April 2020最新文献

{"title":"Papermaking properties of bacterial nanocellulose produced from mother of vinegar, a waste product after classical vinegar production","authors":"G. Lavrič, Daša Medvešček, M. Skočaj","doi":"10.32964/tj19.4.197","DOIUrl":"https://doi.org/10.32964/tj19.4.197","url":null,"abstract":"Bacterial nanocellulose (BNC) has gained a lot of attention in recent years due to its nano-size-derived properties. Although it is essentially chemically similar to plant-derived cellulose, it has smaller size and is enriched in free hydroxyl groups, which greatly improve mechanical properties of reinforced paper. However, although BNC has some unique features, it comes at a high price. In this paper, we introduce a new solution for BNC production. We have isolated bacterial nanocellulose directly from agro-industrial waste—mother of vinegar—and used it in the production of paper sheets. We show here that paper sheets made with the addition of only 10% bacte-rial nanocellulose from mother of vinegar substantially improved basic mechanical as well as printing properties of paper.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115769119","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}

{"title":"How to use total dissolved solids measurements to evaluate the performance of diffuser washers—A mill study","authors":"Riku Kopra, Anna Personen, Jari Kayhko, O. Dahl","doi":"10.32964/tj19.4.187","DOIUrl":"https://doi.org/10.32964/tj19.4.187","url":null,"abstract":"Various types of pulp washing equipment are available. Each washing device has a unique mechani-cal construction, and the washing principle is often a combination of dilution, thickening, and displacement washing. In this work, the performance of the pressure diffuser washer is studied.\u0000In stepwise trials, the effect of the feed and discharge consistencies on the performance of the diffuser was stud-ied. The effect of the downward velocity of the screen on the pressure diffuser’s washing efficiency was also stud-ied. The measurement of total dissolved solids (TDS) by a process refractometer was used as a wash loss measure-ment unit and the refractometer’s results were used in the calculations of standardized Nordén efficiency (E10) values. The chemical oxygen demand (COD) and conductivity values were also measured and their results com-pared to the TDS results.\u0000The results indicated that feed consistency has a significant effect on the performance and effectiveness of the diffuser washers in the mill. It can also be stated that when the downward velocity of the screen is adjusted to too high a level, the washing efficiency of the pressure diffuser decreases. As a conclusion from the mill tests, it can be stated that even small process parameter changes can provide enhanced diffuser washing at the beginning of the washing line, which has a direct effect on the performance of post-oxygen washing.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125762327","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}

{"title":"Creasing severity and reverse-side cracking","authors":"J. Panek, Swan D. Smith, D. Coffin","doi":"10.32964/tj19.4.219","DOIUrl":"https://doi.org/10.32964/tj19.4.219","url":null,"abstract":"Crease cracking can be detrimental to the functionality and appearance of paperboard-based pack-aging. The effect of creasing severity on the degree of reverse-side crease cracking (bead-side of the crease) of paperboard was investigated. Samples were creased with a range of rule and channel geometries, and the cracking degree was quantified as the percent of cracked length relative to the total length of the crease. The cracking degree was typically below 5% at low crease penetration depths, but was exponentially higher beyond a critical penetration depth. A rule and channel combination with a wider clearance shifted the critical depth to larger values. \u0000 The creasing severity parameter, termed the creasing draw, converged the cracking degree data from different rule and channel combinations to a single curve. The creasing draw was derived from the same analytical expres-sions as the transverse shear strain and quantifies the length of paper that is drawn into the channel during creasing. The critical draw is defined as the draw at which cracking becomes greater than 5%, which corresponds with the point at which cracking becomes exponential. The critical draw is a material/system parameter that defines the level below which cracking is minimal.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"25 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114038659","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}

{"title":"Fruit canopy position and harvest date influence on colour and quality of Imperial mandarin (Citrus reticulata Blanco)","authors":"P. Adhikari, Z. Singh, V. Y. Tokala, Poe Nandar Kyaw, Bronwyn B. Walsh","doi":"10.21475/ajcs.20.14.04.p2304","DOIUrl":"https://doi.org/10.21475/ajcs.20.14.04.p2304","url":null,"abstract":"Rind colour and taste are important factors influencing consumer acceptance of mandarins (Citrus reticulata Blanco) fruit. In this experiment, the influence of fruit canopy position and harvest date on the fruit rind colour and other quality parameters of Imperial mandarins was investigated. The mandarin fruit were harvested from four different positions in the tree canopy i.e., upper-inner, upper-outer, lower-inner and lower-outer and at three different harvest dates (H1 (five days before commercial harvest date); H2 (commercial harvest date) and H3 (five days after commercial harvest date). The experiment was conducted using a two factors (fruit position and harvest time) factorial randomised block design with four replicates and fifteen fruit per replicate. Rind colour and the quality of Imperial mandarins were significantly affected by the fruit position in the tree canopy, with the fruit harvested from the upper canopy having better rind colour and higher levels of organic acids and sugars compared to other positions. The late harvested (H3) mandarins exhibited the best fruit colour. In conclusion, the Imperial mandarin fruit had better fruit colour as well as quality when harvested from the upper canopy and by delaying the fruit harvest date by five days from the original commercial harvest date.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115048491","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}

