bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal Distribution of Dissolved Trace Metal in the Coastal Waters of Southwestern Bay Of Bengal, India
Authors: Padhi R.K. , Biswas S. , Mohanty A.K. , Prabhu R.K. , Satpathy K.K. , Nayak L.
Published: January 2013

The objective of the present study was to characterize the concentrations of selected dissolved trace metals in the coastal waters (500 m from shore) of Kalpakkam, Tamil Nadu, India. The order of dissolved concentration of these metals was found to be as follows: Co (cobalt) < Cd (cadmium) < Cr (chromium) < Mn (manganese) < Cu (copper) < Ni (nickel) < Pb (lead) < Zn (zinc). The levels of these trace metals were found to be relatively low as compared to the reported values for other Indian coastal waters, which indicates negligible pollution at this location. Cadmium was the only metal found to increase its concentration during the monsoon period, suggesting its allochthonous input. Factor analysis indicated that chromium, nickel, zinc, cobalt, copper, manganese, and lead were of common origin, and external inputs through land runoff had nominal or little impact, typifying in‐situ regeneration and remineralization linkage with their temporal variation. However, levels of zinc, cobalt, and copper remained relatively high during the summer period, and abrupt increases in their concentration during December (monsoon season) may be due to their dual (autochthonous as well as allochthonous) input.
Intragranular ferrite morphologies in medium carbon vanadium-microalloyed steel
Authors: Fadel A. , Glisic D. , Radovic N. , Drobnjak D.
Published: January 2013

The aim of this work was to determine TTT diagram of medium carbon V-N
micro-alloyed steel with emphasis on the development of intragranular ferrite
morphologies. The isothermal treatment was carried out at 350, 400, 450, 500,
550 and 600?C. These treatments were interrupted at different times in order
to analyze the evolution of the microstructure. Metallographic evaluation was
done using optical and scanning electron microscopy (SEM). The results show
that at high temperatures (? 500?C) polygonal intragranulary nucleated
ferrite idiomorphs, combined with grain boundary ferrite and pearlite were
produced and followed by an incomplete transformation phenomenon. At
intermediate temperatures (450, 500?C) an interloced acicular ferrite (AF)
microstructure is produced, and at low temperatures (400, 350?C) the sheave
of parallel acicular ferrite plates, similar to bainitic sheaves but
intragranularly nucleated were observed. In addition to sheaf type acicular
ferrite, the grain boundary nucleated bainitic sheaves are observed.
Rhodium catalysts build into the structure of a silicate support in the hydroformylation of alkenes
Authors: Borrmann Thomas , McFarlane Andrew , Ritter Uwe , Johnston James
Published: January 2013

Rhodium is build into a nano-structured calcium silicate during the synthesis of the silicate. Thereby, it was desired to create a robust heterogeneous catalyst, which does not suffer from catalyst leaching like rhodium impregnated on a pre-formed silicate. While this was achieved, the silicate structure was adversely affected by the incorporation of rhodium — the surface area and pore volume of the material were found to be comparatively low. Alcohol and acid washing were tested to address this issue. The alcohol treatment proved detrimental as catalytic material was leached from the silicate. The acid washed rhodium containing calcium silicate was quite active in the hydroformylation of alkenes and did not suffer loss of catalyst into the product phase. Acid treated rhodium containing silicates were more active than their untreated counterparts but less selective due to access to the rhodium centers being opened.
Characteristics of polyurethane-based sustained release membranes for drug delivery
Authors: Mândru Mihaela , Ciobanu Constantin , Vlad Stelian , Butnaru Maria , Lebrun Laurent , Popa Marcel
Published: January 2013

This paper is focused on the preparation and physicochemical characterization of two poly(ester ether urethane)s with rifampicin in their matrix and different molar concentrations of urethane groups. The polyurethanes with rifampicin were processed as asymmetrical microporous membranes by a phase inversion method and characterized by attenuated total reflection — Fourier transform infrared (ATR-FTIR) spectroscopy and differential scanning calorimetry (DSC). The influence of the surface morphology in the release of drug compounds was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle, and water uptake. The release of rifampicin depends on the molar concentration of urethane groups and also on the surface morphology of the polyurethane membranes. The antibacterial activity was evaluated with S. Epidermidis RP 62 A and P. Aeruginosa ATCC 1544. Finally, the biocompatibility of the polyurethane membranes was studied with human dermal fibroblasts (HDF) to evaluate the potential biomedical applications.
Selection of mineralised methods to analyse different types of matrices. Applying the Box-Cox transformation to chemometrics study the coexistence of heavy metals in natural samples
Authors: Sajdak Marcin , Pieszko Celina
Published: January 2013

Chemometric methods are mostly used to optimise technological processes and analytical procedures. Applying chemometric methods in environmental tests may reveal relationships among chemical elements in biomes. Cluster analysis and principal component analysis (PCA) are very helpful for detecting relationships among studied parameters. However, large amounts of data may have a negative effect on this analysis and can lead to misinterpretation of the results. This situation was observed when the samples, taken from several places in the Silesian Province, were used to test the relationship between heavy metals contained in various environmental matrices. Samples were collected from a small area and were characterised by a single biome (pine forest) because direct interpretation of PCA and CA was insufficient to correctly describe such data. The solution to this problem was the use of the Box-Cox transformation, which is a rapid method to normalise input data.

