The wear of materials in hydraulic transport pipelines

Bibliography: leaves 60-68.The hydraulic transportation of particulate solids through pipelines results in wear of the pipeline walls. The lifetime of the pipeline is determined by this rate of material loss and is therefore critical to the designer. Due to the small amounts of material lost in in-situ tests, requiring in many cases in excess of 1000 hours testing, an accelerated test procedure is necessary. This work introduces an accelerated method of evaluating materials under simulated pipeline wear conditions. The solids in the slurry and the materials were closely monitored to attain an understanding of their interaction. The wear rate of the materials tested was found to decrease with a decrease in the average rounding of the particles. These changes in particle characteristics occur with time due to comminution within the pump and pipeline. The mechanical properties and wear rates of the materials evaluated were examined to determine whether any relationships existed

Montia linearis Greene

https://thekeep.eiu.edu/herbarium_specimens_byname/10541/thumbnail.jp

PROBABILITY OF TREE SEEDLING ESTABLISHMENT CHANGES ACROSS A FOREST–OLD FIELD EDGE GRADIENT

Forest edges affect many aspects of plant communities, causing changes in microclimate, species composition, and community structure. However, the direct role of edges in regulating forest regeneration is relatively unknown. The pattern of tree establishment across a forest–old field edge was experimentally examined to determine the response of three tree species to the edge gradient. We placed 100 1-m2 plots in a 90 3 90 m grid that began 30 m inside the forest, extended across the edge, and ended at 60 m into the old field. Into each plot, we planted seeds of Acer rubrum, Acer saccharum, and Quercus palustris. Emergence increased with distance into the field for both A. saccharum and Q. palustris. Emergence for A. rubrum increased from forest to field, reaching a maximum near 20 m into the field, and then declined with further distance. Nearly all A. rubrum seedlings died shortly after emergence. Survival of A. saccharum increased with distance into the old field, while survivorship of Q. palustris did not respond to the edge gradient. Establishment probabilities increased with distance into the old field for both A. saccharum and Q. palustris. Growth of Q. palustris and allocation patterns of A. saccharum also varied across the edge gradient. These results suggest that edges have complex, speciesspecific effects on tree establishment and growth that can influence the spatial pattern and species composition of regenerating forests

Rapid redistribution of agricultural land alters avian richness, abundance, and functional diversity

The conversion of natural, or seminatural, habitats to agricultural land and changes in agricultural land use are significant drivers of biodiversity loss. Within the context of land‐sharing versus land‐sparing debates, large‐scale commercial agriculture is known to be detrimental to biodiversity, but the effects of small‐scale subsistence farming on biodiversity are disputed. This poses a problem for sustainable land‐use management in the Global South, where approximately 30% of farmland is small‐scale. Following a rapid land redistribution program in Zimbabwe, we evaluated changes in avian biodiversity by examining richness, abundance, and functional diversity. Rapid land redistribution has, in the near term, resulted in increased avian abundance in newly farmed areas containing miombo woodland and open habitat. Conversion of seminatural ranched land to small‐scale farms had a negative impact on larger‐bodied birds, but species richness increased, and birds in some feeding guilds maintained or increased abundance. We found evidence that land‐use change caused a shift in the functional traits of the communities present. However, functional analyses may not have adequately reflected the trait filtering effect of land redistribution on large species. Whether newly farmed landscapes in Zimbabwe can deliver multiple benefits in terms of food production and habitat for biodiversity in the longer term is an open question. When managing agricultural land transitions, relying on taxonomic measures of diversity, or abundance‐weighted measures of function diversity, may obscure important information. If the value of smallholder‐farmed land for birds is to be maintained or improved, it will be essential to ensure that a wide array of habitat types is retained alongside efforts to reduce hunting and persecution of large bird species

KARAKTERISTIK HABITAT ASUHAN DAN PARAMETER PERTUMBUHAN IKAN HIU DI WILAYAH PENGELOLAAN PERIKANAN NRI 712 (LAUT JAWA), INDONESIA

