The unsaturated zone of floodplain wetlands in the White Volta River basin provides an inextricable link between basin hydrology and the sustenance of plant growth. The HYDRUS-1D model was used to derive water budgets and to estimate fluxes to understand the hydrological complexities of these wetland systems. The model result indicates Spatio-temporal variation in the volume of vertical fluxes. In 2005, the estimate for average simulated flux was 0.29 cm/month in June and 1.23 cm/month in July. Consequently, the hydraulic head increased from 138.94 m to 139.30 m for the period from June to July 2005. For all sample sites, the increase in hydraulic head occurs within July and October, coinciding with high surface water fluxes. From the calculated water balance, the average monthly estimate of bottom flux was 0.01 cm/month for 2004 and 1.1 cm/month for 2005. The flow through the unsaturated zone and discharging into the subsurface water system has a high dependency on both the soil structure and the volume of water infiltrating through the surface; the highest discharge is within the period of highest water input.
{"title":"Modeling Unsaturated Zone Water Movement in the Floodplain Wetlands of the Volta Basin","authors":"B. Nyarko","doi":"10.5539/enrr.v10n3p1","DOIUrl":"https://doi.org/10.5539/enrr.v10n3p1","url":null,"abstract":"The unsaturated zone of floodplain wetlands in the White Volta River basin provides an inextricable link between basin hydrology and the sustenance of plant growth. The HYDRUS-1D model was used to derive water budgets and to estimate fluxes to understand the hydrological complexities of these wetland systems. The model result indicates Spatio-temporal variation in the volume of vertical fluxes. In 2005, the estimate for average simulated flux was 0.29 cm/month in June and 1.23 cm/month in July. Consequently, the hydraulic head increased from 138.94 m to 139.30 m for the period from June to July 2005. For all sample sites, the increase in hydraulic head occurs within July and October, coinciding with high surface water fluxes. From the calculated water balance, the average monthly estimate of bottom flux was 0.01 cm/month for 2004 and 1.1 cm/month for 2005. The flow through the unsaturated zone and discharging into the subsurface water system has a high dependency on both the soil structure and the volume of water infiltrating through the surface; the highest discharge is within the period of highest water input.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"26 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83505267","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}
It was sought, in this research, to evaluate the effects of fertilizer solutions on water retention by hydrogel as well as if the application methods and fertilizers affect water retention when the hydrogel is added to the soil. In laboratory works (experiment 1), the completely randomized design was used taking into account four treatments: distilled water; Urea (UR – 2.0 g L-1 ) and Magnesium Sulfate + Monoammonium Phosphate (MS + MAP – 2.0 g L-1 each). Regarding the experiment 2, considering soil columns, a 2x3x2 factorial was used, corresponding to two hydrogel application methods: dry and mixed to the soil or diluted in water and concentrated in the center of the column; three fertilizer solutions: distilled water, UR (2.0 g L-1 ) and MS + MAP (2.0 g L-1 each) with two cycles and three repetitions. An additional witness (hydrogel free) was also added. Total water volume absorbed by hydrogel, volume stored in the soil after each cycle, pH and electrical conductivity (EC) of leached solutions were all analyzed. The MS solution was the one who impacted the most the water absorption by the hydrogel, principally when the hydrogel was not present in the soil. The pH and EC of leached solutions evidenced the fertilizer solutions salinity.