The application of chemometric tools enabled the relationships between sampling sites (industrialised and non-industrialised) to be examined and was very helpful in illustrating the relationship between the methodologies of plant preparation samples. Furthermore, the results may indicate the need for further data analysis. The tools described in this paper can be useful for choosing the optimal mineralisation method according to the type of test matrix.
Principal component analysis in interpretation of the results of HPLC-ELC, HPLC-DAD and essential elemental contents obtained for medicinal plant extracts
Authors: Konieczynski Pawel
Published: January 2013

Principal component analysis (PCA) was applied to compare its usefulness with cluster analysis (CA), and factorial k-means analysis (fkm), for evaluating the results obtained using HPLC-DAD, HPLC-ELC and spectroscopic techniques (AAS and UV/VIS spectrometry for determining content of N, P, Fe and Cu) in aqueous extracts of seven medicinal plants. These represented the following plant species that are rich in flavonoids: Betula verrucosa Ehrh., Equisetum arvense L., Polygonum aviculare L., Viola tricolor L., Crataegus oxyacantha L., Sambucus nigra L. and Helichrysum arenarium (L.) Moench. The databases analyzed comprised four sets: 1) results obtained by the use of HPLC-DAD detection, 2) results obtained by the use of electrochemical detection (HPLC-ELC), 3) results for determining elements — total and water-extractable species, and 4) all data combined. Application of statistical methods allowed the samples to be classified into four groups: 1) Crataegus, Sambucus, 2) Equisetum, Polygonum and Viola, 3) Betula, and 4) Helichrysum, which were differentiated by characteristic patterns. PCA supported by CA, was the most suitable method, because it simultaneously allowed for reduction of multidimensionality of the databases, grouped the samples into four clusters, and made possible selection of the factors responsible for differentiation of the plant materials studied.
The influence of process conditions on the formation of thallium sulfide layers on polyethylene by the use of higher polythionic acid H2S33O6
Authors: Bružaitė Ingrida , Janickis Vitalijus
Published: January 2013

Thallium sulfide layers of varying composition form on the surface of low-density polyethylene (PE) when the PE films have been sulfurized in a solution of higher polythionic acid H2S33O6, and then immersed in the alkaline solution of thallium (I) sulfate. The concentration of sulfur sorbed-diffused into PE surface increases with the increase of the sulfurization time and concentration of higher polythionic acid solution. The concentration of thallium in the Tlx Sy layers depends on the sulfur concentration sorbed-diffused into PE, the concentration, and temperature of thallium (I) sulfate solutions. By chemical analysis of the obtained sulfide layers it was determined that the values of x and y in the TlxSy layers varies in the intervals: 1xy2S2 were identified by X-ray diffraction analysis in thallium sulfide layers. Scanning Electron (SEM) and Atomic Force (AFM) microscopies were used to characterize surface morphology of thallium sulfide layers. The films deposited on the PE surface have a non-homogeneous structure, and consist of separated islands.
Comparison characterization of copper selenide thin layers prepared on polyamide 6 films by sorption-diffusion method
Authors: Ivanauskas Remigijus , Janickis Vitalijus , Jasulaitienė Vitalija
Published: January 2013

Some earlier synthesized copper selenide (Cux Se) layers formed on the surface of polyamide 6 by sorption-diffusion method using potassium selenotrithionate (K2SeS2O6) as precursor of selenium were characterized by the XRD, XPS and SEM methods. According to the results of the SEM studies, the most uniform Cux Se layers form at the 2.5 h polyamide seleniumized duration at the temperature of 60°C. The thickness of layers, which dependeds on the duration of seleniumization, changed in the range of 0.8–3.2 µm. The XRD patterns of not previously studied Cux Se layers showed their phase composition of six copper selenides: Cu2Se, two phases of CuSe2, Cu3Se2, berzellianite, Cu2-x Se, and bellidoite Cu2Se. Analysis of the XRD and XPS data shows that the macrostructure and composition of the CuxSe layers depend on the conditions of formation of these layers.
Gender Study on Knowledge and Decision Making on Maternal Health Care in Nepal
Authors: Shrestha B
Published: January 2013