Keberadaan kelompok ikan hiu di suatu perairan dipengaruhi oleh kondisi oseanografi yang secara langsung dapat mempengaruhi penyebaran ikan, migrasi, agregrasi, pemijahan, persediaan makanan, tingkah laku ikan dan variabilitas hasil tangkapannya. Paper ini bertujuan untuk mengidentifikasi daerah asuhan hiu dan mengetahui karakteristik habitatnya di wilayah perairan Laut Jawa, dan sekaligus untuk mendukung program Kementerian Kelautan dan Peikanan dalam pengembangan Marine Protected Area. Metode yang digunakan adalah enumerasi dan wawancara. Hasil penelitian menunjukan bahwa habitat asuhan ikan hiu terutama dari jenis Sphryna lewini, Carcharhinus dussumieri, Carcharhinus falciformis, Carcharhinus sorrah, dan Rhizoprionodon oligolinx tersebar pada wilayah yang cukup luas di WPP 712 Laut Jawa dengan cakupan koordinat 3o Lintang Selatan (LS) - 6o LS dan 108o Bujur Timur (BT) - 115o BT dengan rentang kedalaman sekitar 21,60 m hingga 77,85 m, pada suhu rata-rata berkisar 16,66oC-30,35oC dan salinitas rata-rata pada kisaran 25,13 psu-34,56 psu.The existence of shark groups is influenced by oceanographic conditions which can directly affect fish distribution, migration, aggregation, spawning, food supply, fish behavior and variability in their catch. This paper aims to predict nursery ground of shark and determine the characteristics of their habitat in the Java Sea waters, and at the same time to support the Ministry of Marine Affairs and Fisheries program in developing Marine Protected Areas. The methods used were enumeration and interviews. The results showed that the habitat for sharks, especially those of Sphryna lewini, Carcharhinus dussumieri, Carcharhinus falciformis, Carcharhinus sorrah, and Rhizoprionodon oligolinx, is spread over a fairly large area in WPP 712 Java Sea or in the coordinates of -3o to -6o LS and 108o sd. 115o BT with a depth range of about 21.60 m to 77.85 m, at an average temperature ranging from 16.66oC-30.35oC and an average salinity of 25.13psu-34.56psu

Seasonal variation in daily patterns of social contacts in the European badger Meles meles

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Social interactions among hosts influence the persistence and spread of infectious pathogens. Daily 20 and seasonal variation in the frequency and type of social interactions will play an important role in 21 disease epidemiology, and alongside other factors may have an influence on wider disease dynamics 22 by causing seasonal forcing of infection, especially if the seasonal variation experienced by a 23 population is considerable. We explored temporal variation in within-group contacts in a high-24 density population of European badgers Meles meles naturally-infected with bovine tuberculosis. 25 Summer contacts were more likely and of longer duration during the daytime, while the frequency 26 and duration of winter contacts did not differ between day and night. In spring and autumn within-27 group contacts peaked at dawn and dusk, corresponding with when they were of shortest duration 28 with reduced potential for aerosol transmission of pathogens. Summer and winter could be critical 29 for bovine tuberculosis transmission in badgers, due to the high frequency and duration of contacts 30 during resting periods, and we discuss the links between this result and empirical data. This study 31 reveals clear seasonality in daily patterns of contact frequency and duration in species living in stable 32 social groups, suggesting that changes in social contacts could drive seasonal forcing of infection in 33 wildlife populations even when the number of individuals interacting remains similar.MJS is funded by NERC grant NE/M004546/1 awarded to RAM, DPC, DJH and MB, with RJD and the 386 APHA team at Woodchester Park, UK as project partners. Data were collected for NW’s PhD, funded 387 by Defra. We thank Jared Wilson-Aggarwal and two anonymous reviewers for useful comments and 388 Keith Silk for providing the photograph for Figure 1