本研究旨在评价肥料溶液对水凝胶保水性的影响，以及当水凝胶加入土壤时，施用方法和肥料是否会影响水凝胶的保水性。在实验室作品(实验1)中，采用完全随机设计，考虑四种处理:蒸馏水;尿素(UR - 2.0 g L-1)和硫酸镁+磷酸一铵(MS + MAP - 2.0 g L-1)。实验2考虑土柱，采用2x3x2因子，对应两种水凝胶施药方法:干燥混合到土中或用水稀释浓缩到柱中央;3种肥料溶液:蒸馏水、UR (2.0 g L-1)和MS + MAP(各2.0 g L-1)，循环2次，重复3次。另外还添加了一种见证人(不含水凝胶)。分析了水凝胶吸附总水量、各循环后土壤中贮存水量、浸出液的pH值和电导率(EC)。质谱溶液对水凝胶的吸水性影响最大，特别是当水凝胶不存在于土壤中时。浸出液的pH值和EC值反映了肥料溶液的盐度。
{"title":"Water Absorption by Hydrogel Using Fertilizers","authors":"J. F. Sobrinho, F.E.L. Barbosa","doi":"10.5539/enrr.v10n2p26","DOIUrl":"https://doi.org/10.5539/enrr.v10n2p26","url":null,"abstract":"It was sought, in this research, to evaluate the effects of fertilizer solutions on water retention by hydrogel as well as if the application methods and fertilizers affect water retention when the hydrogel is added to the soil. In laboratory works (experiment 1), the completely randomized design was used taking into account four treatments: distilled water; Urea (UR – 2.0 g L-1 ) and Magnesium Sulfate + Monoammonium Phosphate (MS + MAP – 2.0 g L-1 each). Regarding the experiment 2, considering soil columns, a 2x3x2 factorial was used, corresponding to two hydrogel application methods: dry and mixed to the soil or diluted in water and concentrated in the center of the column; three fertilizer solutions: distilled water, UR (2.0 g L-1 ) and MS + MAP (2.0 g L-1 each) with two cycles and three repetitions. An additional witness (hydrogel free) was also added. Total water volume absorbed by hydrogel, volume stored in the soil after each cycle, pH and electrical conductivity (EC) of leached solutions were all analyzed. The MS solution was the one who impacted the most the water absorption by the hydrogel, principally when the hydrogel was not present in the soil. The pH and EC of leached solutions evidenced the fertilizer solutions salinity.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"23 1","pages":"26"},"PeriodicalIF":0.0,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91209929","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}
T. V. Phuong, L. X. Sinh, Le Duc Cuong, Dang Cong Xuong, B. M. Hà
The study of community tourism development based on green economy model is the focus of this paper. The research is implemented in Viet Hai - a commune of Cat Hai island district, Hai Phong city, Vietnam. In order to evaluate, select and develop this model in the locality, a number of research methods have been applied such as: Method of seminars, expert consult, group system of sampling methods, fertilizer analyzing laboratories and methods of interviewing and collecting socio-economic data. The research outcome is given that, the community tourism based on green economy is a type of economic model that contributes not only on the local socio-economic development, but also surmounting the seasonal tourism situation, and maximizing the region's potential and strengths. The model chosen was the communitys based tourism model, with the participation of 1/3 of households in Viet Hai commune. The model has a management board with applicable rules and regulations to objects such as households, tourism operators and Viet Hai visitors. The model has been oriented towards exploiting the landscape values associated with environmental protection programs, especially towards the point-based community tourism model of Cat Ba district – which say “no” to single-use plastic products. This tourism model has created the tourism products that are different from the existing models in Cat Ba (Hai Phong), creating channels to link with tourists to attract more visitors to Viet Hai increasingly to the year.
{"title":"Community Tourism Development in Viet Hai Commune (Cat Ba, Hai Phong City, Viet Nam) Under the Green Economy Model","authors":"T. V. Phuong, L. X. Sinh, Le Duc Cuong, Dang Cong Xuong, B. M. Hà","doi":"10.5539/enrr.v10n2p43","DOIUrl":"https://doi.org/10.5539/enrr.v10n2p43","url":null,"abstract":"The study of community tourism development based on green economy model is the focus of this paper. The research is implemented in Viet Hai - a commune of Cat Hai island district, Hai Phong city, Vietnam. In order to evaluate, select and develop this model in the locality, a number of research methods have been applied such as: Method of seminars, expert consult, group system of sampling methods, fertilizer analyzing laboratories and methods of interviewing and collecting socio-economic data. The research outcome is given that, the community tourism based on green economy is a type of economic model that contributes not only on the local socio-economic development, but also surmounting the seasonal tourism situation, and maximizing the region's potential and strengths. The model chosen was the communitys based tourism model, with the participation of 1/3 of households in Viet Hai commune. The model has a management board with applicable rules and regulations to objects such as households, tourism operators and Viet Hai visitors. The model has been oriented towards exploiting the landscape values associated with environmental protection programs, especially towards the point-based community tourism model of Cat Ba district – which say “no” to single-use plastic products. This tourism model has created the tourism products that are different from the existing models in Cat Ba (Hai Phong), creating channels to link with tourists to attract more visitors to Viet Hai increasingly to the year.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"1 1","pages":"43-53"},"PeriodicalIF":0.0,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88862386","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}
γ-Al2O3 supported Cu, Cu-Zn and Cu-Ni-Fe-Zn oxide catalysts were prepared using leachate transition metal nitrate and sulfate aqueous solutions from commercial spent catalysts. A bench-scale rig was used to investigate the combustion activity of these catalysts toward methane or ethane in the air stream (1000 ppmv) at a space velocity of 20,000 h-1. The Cu-Ni-Fe-Zn oxides/γ-Al2O3 catalyst proved to be the most active catalyst for the combustion of methane in the temperature range 290-575°C and of ethane in the lower temperature range of 275-525oC as compared to Cu and Cu-Zn oxide loaded catalysts. X-ray powder diffractograms indicated that the metal oxide species were highly dispersed or amorphous on the alumina surface in all the catalysts except for the detection of a minority phase of monoclinic CuO on the Cu-containing mono-metallic catalysts. The co-existence of ZnO in the CuO catalysts suppresses the activity of the copper oxide species and, therefore, the conversion of methane or ethane was reduced. The present research endeavor provides proof-of-concept that relatively inexpensive metal oxide-based heterogeneous catalysts for VOCs abatement can be recovered from spent catalysts. Hence, environmental and health threats of improper handling of VOCs or spent catalysts may be alleviated.