Background: The enjoyment of the highest attainable standard of health is one of the fundamental rights of every human being, without distinction of race, religion, and political belief, economic or social condition.(1). There still exist differences in the factors determining health and the burden of ill-health for women and men. The study is based on addressing the maternal health problems with gender perspectives, and the factors associated with health seeking practices. The main objectives of the study are to find out maternal health problem and gender analysis on decision making (household matters and health care) and the knowledge on danger signs in mother and newborn. Methods:The study is descriptive and cross sectional in design. Household surveys were conducted by the study team in 24 sample VDCs of Baglung, Dolakha and Ramechhap. Results: A total of 959 women were interviewed and 112 (11.40 percent) of them reported having faced emergency obstetric problems and about 5.6 percent of the respondents were found to be suffering from Uterus prolapse problems. The men were found getting more (81.2 percent) opportunities for education than women (58 percent). Women were found to be limited more to household activities that have low economic/monetary value (Women vs. Men: 41.83 percent Vs 4.49 percent) in comparison to men. The women’s status was found to be lower than that of men in all the indicators. The types of occupation were also clearly distinct between men and women in the study districts. Women had better knowledge (50 percent Vs 25 percent) on danger sign in mother and newborn but did not get opportunity of making decision to access health care in time. They were found having to follow their husband’s or in-laws’s decision. Conclusion: Appropriate initiative should be taken for women empowerment in order to develop women autonomy for maternal health care. DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7421 Health Prospect 2012;11:1-6
Knowledge and Attitude Regarding Major Risk Factors of Cardiovascular Diseases among 15-19 Year Old Students of Kathmandu District
Authors: Yadav KD , Wagle RR
Published: January 2013

Background: Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. Studies have shown that some people are at greater risk of developing cardiovascular disease than others. The major factors which increase the risks are tobacco chewing/smoking, raised blood cholesterol level, high blood pressure, physical inactivity, overweight and obesity, excessive alcohol consumption, age, sex and heredity. Although cardiovascular diseases typically occur in middle age or later, risk factors are determined to a great extent by behaviours learnt in childhood and continued into adulthood. Throughout the world, these risks are starting to appear earlier. Findings of various studies worldwide suggested that adolescents lacked knowledge regarding the risk of cardiovascular diseases and did not perceive themselves at risk for cardiovascular diseases. Methodology: A cross-sectional study was conducted among 144 adolescent students of grade XI and XII in one public and one private higher secondary schools of Kathmandu district. Samples were chosen purposively. Data were collected with the help of semi structured self administered questionnaire. Questionnaire was based on Likert scale. Data analysis was performed by using Statistical Package for Social Science - 17.0 for windows. Results: Overall 36.8 percent of respondents had good knowledge, 55.6 percent had fair knowledge and the remaining 7.6 percent had poor knowledge regarding the major risk factors of cardiovascular diseases. Sources of health information was found statistically significant (p=0.004) with the knowledge of respondents. Regarding overall attitude, the majority (47.9%) had the neutral attitude followed by positive (31.9%) and one fifth possessed negative attitude. Knowledge versus attitude regarding the major risk factors of cardiovascular diseases was found statistically significant (p=0.002). Conclusion: Results of this study revealed that good knowledge as well as positive attitude towards major risk factors of cardiovascular diseases among the adolescent students is unsatisfactory. Socio-demographic factors for good knowledge and good knowledge for the development of positive attitude play vital role. DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7422 Health Prospect 2012;11:7-10
Priority in Managing Health Intervention Program: A Critical View
Authors: Nayak SK
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7428 Health Prospect 2012;11:30-32
Systematic Reviews in Public Health
Authors: Paudel D
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7429 Health Prospect 2012;11:33-35
Ethical Perspective of Health Sector Reform Process in Nepal
Authors: Sapkota VP
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7430 Health Prospect 2012;11:36-39
Insight into Human Resources for Health Status in Nepal
Authors: Shrestha C , Bhandari R
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7431 Health Prospect 2012;11:40-41
Social Determinants of Health: Approach to Address the Underlying Socio-economic Disparities
Authors: Acharya P
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7432 Health Prospect 2012;11:42-44
The Public Health Discipline: Career at the Crossroads
Authors: Banstola A
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7433 Health Prospect 2012;11:45-46
Female Feticide: A Mass Murder
Authors: Bhandari PM , Mishra SR
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7434 Health Prospect 2012;11:47-49
Public Health Informatics: An Essence for Improving Public Health in Developing Nations
Authors: Paudel R
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7435 Health Prospect 2012;11:50-52
Baby-Friendly Hospital Initiative: Situation in Nepal
Authors: Subedi N
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7436 Health Prospect 2012;11:53-54
Injection Safety in Nepal
Authors: Neupane D
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7437 Health Prospect 2012;11:55-56
Elderly Abuse: An Emerging Public Health Problem
Authors: Sharma B
Published: January 2013

DOI: http://dx.doi.org/10.3126/hprospect.v11i0.7438 Health Prospect 2012;11:57-60
Variety Development Cost versus Variety Adoption in Major Cereals in Nepal
Authors: Shrestha Hari K , Manandhar Hira K , Regmi Punya P
Published: January 2013