{"title":"Water and nitrogen water use efficiency in forage palm irrigated with salt water in the Neossolo","authors":"P. F. D. Silva, R. M. B. Matos, J. D. Neto, V. Borges, Thiago Galvão Sobrinho, Semako Ibrahim Bonou, Carlos Alberto Vieira de Azevedo, V. L. Lima, A. P. M. Junior","doi":"10.21475/ajcs.20.14.04.p2404","DOIUrl":"https://doi.org/10.21475/ajcs.20.14.04.p2404","url":null,"abstract":"The objectives were to analyze the water and nitrogen use efficiency by forage palm in different irrigation depths with saline water and nitrogen fertilization levels in the Brazilian semi-arid region. The experiment was conducted under field condition during one year of cultivation (360 days). The experimental design was a complete randomized block and 5 x 5 factorial scheme with five irrigation depths (125, 100, 75, and 25% of ET0) and five levels of nitrogen fertilization (0, 150, 300, 450 and 600 kg ha-1 of N) and three replicates. Irrigation and acceptable nitrogen fertilization resulted in a good water and fertilization management. Water and nitrogen use efficiency of forage palm were higher, when water depths and the nitrogen levels supplied to the soil were increased. The 125% ET0 depth showed a higher efficiency of water and nitrogen use in the forage palm during 360 days of study. In conditions of low nitrogen supply, the efficiency of nitrogen use is directly and indirectly associated with the fresh mass yield; while under high supply, the efficiency of the use of nitrogen is more effective. The use of irrigation and nitrogen fertilization in the semi-arid region is recommended to obtain higher productivity of water and nitrogen from the forage palm.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133069998","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}

{"title":"A Study of Software Development Cost Estimation Techniques and Models","authors":"Junaid Rashid, M. W. Nisar, Toqeer Mahmood, A. Rehman, Yasser Arafat Syed","doi":"10.22581/10.22581/muet1982.2002.18","DOIUrl":"https://doi.org/10.22581/10.22581/muet1982.2002.18","url":null,"abstract":"SDCE (Software Development Cost Estimation) has always been an interesting and budding field in Software Engineering. This study supports the SDCE by exploring its techniques and models and collecting them in one place. This contribution in the literature will assist future researchers to get maximum knowledge about SDCE techniques and models from one paper and to save their time. In this paper, we review numerous software development effort and cost estimation models and techniques, which are divided into different categories. These categories are parametric models, expertise-based techniques, learning-oriented techniques, dynamicsbased models, regression-based techniques, fuzzy logic-based methods, size-based estimation models, and composite techniques. Some other techniques which directly do not lie in any specific category are also briefly explained. We have concluded that no single technique is best for all situations; rather they are applicable in different nature of projects. All techniques have their own pros and cons and they are challenged by the rapidly changing software industry. Since no single technique gives a hundred percent accuracy, that is why one technique and model should not be preferred over all others. We recommend a hybrid approach for SDCE because in this way the limitations of one model and technique are complemented by the merits of the other model/technique. We also recommend a model calibration to obtain accurate results because if a model was developed in a different environment, we cannot expect reliable estimates from it in a completely new environment.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"11 26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124240686","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}