利用工业废催化剂的渗滤液过渡金属硝酸盐和硫酸盐水溶液制备了γ-Al2O3负载型Cu、Cu- zn和Cu- ni - fe - zn氧化物催化剂。在一个实验平台上，研究了这些催化剂在空气流(1000 ppmv)中，在20,000 h-1的空速下对甲烷或乙烷的燃烧活性。与Cu和Cu- zn氧化物催化剂相比，Cu- ni - fe - zn氧化物/γ-Al2O3催化剂在290 ~ 575℃范围内对甲烷的燃烧和275 ~ 525℃范围内对乙烷的燃烧表现出较强的催化活性。x射线粉末衍射图表明，除了在含cu的单金属催化剂上检测到少量单斜相CuO外，所有催化剂的金属氧化物在氧化铝表面高度分散或无定形。氧化锌在CuO催化剂中的共存抑制了氧化铜的活性，从而降低了甲烷或乙烷的转化率。目前的研究努力提供了概念证明，相对便宜的金属氧化物基非均相催化剂可以从废催化剂中回收，用于减少voc。因此，不当处理挥发性有机化合物或废催化剂对环境和健康的威胁可能会减轻。
{"title":"Catalytic Abatement of VOCs: Aerobic Combustion of Methane or Ethane over Alumina-Supported Metal Oxides Recovered from Spent Catalysts","authors":"S. Tahir, H. Askari","doi":"10.5539/enrr.v10n2p33","DOIUrl":"https://doi.org/10.5539/enrr.v10n2p33","url":null,"abstract":"γ-Al2O3 supported Cu, Cu-Zn and Cu-Ni-Fe-Zn oxide catalysts were prepared using leachate transition metal nitrate and sulfate aqueous solutions from commercial spent catalysts. A bench-scale rig was used to investigate the combustion activity of these catalysts toward methane or ethane in the air stream (1000 ppmv) at a space velocity of 20,000 h-1. The Cu-Ni-Fe-Zn oxides/γ-Al2O3 catalyst proved to be the most active catalyst for the combustion of methane in the temperature range 290-575°C and of ethane in the lower temperature range of 275-525oC as compared to Cu and Cu-Zn oxide loaded catalysts. X-ray powder diffractograms indicated that the metal oxide species were highly dispersed or amorphous on the alumina surface in all the catalysts except for the detection of a minority phase of monoclinic CuO on the Cu-containing mono-metallic catalysts. The co-existence of ZnO in the CuO catalysts suppresses the activity of the copper oxide species and, therefore, the conversion of methane or ethane was reduced. The present research endeavor provides proof-of-concept that relatively inexpensive metal oxide-based heterogeneous catalysts for VOCs abatement can be recovered from spent catalysts. Hence, environmental and health threats of improper handling of VOCs or spent catalysts may be alleviated.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"75 5 1","pages":"33"},"PeriodicalIF":0.0,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89215519","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}
Mopane worms (Gonimbrasia belina) are an important source of food and income for households in Northern Namibia. However, their access and availability in many areas have declined, mainly due to climate change and human activities. This has affected many households’ livelihoods, making them vulnerable to poverty and food insecurity. With these factors in mind, this study sought to identify the extent to which the availability and distribution of mopane worms are influenced in the Tsandi and Okahao constituencies. The study used structured questionnaires to collect information from households in the study area, to interview key informants, and to carry out group discussions. A total of 70 households and 6 key informants were interviewed, along with 4 focus group discussions that were carried out to elicit perceptions, and to obtain views on the availability of mopane worms, and possible causes of the decline in the study area. Data were analysed using descriptive statistics, while GIS was used to determine trends in vegetation cover, temperature and rainfall in the area. The rainfall trend indicates variability, with a generally declining trend. A slight increase in temperature has been observed too. Vegetation showed a browning trend in the study area, indicating declining habitats of mopane worms. The results have indicated that more women depend on mopane worms for survival, mainly as a source of income. Thus the decline in their availability greatly affects their food sources and their income diversification opportunities. Trading was found to be an important form of employment for the unemployed rural people, but with the potential to generate higher income levels that can improve their livelihoods. Moreover, despite the climatic factors, human activities seemed to indicate a greater influence on the availability of mopane worms, due to activities such as overharvesting, land clearing for agriculture and household use/fencing. Thus, there is a greater need to control the harvesting of mopane worms and to control tree cutting activities in order to reduce the impacts of climatic and non-climatic factors on their availability.