This study was carried out to measure the research investment in major cereals, namely, rice, maize and wheat, and identify the general adoption status of their released varieties in Nepal. Financial resource use was derived from disaggregated expenditure whereas human resource use was approximated from full time equivalent (FTE) of researchers in each crop through questionnaire survey. Information regarding the farmers’ adoption was collected through group interaction with extension staff in selected hill and Terai districts from each of five geographical regions of the country. The variety development cost was Rs. 38.1 million in maize, 15.8 million in wheat, and 14.6 million in rice during 2001-2010 at 2000/01price. Of the total FTE researchers, 35 in rice, 28 in wheat and 18 in maize were involved in various disciplines of the crop research whereas 8 FTE researchers were involved in breeding of each of the crops. Among the most common rice varieties, Khumal-4 was adopted in 55% area in Kavre district, Radha-12 was adopted in 40% area in Sunsari district and Radha-4 was adopted in 70% area in Banke district in the main season. Indian hybrid maize was common in most of the Terai districts with maximum adoption in 95% area in Bara district. Among the popular wheat varieties, Gautam was common in hill and Terai districts with the adoption range from 30 to 50% of total wheat area. Compared with maize and wheat, adoption of improved rice varieties was relatively low since high yielding and suitable rice varieties were still lacking for various domains. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 7-15 DOI: http://dx.doi.org/10.3126/njst.v13i1.7393
Influence of Nitrogen on Growth Performance, Cut Flower Characteristics and Corm/Cormel Production of Gladiolus
Authors: Baral SP , Baral DR , Gautam DM , Pun UK
Published: January 2013

A study was carried out to access the influence of nitrogen level (100, 150, 200, 250, 300 kg/ha) on growth performance, cut flower characteristics and corm/cormel production of three varieties (American beauty, Interpret and Candyman) of gladiolus (Gladiolus hybrida L.) in the farmer’s field at Gunjanagar VDC, Chanauli, Chitwan, during September, 2010 to April, 2011. The experiment consisted of 15 treatment combinations laid out in 2 factorial randomized complete block design (RCBD) with 4 replications. Nitrogen levels significantly influenced growth performance, cut flower characteristics and corm/cormel production of gladiolus. Increasing the level of nitrogen up to 200 kg/ha, increased the rate of sprouting (97.33%), number of sprout/corm (2.05), taller plant (106.7cm) with more number of leaves (9.85), longest spike(86.58cm) with more number of florets/spike (16.73) were produced. Moreover, largest spike (92.62 g weight) having thicker (1.14 cm girth) and longest rachis (54.5 cm) were produced by 300 kg/ha. Size of daughter corm (5.8 cm) was highest with 300 kg/ha while number of the cormels per plants (89.45) was highest at 200 kg/ha nitrogen. Among three varieties, Candyman performed better with respect to early days to sprouting (15.1), early days to 50% sprouting (23.1), higher total sprouting percentage (97.6%), more number of leaves/plant at harvest (10.76), highest plant height (136.8 cm) at harvest, highest length of spike (81.6 cm), more weight of spike (81.78 g), thicker spike (1 cm) and longest rachis (51.1 cm). Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 25-31 DOI: http://dx.doi.org/10.3126/njst.v13i1.7395
Diets with High Amino Acid Density Can Improve Broiler Performance and Increase in Profit
Authors: Sharma NK , Sharma N
Published: January 2013

This study was conducted at the Institute of Agriculture and Animal Science (IAAS), Rampur, Chitwan for evaluating performance and carcass characteristics of broilers fed with two grades of diets varying in nutrient densities; high amino acid density (HG) diet and medium amino acid density (MG) diet. Two hundred and eighty straight run unsexed Cobb 500 broiler chicks were randomly assigned to two treatment groups with seven pens per treatment such that each pen consisted of 20 chicks. Control birds received MG diet in three phase feeding system viz. pre-starter: 1-15 days, starter: 16-25 days, and grower: 26-38 days. Treatment birds received HG diet in two phase feeding system viz. starter: 1-15 days, and grower: 16-38 days. The birds were provided with diets in crumbled form. At 38 days, with HG diet, feed conversion ratio (FCR) decreased (p<0.05) by 13.72%; body weight, carcass yield, and breast meat increased (p<0.05) by 15.45%, 2.92% and 10.46% respectively. Total feed intake and incidence of mortality among two treatments remained unaffected. At day 38, HG diet produced net profit of NRs. 20.97 per bird. It is suggested that HG diets give better performance with respect to weight gain, FCR, carcass yield and net profit compared to MG diets. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 33-37 DOI: http://dx.doi.org/10.3126/njst.v13i1.7396
Micropropagation of Bauhinia variegata L. from Tissue Culture
Authors: Singh BM , Wawrosch C , Joshi SD , Kopp B
Published: January 2013

Bauhinia variegate L. is a multipurpose tree and its micropropagation holds great promise in agroforestry. The sterilized seeds were first inoculated on Murashige and Skoog (MS) medium. Nodal cuttings from these seedlings grown in vitro were used as explants for micropropagation. Nodal cutting inoculated on the medium with various concentrations of BAP (benzyl-aminopurine) and NAA (£- naphthalene acetic acid) and separately generated varied results. Best propagation was recorded on MS medium supplemented with 1.0 ?M BAP with 0.05 ?M NAA. Propagated plants were successfully acclimatized and rooted in pots (6 cm diameter) containing soil and sand in1:1 ratio and then finally transferred to the field. All the data generated were analysed statistically using SPSS statistical package. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 39-41 DOI: http://dx.doi.org/10.3126/njst.v13i1.7397
Synthesis and Characterization of Nanostructured Blends of Epoxy Resin and Block Copolymers
Authors: Pandit Rajesh , Berkessel Albrecht , Lach Ralf , Grellmann Wolfgang , Adhikari Rameshwar
Published: January 2013

