This research paper depicts the experimental investigation of the impact of stone dust as an admixture on the geotechnical characteristics of expansive soils that shrink and swell during the wet and dry seasons. As a result, expansive soil causes the differential settlement of structures. Thus the stabilization of expansive soil is important to overcome potential pavement failure. For this purpose research studies were carried out on the reuse of stone industry wastage for the improvement of expansive soil. Also, this research is beneficial to utilize the stone dust waste for strengthening the soil and making the environment pollution-free. Stone dust was used to stabilize the geotechnical characteristics of the weak soil such as shear strength, unconfined compressive strength (UCS), index properties, maximum dry density (MDD), optimum moisture content (OMC), and California bearing ratio (CBR). The percentages of stone dust employed in the studies were 0%, 7%, 14%, 21%, and 28% by dry weight of soil, which substantially reduced the soil's swelling properties. The results show significant improvements in the desirable geotechnical characteristics of the expansive soil. The optimal quantity of stone dust was concluded based on the findings for treating the subgrade of weaker expansive soil.
{"title":"Re-utilization of Stone Industry Waste Materials for Stabilization of Expansive Soil","authors":"Umar Zada, K. Haleem, Asim Abbas","doi":"10.24949/njes.v14i2.670","DOIUrl":"https://doi.org/10.24949/njes.v14i2.670","url":null,"abstract":"This research paper depicts the experimental investigation of the impact of stone dust as an admixture on the geotechnical characteristics of expansive soils that shrink and swell during the wet and dry seasons. As a result, expansive soil causes the differential settlement of structures. Thus the stabilization of expansive soil is important to overcome potential pavement failure. For this purpose research studies were carried out on the reuse of stone industry wastage for the improvement of expansive soil. Also, this research is beneficial to utilize the stone dust waste for strengthening the soil and making the environment pollution-free. Stone dust was used to stabilize the geotechnical characteristics of the weak soil such as shear strength, unconfined compressive strength (UCS), index properties, maximum dry density (MDD), optimum moisture content (OMC), and California bearing ratio (CBR). The percentages of stone dust employed in the studies were 0%, 7%, 14%, 21%, and 28% by dry weight of soil, which substantially reduced the soil's swelling properties. The results show significant improvements in the desirable geotechnical characteristics of the expansive soil. The optimal quantity of stone dust was concluded based on the findings for treating the subgrade of weaker expansive soil.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116924045","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}
Escalating energy demands, scarcity of conventional energy resources and environmental concerns are the key to fuel production through water splitting. Various electrocatalysts have been reported, considering the cost effectiveness, stability and OER (oxygen evolution reaction) activity. In the same context, porous hybrid NiO-NiFe2O4/MWCNTs based nanocomposite as an OER electrocatalyst, has been investigated in the current study. The synthesis has been accomplished via co-precipitation using Tween as a surfactant. Characterization and electrochemical study for water electrolysis using synthesized electrocatalyst deposited glassy Carbon (GC) electrode as anode was carried out using relevant tools. Iron-doped Nickel oxide nanoparticles were synthesized recognizing excellent oxygen evolution activity of NiO and its increase in conductivity with Fe incorporation due to its higher electropositivity. Nanocomposites were synthesized by incorporating upto 20% weight percent MWCNT (Multiwall carbon nanotubes). High surface to volume ratios, stability and excellent conductivity of MWCNTs furthermore, reduction of crystallite sized due to their incorporation enhanced the performance of the electrocatalyst significantly. Hybrid formation of NiO and NiFe2O4 at a certain calcination temperature was also found to be the reason for enhanced OER activity due to the increased grain boundaries. Porous NiO-NiFe2O4/MWCNTs with 10% MWCNTs concentration outperformed with 35mA/cm2 of current density at 1.8V in alkaline media.
