检索结果-南通市图书馆

Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2016年第1期10卷 30-43页

作者： Jie HAN harihar Shiwakoti Department of Civil Environmental and Architectural Engineering the University of Kansas Lawrence KS 66044 USA Virginia Department of Transportation 1401 E. Broad St. Richmond VA 23219 USA

Existing test methods to determine moisture sensitivity in hot-mix asphalt （HMA） mixtures are time consuming and inconsistent. This research focused on wheel tracking devices to evaluate moisture sensitivity. The Asphalt Pavement Analyzer （APA） and the Hamburg Wheel Tracking Device （HWTD） were used for this research. Compacted cylindrical samples were fabricated using a Superpave Gyratory compactor. This study selected two most commonly used mixtures, SM-12.5A with PG 64-22 binder in overlay projects and SM-19A mixtures with PG 64-22 binder for major modification projects at Kansas Department of Transportation. Test results show that APA tests could induce stripping in most samples without any anti-stripping agent, which could be identified visually. However, APA results did not indicate any stripping inflection point while the HWTD results showed stripping inflection points, which are important to identify stripping potential of mixtures. The APA results show that wet tests are severe at lower temperatures. The HWTD results show improvement in the performance using anti-stripping agents at later stage. The HWTD test is more effective as a rapid test method in case of determining moisture sensitivity. Laboratory results from this study should be verified and correlated with field performance.

关键词： hot-mix asphalt moisture sensitivity rutting wheel tracking test

On the spatio-temporal variation in b-value after 25 April 2015 Gorkha,Nepal earthquake

在线全文

学校读者我要写书评

暂无评论

Geodesy and Geodynamics 2022年第5期13卷 525-533页

作者： Ram Krishna Tiwari harihar Paudyal Daya Shanker Central Department of Physics Tribhuvan UniversityKirtipurKathmanduNepal Birendra Multiple Campus Tribhuvan UniversityBharatpurChitwanNepal Department of Earthquake Engineering Indian Institute of Technology RoorkeeRoorkeeUttarakhandIndia

In the present study,the spatial-temporal distribution of b-value along the five faults area(the Judi fault,Thaple fault,Kathmandu fault,Motihari-Gauri Shanker fault,and Motihari-Everest fault)was investigated after the Gorkha earthquake(M7.8).The earthquake catalog of 10,500 events was prepared by compiling the published *** study area is bounded in the central Himalaya from 26.5°to 29°in latitude direction and 84°to 87°in longitude *** frequency magnitude distribution shows the variation of the b-value along with fault areas from 0.45 to 0.69,indicating a common characteristic of aftershock *** particular,the Judi fault area,Thaple fault area,and Motihari-Everest fault area are characterized by the low b-values of 0.45±0.02,0.48±0.02,and 0.55±0.04,*** regions could be the source region for future *** low b-value observed for fault areas are also consistent with the thrust faulting pattern in the region as indicated by the focal mechanism of mainshock and major *** temporal variation of b-value shows inevitable fluctuations during25 April to 12 May *** the area selected,the Motihari-Everest fault area is in critical strain(mechanically locked)conditions,as indicated by the stepwise energy release pattern.

关键词： Frequency-magnitude distribution Time series analysis Thrust fault Stress Central Himalaya

Probabilistic seismic hazard analysis in Nepal

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2013年第4期12卷 577-586页

作者： thapa Dilli Ram Wang Guoxin State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology

The seismic ground motion hazard for Nepal has been estimated using a probabilistic approach. A catalogue of earthquakes has been compiled for Nepal and the surrounding region （latitude 26% N and 31.7% N and longitude 79° E and 90° E） from 1255 to 2011. The distribution of catalogued earthquakes, together with available geological and tectonic information were used to delineate twenty-three seismic source seismic source information and probabilistic earthquake hazard prediction relationship, peak ground accelerations （PGAs） have zones in Nepal and the surrounding region. By using the parameters in conjunction with a selected ground motion been calculated at bedrock level with 63%, 10%, and 2% probability of exceedance in 50 years. The estimated PGA values are in the range of 0.07-0.16 g, 0.21 0.62 g, and 0.38-1.1 g for 63%, 10%, and 2% probability of exceedance in 50 years, respectively. The resulting ground motion maps show different characteristics of PGA distribution, i.e., high hazard in the far-western and eastern sections, and low hazard in southern Nepal. The quantified PGA values at bedrock level provide information for microzonation studies in different parts of the country.