Polystyrene–polybutadiene block copolymers having different molecular architectures were epoxidized by using meta-chloroperoxybenzoic acid (MCPBA). Then, the blends with epoxy resin (diglycidyl ether of bisphenol-A; DGEBA) and their nanocomposites with boehmite and layered silicate nanofiller in presence of methylene dianiline (MDA) as a hardener were prepared. The epoxidized copolymers and the composites were characterized by Fourier transform infrared (FTIR) spectroscopy and microindentation technique. In this way, it was possible to tune the morphology of the nanostructured blends of the epoxy resin using the functionalized block copolymer as the template. The presence of nanostructured morphology was attested by the optical transparency of the blends as well as of the composites with nanofiller. The microhardness properties were improved by the incorporation of the nanoparticles, viz. boehmite and layered silicate. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 81-88 DOI: http://dx.doi.org/10.3126/njst.v13i1.7445
Analysis of Morphological and Mechanical Behaviors of Bamboo Flour Reinforced Polypropylene Composites
Authors: Bhandari Netra L , Thomas Sabu , Das Chapal K , Adhikari Rameshwar
Published: January 2013

In this paper, the bamboo flour (BF) reinforced polypropylene (PP) composites were studied with special attention to morphology of the composites and the effectiveness of chemically modified fillers to improve their mechanical properties. The composites of polypropylene with neat bamboo flour (BF) and treated bamboo flour (TBF) in different proportions were prepared by melt mixing followed by compression molding. The samples were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), tensile testing and water absorption testing. The results show that the alkali treated BF is compatible with polypropylene matrix than the neat one as the effects are reflected in the morphological features of the composites and their tensile mechanical properties. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 95-100 DOI: http://dx.doi.org/10.3126/njst.v13i1.7447
Adsorptive Separation of Metal Ions with Surface Modified Desmostachya bipinnata
Authors: Kour Jagjit , Homagai Puspa Lal , Pokhrel Megh Raj , Ghimire Kedar Nath
Published: January 2013

The biomass of Desmostachy bipannata (Kush, a religious plant of Hindus) was modified for the better adsorption of metal ions from aqueous solution. The FTIR and SEM images were used for the characterization of biomass. The adsorptive separation of metal ions from aqueous solution was studied with equilibrium isotherm and kinetic model. Langmuir adsorption isotherm and pseudo second order kinetic model showed better explanation for the adsorption process. The experimental results suggest that biomass from Kush can be used as an effective biosorbent for the removal of metal ions from aqueous solution. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 101-106 DOI: http://dx.doi.org/10.3126/njst.v13i1.7448
Status and Threats to Mugger Crocodile Crocodylus palustris Lesson, 1831 at Rani Tal, Shuklaphanta Wildlife Reserve, Nepal
Authors: Bhatt Harish P , Saund Tej Bahadur , Thapa Jham Bahadur
Published: January 2013

A study was carried out for preparing baseline information on water quality, population status and threats to Mugger crocodile, Crocodylus palustris Lesson at Rani Tal, Shuklaphanta Wildlife Reserve. Water quality analysis was conducted for three seasons (summer, autumn and winter) in the year 2008 - 2009. The study has found the physico-chemical contamination in the lake. The water quality parameters (dissolved oxygen, total hardness, free carbon dioxide, biological oxygen demand and ammonia) exceeded the normal range to support the Muggers. A survey around the lake recorded four adult Mugger crocodiles (>180 cm body length) basking in sandy and muddy bank during the investigation period. The lake is under pressure from diverse anthropogenic factors. The principal threats to the Mugger crocodile include water pollution, habitat destruction, sedimentation, food shortage, egg collection and seasonal fluctuation of water level. The total area and depth of the lake is diminishing due to encroachment by Phragmites karka and flash flood during monsoon. Conservation and proper management of the lake are urgently required. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 125-131 DOI: http://dx.doi.org/10.3126/njst.v13i1.7451
Effects of Sustainable Soil Management Practices on Distribution of Soil Organic Carbon in Upland Agricultural Soils of Mid-hills of Nepal
Authors: Dahal Nagmindra , Bajracharya Roshan M
Published: January 2013