{"title":"Effects of Climatic Variability and Non-Climatic Factors on Mopane Worms’ (Gonimbrasia Belina) Distribution and Livelihood Options in North Central Namibia","authors":"C. Togarepi, E. Nashidengo, N. Siyambango","doi":"10.5539/ENRR.V10N2P14","DOIUrl":"https://doi.org/10.5539/ENRR.V10N2P14","url":null,"abstract":"Mopane worms (Gonimbrasia belina) are an important source of food and income for households in Northern Namibia. However, their access and availability in many areas have declined, mainly due to climate change and human activities. This has affected many households’ livelihoods, making them vulnerable to poverty and food insecurity. With these factors in mind, this study sought to identify the extent to which the availability and distribution of mopane worms are influenced in the Tsandi and Okahao constituencies. The study used structured questionnaires to collect information from households in the study area, to interview key informants, and to carry out group discussions. A total of 70 households and 6 key informants were interviewed, along with 4 focus group discussions that were carried out to elicit perceptions, and to obtain views on the availability of mopane worms, and possible causes of the decline in the study area. Data were analysed using descriptive statistics, while GIS was used to determine trends in vegetation cover, temperature and rainfall in the area. The rainfall trend indicates variability, with a generally declining trend. A slight increase in temperature has been observed too. Vegetation showed a browning trend in the study area, indicating declining habitats of mopane worms. The results have indicated that more women depend on mopane worms for survival, mainly as a source of income. Thus the decline in their availability greatly affects their food sources and their income diversification opportunities. Trading was found to be an important form of employment for the unemployed rural people, but with the potential to generate higher income levels that can improve their livelihoods. Moreover, despite the climatic factors, human activities seemed to indicate a greater influence on the availability of mopane worms, due to activities such as overharvesting, land clearing for agriculture and household use/fencing. Thus, there is a greater need to control the harvesting of mopane worms and to control tree cutting activities in order to reduce the impacts of climatic and non-climatic factors on their availability.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"19 1","pages":"14"},"PeriodicalIF":0.0,"publicationDate":"2020-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84304783","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 article reports on use of advanced Near-Field—Far-Field software for assessing short- versus long-duration data obtained minute-by-minute at two distances from a small source of an evaporating solvent located in an isolated subsurface structure (a type of confined space) accessed through a manhole containing one or two opening(s). The software uses this data to predict worker exposure to airborne chemical substances. Initial flash-off of volatile components was readily visible in graphs prepared from some tests and especially so in initial output from the calibration utility contained in the modelling software. The calibration utility orients the mathematics of the software to measured data. The calibration utility indicated constant magnitude from longer-duration emissions consistent with constant composition. Source characterization of emissions from solvents containing multiple ingredients and constant initial mass deserves careful consideration because initial emissions may not represent overall behavior. This situation indicates the potential to bias predictions of worker and other types of exposure utilizing the same mathematics. This is especially the case during source characterization using measurements of short duration. This study advocates for further investigation to develop guidelines for source characterization during use of modelling software that minimize the potential for error in exposure assessment.