关键词： seismic hazard assessment peak ground acceleration earthquake Nepal Himalaya

Understanding human-leopard conflict in the ‘Mid-hill’ region of western Nepal

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第12期20卷 3464-3475页

作者： LAMICHHANE Saroj thapa Arjun thapa Mahendra Singh PANTHI Saroj GIORDANO Anthony J School of Forestry and Natural Resources Management Institute of ForestryKirtipur 44613Nepal Institute of Fundamental Research and Studies(InFeRS) Baniyatar 44608Nepal Institute of Zoology Chinese Academy of SciencesBeijing 100101China Institute of Forestry Office of DeanKirtipur 44613Nepal Ministry of Industry TourismForest and EnvironmentKaski 33700Nepal SPECIES-The Society for the Preservation of Endangered Carnivores and their International Ecology Study VenturaCA 93006USA

Livestock rearing and agriculture are the main sources of community-based livelihoods in western *** the rural mid-hills region of Gandaki Province,leopards are the top predator and frequently depredate livestock and attack *** patterns of human-leopard conflicts(HLC) in Nepal are poorly known at the provincial and national scales,which are essential to formulating effective conflict mitigation strategies and implementing them in the *** study aims to analyze the spatiotemporal pattern of HLC by applying Maxent modeling to covariates relating to known and registered conflict cases(n=842) collected from Nepalese government *** found that cases of HLC have been increasing significantly over the past five *** also concluded that mid-elevation,south-facing slopes were more susceptible to HLC,but that mean annual temperature was by far the most important predictor of HLC;overall livestock density and proximity to roads were also important,but secondarily *** we found the increase in human fatalities to 2.16/year was significant(p0.05).However,we also found an increasing trend in livestock depredation rates for this same five-year period(p<0.05),which averaged 159.6 head/year among incidents *** also found that winter was the main season when depredations occurred,and that goats were the most depredated of all livestock.A total US $86,892.25($17,378.45/year) of economic losses were incurred by communities during this time,with 78.57% of the total value reimbursed as compensatory relief through the government’s relief *** recommend that the use of predator-proof livestock corrals,greater awareness in local communities about wildlife behavior,better animal husbandry and security practices,and a more efficient compensation program,can improve coexistence between leopard populations and human communities in western Nepal.

关键词： Coexistence Compensation Economic loss Human-wildlife conflict Livestock depredation Maximum entropy Problem animals Sustainable livelihood

Factors affecting technical efficiency of small-scale apple farms in Balochistan Plateau, Pakistan

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2017年第4期14卷 782-794页

作者： Ghulam MURTAZA Gopal Bahadur thapa Disaster Management and Development Studies University of Balochistan School of Environment Resources and Development Asian Institute of Technology

In Balochistan, Agriculture is dominated by small-scale farmers and the apple production sector is confronted with the chronic constraint of low output per unit of input. Although some agricultural policies have been implemented in this province, studies on effectiveness and impacts of such policies over apple production and farmers' performance are still limited. This study is an effort to bridge the research gap on this potential crop in the plateau by investigating technical and scale efficiency of 181 officially designated small-scale apple farmers in mountainous district Mastung in Balochistan; then explored factors that underlie differences in production inefficiency. A two-stage input-oriented Data Envelopment Analysis(DEA) methodology was employed to evaluate technical and scale efficiency followed by truncated bootstrapped regression framework to analyze the correlative determinants to efficiency. Average technical and scale efficiencies of larger landholders were higher than medium and small landholders. Analysis indicated that there is still ample scope for inefficient sample farmers to reduce the input use by 33% without compromising the given yield level. Maximum contributions to the total input savings were from the use of urea, farm yard manure(FYM) and labor-use. Farmer's experience, farm ownership, irrigation constraints, and farmer's access to trainings, credit and extension services significantly affected apple farmers' technical efficiency. Based on the findings of this study, strategies are suggested to enhancing efficiencies by farmers' capacity development through effective extension services and trainings and provision of adequate credit.