{"title":"Electrochemical Water Splitting Using NiO-NiFe2O4/MWCNTs Nanocomposite as Electrocatalyst","authors":"Rida Noor, M. Shahid, F. Khan, M. Umer","doi":"10.24949/njes.v14i2.660","DOIUrl":"https://doi.org/10.24949/njes.v14i2.660","url":null,"abstract":"Escalating energy demands, scarcity of conventional energy resources and environmental concerns are the key to fuel production through water splitting. Various electrocatalysts have been reported, considering the cost effectiveness, stability and OER (oxygen evolution reaction) activity. In the same context, porous hybrid NiO-NiFe2O4/MWCNTs based nanocomposite as an OER electrocatalyst, has been investigated in the current study. The synthesis has been accomplished via co-precipitation using Tween as a surfactant. Characterization and electrochemical study for water electrolysis using synthesized electrocatalyst deposited glassy Carbon (GC) electrode as anode was carried out using relevant tools. Iron-doped Nickel oxide nanoparticles were synthesized recognizing excellent oxygen evolution activity of NiO and its increase in conductivity with Fe incorporation due to its higher electropositivity. Nanocomposites were synthesized by incorporating upto 20% weight percent MWCNT (Multiwall carbon nanotubes). High surface to volume ratios, stability and excellent conductivity of MWCNTs furthermore, reduction of crystallite sized due to their incorporation enhanced the performance of the electrocatalyst significantly. Hybrid formation of NiO and NiFe2O4 at a certain calcination temperature was also found to be the reason for enhanced OER activity due to the increased grain boundaries. Porous NiO-NiFe2O4/MWCNTs with 10% MWCNTs concentration outperformed with 35mA/cm2 of current density at 1.8V in alkaline media.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128227258","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. U. Farooq, Sumayya, M. Umer Iqbal, Ishrat Asghar, Mujtaba Ikram, Sajid Butt
The series of Bi2O2Se-Ag2Se composites were synthesized by two step solid state reaction followed by Spark plasma sintering. To optimize their thermal transport properties, different weight percent (wt. %) of silver i-e, 10%, 15% and 20%, was added. The room temperature X-ray diffraction (XRD) and high temperature XRD was used to investigate the crystalline phases, whereas the morphological study was conducted through FESEM. The thermal transport properties were evaluated from 323 K to 773 K, to study the effect of silver addition on thermal conductivity of all the composite samples. The reduced thermal conductivity of the composite with decreasing Ag contents is might be attributed to increase of the Ag2Se and Bi2O3 nano-inclusions in Bi2O2Se multi-phase-system that increased the phonon scattering regions and reduced the overall thermal conductivity significantly, up to 54 % for BA15SO as compared to that of BA20CO at 473 K.
采用两步固相反应和放电等离子烧结法制备了Bi2O2Se-Ag2Se系列复合材料。为了优化它们的热输运性能，添加不同重量百分比(wt. %)的银i-e, 10%， 15%和20%。采用室温x射线衍射(XRD)和高温x射线衍射(XRD)对其进行了晶相分析，并用FESEM对其形貌进行了研究。在323 K ~ 773 K范围内考察了复合材料的热输运性能，研究了银的加入对复合材料导热性能的影响。随着Ag含量的降低，复合材料的导热系数降低可能是由于Bi2O2Se多相体系中Ag2Se和Bi2O3纳米夹杂物的增加，增加了声子散射区域，显著降低了总导热系数，在473 K时，BA15SO的导热系数比BA20CO降低了54%。
{"title":"Thermal Transport Properties of Bi2O2Se-Ag2Se Hybrid Structures","authors":"M. U. Farooq, Sumayya, M. Umer Iqbal, Ishrat Asghar, Mujtaba Ikram, Sajid Butt","doi":"10.24949/njes.v14i2.662","DOIUrl":"https://doi.org/10.24949/njes.v14i2.662","url":null,"abstract":"The series of Bi2O2Se-Ag2Se composites were synthesized by two step solid state reaction followed by Spark plasma sintering. To optimize their thermal transport properties, different weight percent (wt. %) of silver i-e, 10%, 15% and 20%, was added. The room temperature X-ray diffraction (XRD) and high temperature XRD was used to investigate the crystalline phases, whereas the morphological study was conducted through FESEM. The thermal transport properties were evaluated from 323 K to 773 K, to study the effect of silver addition on thermal conductivity of all the composite samples. The reduced thermal conductivity of the composite with decreasing Ag contents is might be attributed to increase of the Ag2Se and Bi2O3 nano-inclusions in Bi2O2Se multi-phase-system that increased the phonon scattering regions and reduced the overall thermal conductivity significantly, up to 54 % for BA15SO as compared to that of BA20CO at 473 K.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131036848","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 assembling process includes various techniques, out of which riveting has been employed most successfully in fields like construction of enormous structures, auto-motives, and most notably in the aerospace industry. This process includes marking, drilling followed by riveting. Furthermore, being a successful process, most of the aircraft structure is assembled using rivets. However, various factors contribute to the result. Therefore, the effect of riveting process parameters such as Sheet Thickness, Rivet Diameter, Rivet Type, and Riveting Sequence have been studied on responses, i.e., Deformation and Joint Load Capacity of lap joint composed of Aluminum Alloy sheets (LY-12) at T0 condition by sandwiching aerospace-grade sealant (XM-22B). Each of these parameters is studied on three levels and the experimental setup is designed using Response Surface Methodology (RSM). The main objective of this work is to demonstrate the effect of riveting parameters on lap joints with sealant and analyze the effect through careful measurement of deformation and joint load capacity of the test specimen. Finally, a variance analysis (ANOVA) is performed to identify significant factors influencing response parameters using Design Expert Software V-12.