{"title":"Short-Duration Characterization of Source Emissions for Use in Predictive Software Models to Assess Worker Exposure: A Note of Caution","authors":"T. McManus, A. Haddad","doi":"10.5539/enrr.v10n2p1","DOIUrl":"https://doi.org/10.5539/enrr.v10n2p1","url":null,"abstract":"This article reports on use of advanced Near-Field—Far-Field software for assessing short- versus long-duration data obtained minute-by-minute at two distances from a small source of an evaporating solvent located in an isolated subsurface structure (a type of confined space) accessed through a manhole containing one or two opening(s). The software uses this data to predict worker exposure to airborne chemical substances. Initial flash-off of volatile components was readily visible in graphs prepared from some tests and especially so in initial output from the calibration utility contained in the modelling software. The calibration utility orients the mathematics of the software to measured data. The calibration utility indicated constant magnitude from longer-duration emissions consistent with constant composition. Source characterization of emissions from solvents containing multiple ingredients and constant initial mass deserves careful consideration because initial emissions may not represent overall behavior. This situation indicates the potential to bias predictions of worker and other types of exposure utilizing the same mathematics. This is especially the case during source characterization using measurements of short duration. This study advocates for further investigation to develop guidelines for source characterization during use of modelling software that minimize the potential for error in exposure assessment.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"13 3 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2020-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77559704","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}
Potato (Solanum tuberosum) is the world’s third most important food crop. However, potato productivity is very low in acidic soils that cover about 50% of the arable land in the world. Therefore, the aim of this study was to evaluate the effect of sole and integrated farmyard manure (FYM) and different types mineral fertilizers on yield, yield components and economic returns of potato in acidic soil of Ethiopia. Six treatments: 1) Control (without fertilizer), 2) sole application of the recommended NP (RNP) fertilizer (11 kg/ha N and 40 kg/ha P), 3) sole FYM (28.8 t/ha FYM), 4) half dose of recommended NP fertilizer and half dose of the FYM, 5) blended fertilizer formulated as 17.3 kg N, 34.7 kg P2O5, 7.41 kg S, 2.23 kg Zn, 0.3 kg B + 100 kg/ha), and 6) half blended and half FYM, were arranged in a randomized complete block design. The results revealed that potato plants amended with sole blended fertilizer, and integrated FYM and mineral fertilizers doubled fresh tuber yield as compared to the control. The RNP fertilizer gave the lowest (α < 0.05) marketable potato yields of all the fertilizer treatments. Applications of sole blended or integrated FYM and mineral fertilizers resulted in the highest net benefit with acceptable marginal rate of return. Integrated use of FYM and mineral fertilizers is crucial for improved and sustained smallholder potato production in acidic soils. Further studies are required to examine the long-term effects of blended fertilizers on soil properties.
马铃薯(Solanum tuberosum)是世界第三大粮食作物。然而，在酸性土壤中，马铃薯的产量非常低，而酸性土壤覆盖了世界上约50%的可耕地。因此，本研究旨在评价单一和综合农家肥(FYM)与不同类型矿质肥对埃塞俄比亚酸性土壤马铃薯产量、产量构成及经济效益的影响。6个处理:1)对照(不施肥)，2)单施推荐NP (RNP)肥(11 kg/ hm2 N和40 kg/ hm2 P)， 3)单施FYM (28.8 t/ hm2 FYM)， 4)推荐NP肥和FYM肥各施一半，5)混合肥料配制为17.3 kg N、34.7 kg P2O5、7.41 kg S、2.23 kg Zn、0.3 kg B + 100 kg/ hm2, 6)半混合半FYM。结果表明，马铃薯单施混肥，配施矿肥，鲜块茎产量比对照提高了一倍。在所有施肥处理中，RNP肥的可售马铃薯产量最低(α < 0.05)。施用单一混合或综合化肥和矿物肥料产生了最高的净效益和可接受的边际回报率。综合使用化肥和矿质肥料对于改善和维持酸性土壤中小农马铃薯生产至关重要。需要进一步的研究来检验混合肥料对土壤性质的长期影响。
{"title":"Integrated Application of Organic and Blended Mineral Fertilizers Improves Potato Productivity and Income for Smallholder Farmers in Acidic Soils","authors":"T. Girma, B. Biazin, S. Beyene, B. Lemaga","doi":"10.5539/enrr.v10n1p61","DOIUrl":"https://doi.org/10.5539/enrr.v10n1p61","url":null,"abstract":"Potato (Solanum tuberosum) is the world’s third most important food crop. However, potato productivity is very low in acidic soils that cover about 50% of the arable land in the world. Therefore, the aim of this study was to evaluate the effect of sole and integrated farmyard manure (FYM) and different types mineral fertilizers on yield, yield components and economic returns of potato in acidic soil of Ethiopia. Six treatments: 1) Control (without fertilizer), 2) sole application of the recommended NP (RNP) fertilizer (11 kg/ha N and 40 kg/ha P), 3) sole FYM (28.8 t/ha FYM), 4) half dose of recommended NP fertilizer and half dose of the FYM, 5) blended fertilizer formulated as 17.3 kg N, 34.7 kg P2O5, 7.41 kg S, 2.23 kg Zn, 0.3 kg B + 100 kg/ha), and 6) half blended and half FYM, were arranged in a randomized complete block design. The results revealed that potato plants amended with sole blended fertilizer, and integrated FYM and mineral fertilizers doubled fresh tuber yield as compared to the control. The RNP fertilizer gave the lowest (α < 0.05) marketable potato yields of all the fertilizer treatments. Applications of sole blended or integrated FYM and mineral fertilizers resulted in the highest net benefit with acceptable marginal rate of return. Integrated use of FYM and mineral fertilizers is crucial for improved and sustained smallholder potato production in acidic soils. Further studies are required to examine the long-term effects of blended fertilizers on soil properties.