An abundance of soil organic carbon (SOC) generally enhances the quality of lands for agriculture or forestry. Concentration of SOC varies in accordance to the type of land use, the inputs to the soil, and natural factors including climate and vegetation. SOC is vital for sustaining agricultural productivity which chiefly depends on both the inherent soil type and crop management practices affecting depletion or replenishment of organic matter over the years. Assessment of SOC concentration is a characteristic measurement of evaluating soil quality and the carbon sequestration potential of agricultural land. This study aims to assess SOC distribution on selected farmlands of Nepal’s mid-hills, where farmers have adopted sustainable soil management practices in non-irrigable hill terraces (“Bari” land) in comparison with those of surrounding Bari and forests where no such interventions are made. Thus the present study estimated SOC content of three types of land use – farmland with sustainable soil management practices (SSMP), farmland without sustainable management practices (Non-SSMP) and the community managed forest in four mountain districts of Nepal, namely Baglung, Dhading, Kavre and Okhaldhunga. This study found the average SOC stocks in the SSMP land in the range of 20 - 44 Mgha-1,those in non-SSMP agricultural areas 15 to 48 Mgha-1, and in the forested land 16 to 23 Mgha-1. In general, the abundance of SOC stocks are in the order of SSM>Non-SSM>Forests. The analysis indicates the high potential for carbon sequestration in hill agriculture lands through sustainable soil management. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 133-141 DOI: http://dx.doi.org/10.3126/njst.v13i1.7452
Recent Practices in Regional Modeling of Nonmotorized Travel
Authors: Liu Feng , Evans John E. (Jay) , Rossi Thomas
Published: January 2013

TRB Special Report 288: Metropolitan Travel Forecasting: Current Practice and Future Direction identified treatment of nonmotorized travel in regional models as one of eight modeling deficiencies and also as an advanced modeling practice. However, that report and other existing literature provided little information about recent practices. This paper reviews the current practice of incorporation of nonmotorized travel in regional travel demand models in the United States, especially the models of large metropolitan planning organizations developed over the past decade. Overall, some progress with the representation of nonmotorized travel in regional models has been made. This paper discusses and summarizes modeling approaches, including the variables and data used, data issues, and lessons learned; summarizes the major issues and challenges that modelers face when they incorporate nonmotorized travel into regional travel demand models; and makes recommendations for future improvements to models. Recent examples of different approaches to modeling of nonmotorized travel in regional models are also presented. The pros and cons of each approach, including their different data needs and different abilities to evaluate policies and planning scenarios, are discussed. When deciding on the approach that they will take to modeling of nonmotorized travel, agencies need to know the data requirements, model development efforts, and policy sensitivities desired. In the trip-based modeling framework, further enhancements can be made through the use of more refined zone systems and more accurate measurement of variables, although the activity-based modeling approach is more promising. Regardless of the approach taken, targeted and enhanced data on nonmotorized travel and nonmotorized travel infrastructure are greatly needed.
Integrated Land Use–Transport Model System with Dynamic Time-Dependent Activity–Travel Microsimulation
Authors: Pendyala Ram M. , Konduri Karthik C. , Chiu Yi-Chang , Hickman Mark , Noh Hyunsoo , Waddell Paul , Wang Liming , You Daehyun , Gardner Brian
Published: January 2013

The development of integrated land use–transport model systems has long been of interest because of the complex interrelationships between land use, transport demand, and network supply. This paper describes the design and prototype implementation of an integrated model system that involves the microsimulation of location choices in the land use domain, activity–travel choices in the travel demand domain, and individual vehicles on networks in the network supply modeling domain. Although many previous applications of integrated transport demand–supply models have relied on a sequential coupling of the models, the system presented in this paper involves a dynamic integration of the activity–travel demand model and the dynamic traffic assignment and simulation model with appropriate feedback to the land use model system. The system has been fully implemented, and initial results of model system runs in a case study test application suggest that the proposed model design provides a robust behavioral framework for simulation of human activity–travel behavior in space, time, and networks. The paper provides a detailed description of the design, together with results from initial test runs.
Statistical Analysis and Development of Crash Prediction Model for Roundabouts on High-Speed Rural Roadways
Authors: Isebrands Hillary , Hallmark Shauna
Published: January 2013

Roundabouts have proved to be effective in urban and suburban environments in the United States, but little has been reported on the effectiveness of roundabouts in rural environments on high-speed roadways. There is no question that roundabouts reduce the speeds of all vehicles at intersections and reduce the frequency of fatal and injury-related crashes. This research is the first comprehensive look at roundabouts in a rural environment with high-speed approaches. Nineteen intersections had ample comprehensive crash data to be evaluated and analyzed for safety performance. The findings validated the hypothesis that roundabouts in a rural environment as well as roundabouts in urban and suburban environments outperformed other intersection safety improvements. A before-and-after crash analysis was conducted for the 19 intersections by using a negative binomial regression model. Results showed statistically significant reductions for the total number of crashes (63%) and injury crashes (88%) when roundabouts were implemented. A before-and-after empirical Bayes estimation was also conducted, and the results were consistent, indicating a 62% to 67% reduction in total crashes and an 85% to 87% reduction in injury crashes at these rural intersections. Furthermore, results showed that injury-producing crash types, such as the angle crash, were reduced by 91%, and were statistically significant. Finally, this research produced crash prediction models at planning level for total and injury crashes at rural roundabouts on high-speed roadways. This supplements the models produced in NCHRP Report 572: Roundabouts in the United States and reported in the AASHTO Highway Safety Manual.
Examining Statewide Public Perceptions of Roundabouts through a Web-Based Survey
Authors: Savolainen Peter T. , Kawa Jacquelyn M. , Gates Timothy J.
Published: January 2013