{"title":"Impact of Riveting Parameters on Mechanical Properties of Aluminum Alloy (LY-12) Sealant Applied Lap Joint of an Aircraft","authors":"A. A. Qureshi","doi":"10.24949/NJES.V14I1.649","DOIUrl":"https://doi.org/10.24949/NJES.V14I1.649","url":null,"abstract":" The assembling process includes various techniques, out of which riveting has been employed most successfully in fields like construction of enormous structures, auto-motives, and most notably in the aerospace industry. This process includes marking, drilling followed by riveting. Furthermore, being a successful process, most of the aircraft structure is assembled using rivets. However, various factors contribute to the result. Therefore, the effect of riveting process parameters such as Sheet Thickness, Rivet Diameter, Rivet Type, and Riveting Sequence have been studied on responses, i.e., Deformation and Joint Load Capacity of lap joint composed of Aluminum Alloy sheets (LY-12) at T0 condition by sandwiching aerospace-grade sealant (XM-22B). Each of these parameters is studied on three levels and the experimental setup is designed using Response Surface Methodology (RSM). The main objective of this work is to demonstrate the effect of riveting parameters on lap joints with sealant and analyze the effect through careful measurement of deformation and joint load capacity of the test specimen. Finally, a variance analysis (ANOVA) is performed to identify significant factors influencing response parameters using Design Expert Software V-12.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125762714","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 safety of water is essential for life on earth. Drinking contaminated water can give rise to many health issues. Tohighlight the major causes of contamination in water, this study was carried out to determine the physicochemical andbacteriological quality of raw and chlorinated water. Raw and chlorinated water samples were obtained from three locations (zones) of a residential university (National University of Sciences and Technology, NUST). Ten physicochemicalparameters were analyzed (pH, Electrical conductivity, Turbidity, Dissolved oxygen, Hardness, Alkalinity, Total suspendedsolids, Total dissolved solids, Total organic carbon, and Chlorine (free & total)). Bacteriological analysis was performedthrough the MPN technique. The results showed that all the physicochemical parameters were found within the permissible limits set by WHO and PSDWQ for raw and chlorinated water, except TSS and Chlorine (free & total). The TSS of raw and chlorinated water ranged from 3.3-14.3mg/L and 8.7-12.7mg/L, greater than the permissible limits. The free Chlorine for both raw and chlorinated water ranged from 0.04-0.09mg/L and 0.06-0.07mg/L and total Chlorine for both raw and chlorinated water in the range 0.10-0.09mg/L and 0.22-0.24mg/L, respectively, which were far below the recommended limit required for water disinfection. The MPN index for raw and chlorinated water ranged from 23 to >23MPN/100ml and 16 to >23MPN/100ml, exceeding the permissible limits. The results concluded that the water, whether raw or chlorinated, was not fit for drinking purposes. Proper dosages of Chlorine and filtration techniques are required to make the water fit for consumption.