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"17 1","pages":"61"},"PeriodicalIF":0.0,"publicationDate":"2020-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73541935","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}
Assessing exposure to particulate emissions during arc welding is an important consideration in assuring compliance with regulatory requirements. This study examined welding emissions during argon-shielded GMAW (MIG welding) processes involving aluminum alloys in a shipbuilding environment using traditional methods of air sampling (portable pumps and closed-face cassettes containing PVC filters.) Current requirements for exposure determination (inhalable, respirable and total particulates) necessitate three simultaneous samples, a very onerous imposition on worker safety and comfort. Application of a conversion factor published in the literature can considerably simplify this situation through use of a single sampler, the conventional closed face cassette. This approach provides a first-level means of evaluation and is especially useful where exposure levels are low compared to regulatory Exposure Limits. Assessment of exposure to chromium, magnesium and manganese may require additional consideration because of the necessity for simultaneous evaluation against TLVs for inhalable and respirable particulates and different oxidation states. Results strongly suggest that beryllium and/or chromium VI and possibly manganese dominate consideration about exposure and control measures (Critical Particulate Contaminant). This results from the difficulty of analysis created by the combination of extremely small Exposure Limits, presence of these elements in the alloy in trace to very small quantities and uncertainty associated with detectability in standard air samples. Resolving this question requires collection and analysis of bulk quantities of welding fume to improve the mathematics associated with detectability. Determination of the Critical Particulate Contaminant considerably simplifies future evaluation and focuses follow-up action in the appropriate direction.
{"title":"Critical Particulate Contaminant(s) Generated during Arc Welding on Aluminum Alloys","authors":"T. McManus, A. Haddad","doi":"10.5539/enrr.v10n1p43","DOIUrl":"https://doi.org/10.5539/enrr.v10n1p43","url":null,"abstract":"Assessing exposure to particulate emissions during arc welding is an important consideration in assuring compliance with regulatory requirements. This study examined welding emissions during argon-shielded GMAW (MIG welding) processes involving aluminum alloys in a shipbuilding environment using traditional methods of air sampling (portable pumps and closed-face cassettes containing PVC filters.) Current requirements for exposure determination (inhalable, respirable and total particulates) necessitate three simultaneous samples, a very onerous imposition on worker safety and comfort. Application of a conversion factor published in the literature can considerably simplify this situation through use of a single sampler, the conventional closed face cassette. This approach provides a first-level means of evaluation and is especially useful where exposure levels are low compared to regulatory Exposure Limits. Assessment of exposure to chromium, magnesium and manganese may require additional consideration because of the necessity for simultaneous evaluation against TLVs for inhalable and respirable particulates and different oxidation states. Results strongly suggest that beryllium and/or chromium VI and possibly manganese dominate consideration about exposure and control measures (Critical Particulate Contaminant). This results from the difficulty of analysis created by the combination of extremely small Exposure Limits, presence of these elements in the alloy in trace to very small quantities and uncertainty associated with detectability in standard air samples. Resolving this question requires collection and analysis of bulk quantities of welding fume to improve the mathematics associated with detectability. Determination of the Critical Particulate Contaminant considerably simplifies future evaluation and focuses follow-up action in the appropriate direction.","PeriodicalId":11699,"journal":{"name":"Environment and Natural Resources Research","volume":"46 1","pages":"43"},"PeriodicalIF":0.0,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77571105","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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