 2019","PeriodicalId":9724,"journal":{"name":"chemistry and materials research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76310718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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