Although roundabouts have been shown to provide significant safety and operational benefits, transportation agencies frequently encounter public opposition to their use. Consequently, a better understanding of public perceptions of roundabouts is critical to allow transportation agencies to address this issue. This study involved the implementation of a statewide Web-based survey of road user perceptions as they relate to roundabouts, which resulted in a total of 11,972 responses from road users throughout Michigan. The results of this survey show that public perceptions were mixed: 38.9% strongly opposed the use of roundabouts and 30.6% strongly supported their use. Respondents who had more experience with roundabouts tended to be more supportive. Younger respondents showed the most support, and support tended to decrease consistently with age. Female drivers, pedestrians, motorcyclists, and commercial motor vehicle drivers were all less likely to be supportive of roundabouts, whereas bicyclists were more supportive. Respondents were also asked to assess the relative safety and operational efficiency of roundabouts compared with traditional intersection configurations. Overall, 52.7% of respondents found roundabouts to be more operationally efficient, and an equal percentage found them to be less safe. The results show that the strongest indicators of roundabout support are linked to experience, making it imperative for road agencies to orient road users effectively to facilitate public acceptance of roundabouts. The results of this study provide valuable information that can be used to target public information and education programs intelligently toward appropriate audiences.
Analytical Method for Estimating Delays to Vehicles Traversing Single-Lane Roundabouts as a Function of Vehicle and Pedestrian Volumes
Authors: Hellinga Bruce , Sindi Alaa
Published: January 2013

Modern roundabouts that have unsignalized pedestrian crossings typically provide right-of-way to pedestrians, and therefore vehicles entering or exiting the roundabout must yield to pedestrians. The requirement that vehicles seek gaps in the pedestrian stream results in four distinct sources of delay to vehicles traversing the roundabout. Existing analytical methods for estimating delays to vehicles entering roundabouts typically consider only one of these four sources and ignore the other three. This paper presents an analytical model for estimating delays to vehicles traversing a single-lane roundabout. The model is based on gap acceptance and queuing models and explicitly estimates delays for each of the four sources for each origin–destination movement in the roundabout. The proposed model is evaluated for a typical single-lane roundabout by comparing the model estimates with estimates obtained from the VISSIM simulation model and the Highway Capacity Manual (HCM) method for a range of traffic and pedestrian volumes. The results of this evaluation demonstrate that the proposed model is superior to the HCM method and provides delay estimates that are comparable with those obtained from microsimulation modeling. Further research is recommended to validate the model results by using field data.
Delay Analysis of Single-Lane Roundabout with a Slip Lane under Varying Exit Types, Experimental Balanced Traffic Volumes, and Pedestrians, Using Microsimulation
Authors: Al-Ghandour Majed , Schroeder Bastian , Rasdorf William , Williams Billy
Published: January 2013

A slip lane facilitates right-turning traffic flow, reduces approach delay, and reduces conflict points within a roundabout. In this paper the delay performance of a single-lane roundabout with an adjacent slip lane is modeled with the VISSIM microsimulation tool for three slip lane exit types (free-flow, yield, and stop) and the results are compared with a roundabout having no slip lane. The VISSIM assessment considers four experimental traffic percentage turning volume distributions as balanced flow scenarios (total traffic flow into and out of every roundabout approach is the same). Simulated slip lane right-turning traffic volumes range from 50 to 500 vehicles/h, and the four pedestrian volume levels range from 0 to 100 pedestrians/h. VISSIM results confirm that average delays in a roundabout with a slip lane are a function of circulating conflict volumes and are related exponentially to slip lane volumes regardless of the slip lane exit type. Results also indicate that a free-flow slip lane exit type best reduces total average delay in the roundabout and in the slip lane itself. Yield and stop slip lane exit types also reduce the roundabout total average delay but to a lesser degree. Finally, at a higher traffic volume, a free-flow slip lane exit type can increase roundabout delay from 6.6 to 34.7 s/vehicle if drivers must yield the right-of-way to high pedestrian traffic (100 pedestrians/h) crossing a free-flow slip lane (priority rule).
Turning Angle Effect on Emergency Egress: Experimental Evidence and Pedestrian Crowd Simulation
Authors: Dias Charitha , Sarvi Majid , Shiwakoti Nirajan , Burd Martin
Published: January 2013

Interactions between humans and physical features of the escape area can considerably impede collective movement of panicked crowds. The turning angle is one of the physical features that must be designed carefully as angled or circuitous egress routes such as corridors are unavoidable features of mass gathering places. Previous studies on crowd disasters have highlighted the importance of considering turning movements, particularly under panic situations. However, few qualitative and quantitative studies have addressed this phenomenon. One reason for the limited study might be the lack of empirical data to validate the predictions from mathematical models. In this work, empirical data collected from panicking ants and data from a crowd dynamic simulation model are used to describe how right-angled egress paths work ineffectively compared with straight egress paths during the collective panic egress. Empirical data with panicking ants and simulation results show that right-angled egress paths are more than 20% ineffective compared with straight paths of the same dimensions. That is, right-angled egress paths decrease the flow rate and increase the escape times significantly compared with those of straight egress paths. Results suggest that it is possible to study evacuation strategies and design solutions that can prevent crowd disasters by using empirical data collected from biological entities.
Modeling Risk Attitudes in Evacuation Departure Choices
Authors: Dixit Vinayak V. , Wilmot Chester , Wolshon Brian
Published: January 2013