{"title":"An SVC controller for Power Quality Improvement of a Heavily Loaded Grid","authors":"Faheem Ali, M. N. Arbab, G. Ahmed, M. Ashraf, M. Sarim","doi":"10.22581/10.22581/muet1982.2002.03","DOIUrl":"https://doi.org/10.22581/10.22581/muet1982.2002.03","url":null,"abstract":"Pakistan is faced with energy crises from the last two decades. Generation cannot balance the load demands of the electricity consumers. Power delivery systems are generally old-fashioned and overloaded. They are unable to provide consistent and uninterrupted supply to commercial, industrial, and domestic loads. Generally speaking, the Power Systems consist of loads that are inductive and resistive in nature. Heavy machinery, induction motors, and arc furnaces are heavily inductive in nature. Inductive loads when operated in a weak power system results in lagging VARs (Volt Ampere Reactive) and poor voltage regulation, which must be balanced by the same number of leading VARs in order to ensure unity power factor and thus helps in improving the voltage profile. At times the reactive VARs injected may not be sufficient to balance the VARs requires by the system, but still the power factor is improved up to some extent. In hot and humid climatic conditions, air-cooling system and chillers greatly burdens the grids. Such loads require excessive reactive VARs, and if not offered with ample reactive power, causes severe voltage drops in distribution system. To manage low voltages and power-factor, household users use automatic voltage regulators while industries connect capacitor banks. Voltage regulators control output voltage within the required limits at the expense of excessive line current from transformer, which may overburden it. Moreover, with each operation of tap changer, current rises which further intensifies line losses. Static capacitors provide stable voltage but repeated variations in load demands reliable and vigorous voltage regulation. This investigation aims to come up with a power quality improvement scheme which would deliver instantaneous control of power (reactive) with SVC (Static VAR Compensator) thus overcoming the shortcomings of step-wise banks of capacitors and or voltage regulators. Simulation work is carried out in MATLAB/SIMULINK and the results are compliance with IEEE Standards for SVCs. The device can offer steady state as well as dynamic VAR compensation under changing load conditions. Result showed considerable improvement both in terms of response time and power factor. Switching time has been improved to less than 1/10th fraction of a second which in previous simulations was 0.7 seconds approximately. Initial power factor without disturbance and without compensation was recorded to be 0.6 lagging, which after compensation was improved to 0.95 lagging. Similarly, in presence of disturbance without compensation the power factor fluctuated between 0.55 and 0.9 lagging, which after compensation was improved to 0.95 lagging and above throughout the course of operation.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131190432","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}

{"title":"Dinosaur rustling in the Old West","authors":"","doi":"10.1144/geosci2020-16-19","DOIUrl":"https://doi.org/10.1144/geosci2020-16-19","url":null,"abstract":"","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132753860","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}

{"title":"Excavating Jurassic Giants","authors":"","doi":"10.1144/geosci2020-075","DOIUrl":"https://doi.org/10.1144/geosci2020-075","url":null,"abstract":"","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117075408","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}

{"title":"Coral Community: Preliminary Biodiversity Survey of Churna Island, Northern Arabian Sea","authors":"S. Amjad, N. Khan, S. Ishaq","doi":"10.22581/10.22581/muet1982.2002.15","DOIUrl":"https://doi.org/10.22581/10.22581/muet1982.2002.15","url":null,"abstract":"Biodiversity survey between Cape Monze and Churna Island was carried out for the assessment of coral assemblages in the area. During the present study, diving surveys were conducted to document the living corals that included deep sea coral, Coelenterates, Bryozoans, Gorgonia (Sea Fan), Scleractinian, (Stony Corals) Cnidaria (Hydroids), Porites (Small Polyp Stony), Pocilopora (Cauliflower Corals), Acropora (Hard Corals), sea urchins, sea anemones, coral fish spp, sea slugs, stone fish and bivalves were observed and documented. To have a better understanding of the distribution pattern “Shannon Weiner Biodiversity Index” for species diversity “H” (0.845-1.176) and evenness “J” (0.962-0.937) were calculated, the values indicate that the coral species were evenly distributed and did not show any significant variation in the area. Budding coral communities were observed at the sedimentary rock of Churna in patches, and showed a random distribution behavior all along the surveyed area. Random, scattered and aggregate distribution patterns of corals may be due to the wave beaten physical environment of Churna Island that do not allow sustainable growth of coral communities. Moreover, the high energy waves and water currents destablize and erode the sedimentary substrate on which corals grow. The corals are therefore unable to establish themselves to form a natural reef due to loss of natural living and non-living substrate. The ecology of Churna Island also under the influence of nearby coastal industries, and the Hub River influx causing floods in the SW monsoon period that may destablize rubble and increase the seawater turbidity level. These environmental factors contributing to the deterioration of present day corals, and larval settlement. It may be concluded that biological resources are renewable and can even increase with proper management techniques. Breakwater wall and artificial substrate must be encouraged to further facilitate the growth and development of Corals in the area.","PeriodicalId":265427,"journal":{"name":"April 2020","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127310519","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}