关键词： Small-scale apple farmers Technical efficiency Data envelopment analysis (DEA) Bootstrap Efficiency-improving resources Balochistan Plateau

Gorkha earthquake (MW7.8) and aftershock sequence: A fractal approach

在线全文

学校读者我要写书评

暂无评论

Earthquake Science 2022年第3期35卷 193-204页

作者： Ram Krishna Tiwari harihar Paudyal Central Department of Physics Tribhuvan UniversityKirtipurKathmandu 44618Nepal Birendra Multiple Campus Tribhuvan UniversityBharatpurChitwan 44200Nepal

On April 25, 2015, Nepal was struck by the MW7.8 Gorkha earthquake followed by an intense aftershock sequence. It was one of the most destructive earthquakes in the Himalayan arc, causing more than 8900 fatalities. In this study, we analyzed the dataset (429 events, magnitude of completeness (Mc) ≥ 4.2 local magnitude) of the first 45 days after the Gorkha earthquake to estimate the seismicity parameters b-value, D-value, and p-value. We used the maximum likelihood method to estimate the b-value and Omori-Utsu parameters, whereas the correlation integral method was applied to estimate the fractal dimension (D-value). The analysis was carried out using running and sliding window techniques. The lowest b-value (0.57 ± 0.04) and the highest D-value (1.65 ± 0.02) were computed at the time of the Gorkha earthquake, after which the b-value significantly increased to a maximum of 1.57. It again dropped to 0.93 at the time of the major aftershock on May 12, 2015. The D-value showed an initial quick drop and then decreased in a wavy pattern until the end of the study period, indicating the clustering and scattering of earthquakes in a fault region. The b-value contour map identified the eastern part of the study area as a high stress region (b = ~0.8), implying that the stress shifted to that region. The D-value contour map reveals that the seismogenic structure shifted from linear to planar in the region. The rate of aftershock decay (p = 0.86 ± 0.04) for a short period reflects that the level of stress decreased rapidly. This study helps to understand the level of stress and seismicity pattern of a region, which could be useful for aftershock studies.

关键词： Omori-Utsu law correlation integral fractal dimension b-value central Himalaya

Optimization of pelleting parameters for producing composite pellets using agricultural and agro-processing wastes by Taguchi-Grey relational analysis

在线全文

学校读者我要写书评

暂无评论

Carbon Resources Conversion 2020年第1期3卷 104-111页

作者： Shyam thapa Robert Engelken Natural Sciences Aims Community CollegeGreeleyCO 80634USA College of Agriculture Engineering and TechnologyArkansas State UniversityState UniversityJonesboroAR 72467USA

Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are *** biomass especially crop residues’potential to green energy development has been *** conditions as process variable was made a centerpiece of investigation in the present study since several parameters in the feedstock mixture come into interplay during ***,binders,blending ratio,particle size,and principle feedstock material were the parameters of our interest in finding their effect on physical and thermochemical *** is also an endeavor to investigate low cost binder options in producing composite pellets of high quality.A Taguchi L9 orthogonal array experimental design was employed and Taguchi based Grey relational analysis was performed to determine the best combinatorial optimization of factor levels settings for producing best *** optimal parameter level settings for pelletization was determined to be 3.18 mm wheat feedstock material blended with pine shavings at 60/40 *** analysis of variance(ANOVA)was conducted to identify the contribution of each *** magnitude of the significant impacts of parameters on performance characteristics were in the order of binder>blend ratio>grind>feedstock *** also showed that the physico-chemical characteristics of the pellets were concomitant with the proportion of ingredients or recipes in a blend.