{"title":"Water quality assessment of Raw and Chlorinated drinking water of a Residential University","authors":"Huda M. Kamal, I. Hashmi","doi":"10.24949/NJES.V14I1.633","DOIUrl":"https://doi.org/10.24949/NJES.V14I1.633","url":null,"abstract":" The safety of water is essential for life on earth. Drinking contaminated water can give rise to many health issues. Tohighlight the major causes of contamination in water, this study was carried out to determine the physicochemical andbacteriological quality of raw and chlorinated water. Raw and chlorinated water samples were obtained from three locations (zones) of a residential university (National University of Sciences and Technology, NUST). Ten physicochemicalparameters were analyzed (pH, Electrical conductivity, Turbidity, Dissolved oxygen, Hardness, Alkalinity, Total suspendedsolids, Total dissolved solids, Total organic carbon, and Chlorine (free & total)). Bacteriological analysis was performedthrough the MPN technique. The results showed that all the physicochemical parameters were found within the permissible limits set by WHO and PSDWQ for raw and chlorinated water, except TSS and Chlorine (free & total). The TSS of raw and chlorinated water ranged from 3.3-14.3mg/L and 8.7-12.7mg/L, greater than the permissible limits. The free Chlorine for both raw and chlorinated water ranged from 0.04-0.09mg/L and 0.06-0.07mg/L and total Chlorine for both raw and chlorinated water in the range 0.10-0.09mg/L and 0.22-0.24mg/L, respectively, which were far below the recommended limit required for water disinfection. The MPN index for raw and chlorinated water ranged from 23 to >23MPN/100ml and 16 to >23MPN/100ml, exceeding the permissible limits. The results concluded that the water, whether raw or chlorinated, was not fit for drinking purposes. Proper dosages of Chlorine and filtration techniques are required to make the water fit for consumption.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126480793","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}
Outdoor insulator plays a vital role in high voltage transmission and distribution system. The performance and properties of outdoor insulator may severely affect due to various types of pollutants. The failure of insulation in high voltage system results in loss of supply and a huge loss of electrical energy to distribution utilities. In order to reduce power losses and provide a reliable power transmission, selection and design of insulators is very important. To monitor the condition and performance of outdoor insulator in contaminated conditions an appropriate diagnostic technique is required. In this paper various online and offline techniques for conditioning monitoring of outdoor insulators are reviewed under different contaminated conditions. To maintain the healthy environment, the condition monitoring of power line insulators is an important requirement. There are number of techniques that have been introduced to fulfil this requirement. Each technique used at different contaminated condition have their own pros and cons. The findings indicate that the most important effect on the surface of the insulators based on the contamination on the surface leakage current and the flashover voltage. This paper will help in the selection and design of condition monitoring techniques for high voltage outdoor insulator.
{"title":"Condition Monitoring of Outdoor High Voltage Insulators, Online and Offline Techniques: A review","authors":"Haseeb Faisal, A. Ali, M. Riaz","doi":"10.24949/NJES.V14I1.627","DOIUrl":"https://doi.org/10.24949/NJES.V14I1.627","url":null,"abstract":" Outdoor insulator plays a vital role in high voltage transmission and distribution system. The performance and properties of outdoor insulator may severely affect due to various types of pollutants. The failure of insulation in high voltage system results in loss of supply and a huge loss of electrical energy to distribution utilities. In order to reduce power losses and provide a reliable power transmission, selection and design of insulators is very important. To monitor the condition and performance of outdoor insulator in contaminated conditions an appropriate diagnostic technique is required. In this paper various online and offline techniques for conditioning monitoring of outdoor insulators are reviewed under different contaminated conditions. To maintain the healthy environment, the condition monitoring of power line insulators is an important requirement. There are number of techniques that have been introduced to fulfil this requirement. Each technique used at different contaminated condition have their own pros and cons. The findings indicate that the most important effect on the surface of the insulators based on the contamination on the surface leakage current and the flashover voltage. This paper will help in the selection and design of condition monitoring techniques for high voltage outdoor insulator.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121488755","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}
Due to high biocompatibility, bioactivity, and natural occurrence in bones and teeth, synthetic calcium hydroxyapatite (CaHAp) is a widely applied biomaterial in tissue engineering, including orthopedic surgery and dentistry. However, the brittle nature and low strength reduce its durability, which can be improved by doping metal ions. Rubidium (Rb) is an essential trace element that works as an antibacterial agent in the human body; therefore, it can be doped in synthetic Ca-HAp to promote its durability. In this work, Rb-doped calcium hydroxyapatite (Rb-HAp) nanoparticles are synthesized by the coprecipitation method at low temperatures. Phase purity, crystallinity, doping level, and mechanical properties are investigated by X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), and micro-hardness tester. It is observed that a minute quantity (≈ 0.02%) of Rb remained in the apatite structure when 5% of Rb+ is doped via in situ method. Moreover, small dopant concentration did not affect the crystal structure and the tensile strength of HAp.
{"title":"Synthesis of Rubidium-doped Calcium Hydroxyapatite Nanoparticles for Biomedical Applications","authors":"A. Nisar, S. Iqbal, M. Anjum, M. Shafique","doi":"10.24949/NJES.V14I1.644","DOIUrl":"https://doi.org/10.24949/NJES.V14I1.644","url":null,"abstract":" Due to high biocompatibility, bioactivity, and natural occurrence in bones and teeth, synthetic calcium hydroxyapatite (CaHAp) is a widely applied biomaterial in tissue engineering, including orthopedic surgery and dentistry. However, the brittle nature and low strength reduce its durability, which can be improved by doping metal ions. Rubidium (Rb) is an essential trace element that works as an antibacterial agent in the human body; therefore, it can be doped in synthetic Ca-HAp to promote its durability. In this work, Rb-doped calcium hydroxyapatite (Rb-HAp) nanoparticles are synthesized by the coprecipitation method at low temperatures. Phase purity, crystallinity, doping level, and mechanical properties are investigated by X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), and micro-hardness tester. It is observed that a minute quantity (≈ 0.02%) of Rb remained in the apatite structure when 5% of Rb+ is doped via in situ method. Moreover, small dopant concentration did not affect the crystal structure and the tensile strength of HAp.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130502578","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}
A. Chandio, A. Shah, I. A. Channa, S. Abro, Y. Raza, M. Rizwan, M. Ali, K. Iqbal, M. Ansari, W. Salman
This research aims to study the variation in properties of hot-rolled SAE 1006 IF steel sheets during cold rolling to reveal the factors causing the decrease in formability of SPCG steel sheets during deep drawing. Results have shown that pickling does not affect the mechanical properties; however, cold rolling results in an increase in hardness, tensile strength and yield strength. Stress relieve annealing results in coarsening and homogenizing of grains which reduces brittleness and impart ductility. Temper rolling causes an increment in mechanical parameters again, improve surface hardness and flatness. By analyzing the microstructure and comparing it with the HESCO sample, it is revealed that there are still some elongated grains found along with coarse grains after annealing. Soaking time is not sufficient for the growth of homogenized structure, resulting in decreased ductility and formability during deep drawing.
{"title":"Variation in Mechanical Properties of SAE 1006 Interstitial Free (IF) Steel Sheets During Cold Rolling","authors":"A. Chandio, A. Shah, I. A. Channa, S. Abro, Y. Raza, M. Rizwan, M. Ali, K. Iqbal, M. Ansari, W. Salman","doi":"10.24949/NJES.V13I2.623","DOIUrl":"https://doi.org/10.24949/NJES.V13I2.623","url":null,"abstract":"This research aims to study the variation in properties of hot-rolled SAE 1006 IF steel sheets during cold rolling to reveal the factors causing the decrease in formability of SPCG steel sheets during deep drawing. Results have shown that pickling does not affect the mechanical properties; however, cold rolling results in an increase in hardness, tensile strength and yield strength. Stress relieve annealing results in coarsening and homogenizing of grains which reduces brittleness and impart ductility. Temper rolling causes an increment in mechanical parameters again, improve surface hardness and flatness. By analyzing the microstructure and comparing it with the HESCO sample, it is revealed that there are still some elongated grains found along with coarse grains after annealing. Soaking time is not sufficient for the growth of homogenized structure, resulting in decreased ductility and formability during deep drawing.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121472179","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}
Muneeb Qayyum, A. H. Khoja, S. Naqvi, Haider Ejaz, Azra Nawar, Abeera A. Ansari
In the diversification of the world's energy portfolio, microalgae biofuels have gained particular attention as a means of providing carbon-neutral hydrocarbon-based fuels. The progress on this front has been hindered because of expensive and unreliable microalgae cultivation systems, where the preparation of synthetic culture media poses a monetary strain. This study aims to investigate a new microalgae growth media that is readily available and cost-effective. The new microalgae fertilizerbased media (FBM) were designed and compared with Bold Basal media (BBM) in terms of growth parameters, production of lipid and value-added algal by-products (carotenoid and phycobiliprotein). The growth parameters such as cell count and specific growth rate were investigated for FBM and BBM. FBM showed a significant growth rate of 7 million/mL-per day as compared to 2 million/ml per day. A similar growth trend was observed for chlorophyll (a), (b) and carotenes which increased to the values of 5microgram/gram formula weight (µg/gfw), 3 µg/gfw and 2 µg/gfw for FBM. On the other hand, lipid and phycobiliprotein showed a decrease of 18.75 % and 16.66 %, respectively, compared to BBM. Even though some growth parameters are negatively affected by fertilizer-based media, the cost reduction is substantial to allow this drawback to be overlooked. The medium's cost is reduced by a factor of 7 and provides ground for the use of the FBM in the large-scale cultivation of algae for biomass production.