关键词： Agricultural waste Crop residues Optimization Pelletization Grey relational analysis Taguchi analysis Agricultural waste management Resource conversions and conservation Waste conversion into resource

Prospecting microbial biofilms as climate smart strategies for improving plant and soil health: A review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2023年第1期33卷 129-152页

作者： Kulandaivelu VELMOUROUGANE Shobit thapa Radha PRASANNA Division of Crop Production Indian Council of Agricultural Research-Central Institute for Cotton Research(CICR)Nagpur 440010India Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms KushmaurMau Nath Bhanjan 275103India Division of Microbiology Indian Council of Agricultural Research-Indian Agricultural Research InstituteNew Delhi 110012India

Microbes and their products play key roles in complementing chemical fertilizers and plant protection chemicals by eliciting defence mechanisms in crop plants,thereby providing immunity and resistance against diverse *** the different environmental technologies used to mitigate climate change,several microbiological interventions are promising,among which biofilms,both naturally-existing and laboratory-developed,and their application have gained momentum *** biofilms are aggregations of microbial cells in a self-generated polymeric matrix,which are produced by several genera of bacteria,yeasts,cyanobacteria,and fungi as a mode of reproductive fitness,thereby advantageous in successful proliferation,even in extreme *** propensity of microbial biofilms to grow in diverse niches and adapt to biotic and abiotic stresses illustrates their immense potential as biofertilizers and disease suppression options in various crops across diverse *** the inhospitable habitats of deserts and denudated land,biofilms play an important role in preventing soil erosion and sustaining vegetation,microflora,and *** represent a mode of growth for several microbes with plant growth-promoting and biocontrol potential,which are important in seed establishment and the facilitation of exchanging nutrients and metabolites from the *** this review,we discuss the prospects of microbial biofilms as a green option in agriculture in general and,more specifically,their potential in mitigating climate change.

关键词： biocontrol bioremediation climate change environmental stress nutrient sequestration plant growth promotion

Density and carrying capacity in the forgotten tigerland:Tigers in the understudied Nepalese Churia

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2017年第3期12卷 211-227页

作者： Kanchan thapa Marcella J.KELLY Department of Fish and Wildlife Conservation Virginia TechBlacksburgVirginiaUSA Conservation Science Unit WWF NepalBaluwatarKathmanduNepal

While there are numerous wildlife ecology studies in lowland areas of Nepal,there are no in-depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai *** investigated tiger,leopard and prey densities across this understudied *** camera trapping survey covered 536 km2 of Churia and surrounding areas within Chitwan National Park(CNP).We used 161 trapping locations and accumulated 2097 trap-nights in a 60-day survey period during the winter season of *** addition,we walked 136 km over 81 different line transects using distance sampling to estimate prey *** photographed 31 individual tigers,28 individual leopards and 25 other mammalian *** capture-recapture methods resulted in lower density estimates for tigers,ranging from 2.3 to 2.9 tigers per 100 km2,than for leopards,which ranged from 3.3 to 5.1 leopards per 100 *** addition,leopard densities were higher in the core of the Churia compared to surrounding *** estimated 62.7 prey animals per 100 km2 with forest ungulate prey(sambar,chital,barking deer and wild pig),accounting for 47%of the *** on prey availability,Churia habitat within CNP could potentially support 5.86 tigers per 100 km2 but our density estimates were lower,perhaps indicating that the tiger population is below carrying *** results demonstrate that Churia habitat should not be ignored in conservation initiatives,but rather management efforts should focus on reducing human disturbance to support higher predator numbers.

关键词： camera trapping carrying capacity churia habitat Panthera tigris tigris spatially explicit capture recapture