{"title":"Development of Cost-Effective Fertilizer-Based Media for the Microalgae Cultivation Aimed at Effective Biomass Production","authors":"Muneeb Qayyum, A. H. Khoja, S. Naqvi, Haider Ejaz, Azra Nawar, Abeera A. Ansari","doi":"10.24949/NJES.V13I2.628","DOIUrl":"https://doi.org/10.24949/NJES.V13I2.628","url":null,"abstract":"In the diversification of the world's energy portfolio, microalgae biofuels have gained particular attention as a means of providing carbon-neutral hydrocarbon-based fuels. The progress on this front has been hindered because of expensive and unreliable microalgae cultivation systems, where the preparation of synthetic culture media poses a monetary strain. This study aims to investigate a new microalgae growth media that is readily available and cost-effective. The new microalgae fertilizerbased media (FBM) were designed and compared with Bold Basal media (BBM) in terms of growth parameters, production of lipid and value-added algal by-products (carotenoid and phycobiliprotein). The growth parameters such as cell count and specific growth rate were investigated for FBM and BBM. FBM showed a significant growth rate of 7 million/mL-per day as compared to 2 million/ml per day. A similar growth trend was observed for chlorophyll (a), (b) and carotenes which increased to the values of 5microgram/gram formula weight (µg/gfw), 3 µg/gfw and 2 µg/gfw for FBM. On the other hand, lipid and phycobiliprotein showed a decrease of 18.75 % and 16.66 %, respectively, compared to BBM. Even though some growth parameters are negatively affected by fertilizer-based media, the cost reduction is substantial to allow this drawback to be overlooked. The medium's cost is reduced by a factor of 7 and provides ground for the use of the FBM in the large-scale cultivation of algae for biomass production.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114544496","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}
A scientific study has been performed in this research work on the basis of experimental results and ramification to divulge the advancement of second phase particles and its influence on ferrite and austenite phase transformation in less carbon-manganese added steel. Two steels have been engaged in this competition with and without aluminum addition along with nitrogen. To fade out the already present particles, as received steel under investigation was solution heat treated at 1200°C and then both the steel samples were heat treated at 750°C and 810°C for 15, 20, 35, and 70 sec incubation time in the cyanide added liquid bath furnace and were rapidly cooled from elevated temperature at room temperature in ordinary water. Metallography was performed after etching technique in two etchant solutions microstructural features with advanced Olympus optical microscope with polarized light. To further enlarge the important microstructure SEM was used to capture the micrographs. It was concluded that aluminum combine with nitrogen stimulate the fine aluminum nitride (AlN) particles and these particles were the major source to hinder the grain boundary mobility and consequently phase transformation was interrupted in aluminum added steel and it lowers the critical temperatures. Surprisingly there was no such attitude was observed in without aluminum added steel.
{"title":"Nano Particles Effect on Transformation Behavior and Mechanical Properties on Commercial Steel Used for Automobile Parts","authors":"S. Abro, Mohammed N. Alghamdi, H. Moria","doi":"10.24949/NJES.V13I2.622","DOIUrl":"https://doi.org/10.24949/NJES.V13I2.622","url":null,"abstract":"A scientific study has been performed in this research work on the basis of experimental results and ramification to divulge the advancement of second phase particles and its influence on ferrite and austenite phase transformation in less carbon-manganese added steel. Two steels have been engaged in this competition with and without aluminum addition along with nitrogen. To fade out the already present particles, as received steel under investigation was solution heat treated at 1200°C and then both the steel samples were heat treated at 750°C and 810°C for 15, 20, 35, and 70 sec incubation time in the cyanide added liquid bath furnace and were rapidly cooled from elevated temperature at room temperature in ordinary water. Metallography was performed after etching technique in two etchant solutions microstructural features with advanced Olympus optical microscope with polarized light. To further enlarge the important microstructure SEM was used to capture the micrographs. It was concluded that aluminum combine with nitrogen stimulate the fine aluminum nitride (AlN) particles and these particles were the major source to hinder the grain boundary mobility and consequently phase transformation was interrupted in aluminum added steel and it lowers the critical temperatures. Surprisingly there was no such attitude was observed in without aluminum added steel.","PeriodicalId":338631,"journal":{"name":"NUST Journal of Engineering Sciences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115081586","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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