The decision of whether and when to evacuate can be characterized as decision making under risk. Presently, most models assume linear utility functions through which it is impossible to disentangle factors that influence risk attitudes and other factors that affect decision making under risk. There is a need to disentangle and study factors that affect risk attitudes from factors that affect an evacuee's preparation time. The aim in doing so is to provide planners and practitioners with an ability to measure a person's risk attitude and develop appropriate strategies that could motivate people to evacuate. This study is expected to connect the theory of risk developed in economic theory with behavior under threat. The paper uses the Hurricane Andrew response data in conjunction with time-dependent data on the probability of a hurricane strike and the category of the hurricane data to develop a model for evacuation departure choice. A constant relative risk aversion specification is used to model risk attitudes. The process of an evacuation is abstracted as an individual being given a choice between two lotteries: either to stay or leave. The results show that the model is able to predict the total number of evacuees and the time varying evacuation rates with reasonable accuracy. Factors such as time of day, length of time spent in a region, and whether a mandatory evacuation order was issued affected risk attitudes. The presence of children affected the amount of time spent preparing if the family decided to stay.
Using Crash Data to Develop Simulator Scenarios for Assessing Novice Driver Performance
Authors: McDonald Catherine C. , Tanenbaum Jason B. , Lee Yi-Ching , Fisher Donald L. , Mayhew Daniel R. , Winston Flaura K.
Published: January 2013

Teenage drivers are at their highest crash risk in their first 6 months or first 1,000 mi of driving. Driver training, adult-supervised practice driving, and other interventions are aimed at improving driving performance in novice drivers. Previous driver training programs have enumerated thousands of scenarios, with each scenario requiring one or more skills. Although there is general agreement about the broad set of skills needed to become a competent driver, there is no consensus set of scenarios and skills to assess whether novice drivers are likely to crash or to assess the effects of novice driver training programs on the likelihood of a crash. The authors propose that a much narrower, common set of scenarios can be used to focus on the high-risk crashes of young drivers. Until recently, it was not possible to identify the detailed set of scenarios that were specific to high-risk crashes. However, an integration of police crash reports from previous research, a number of critical simulator studies, and a nationally representative database of serious teen crashes (the National Motor Vehicle Crash Causation Survey) now make identification of these scenarios possible. In this paper, the authors propose this novel approach and discuss how to create a common set of simulated scenarios and skills to assess novice driver performance and the effects of training and interventions as they relate to high-risk crashes.
Local disease control for spinal metastases following “separation surgery” and adjuvant hypofractionated or high-dose single-fraction stereotactic radiosurgery: outcome analysis in 186 patients
Authors: Laufer Ilya , Iorgulescu J. Bryan , Chapman Talia , Lis Eric , Shi Weiji , Zhang Zhigang , Cox Brett W. , Yamada Yoshiya , Bilsky Mark H.
Published: January 2013

Object

Decompression surgery followed by adjuvant radiotherapy is an effective therapy for preservation or recovery of neurological function and achieving durable local disease control in patients suffering from metastatic epidural spinal cord compression (ESCC). The authors examine the outcomes of postoperative image-guided intensity-modulated radiation therapy delivered as single-fraction or hypofractionated stereotactic radiosurgery (SRS) for achieving long-term local tumor control.

Methods

A retrospective chart review identified 186 patients with ESCC from spinal metastases who were treated with surgical decompression, instrumentation, and postoperative radiation delivered as either single-fraction SRS (24 Gy) in 40 patients (21.5%), high-dose hypofractionated SRS (24–30 Gy in 3 fractions) in 37 patients (19.9%), or low-dose hypofractionated SRS (18–36 Gy in 5 or 6 fractions) in 109 patients (58.6%). The relationships between postoperative adjuvant SRS dosing and fractionation, patient characteristics, tumor histology–specific radiosensitivity, grade of ESCC, extent of surgical decompression, response to preoperative radiotherapy, and local tumor control were evaluated by competing risks analysis.

Results

The total cumulative incidence of local progression was 16.4% 1 year after SRS. Multivariate Gray competing risks analysis revealed a significant improvement in local control with high-dose hypofractionated SRS (4.1% cumulative incidence of local progression at 1 year, HR 0.12, p = 0.04) as compared with low-dose hypofractionated SRS (22.6% local progression at 1 year, HR 1). Although univariate analysis demonstrated a trend toward greater risk of local progression for patients in whom preoperative conventional external beam radiation therapy failed (22.2% local progression at 1 year, HR 1.96, p = 0.07) compared with patients who did not receive any preoperative radiotherapy (11.2% local progression at 1 year, HR 1), this association was not confirmed with multivariate analysis. No other variable significantly correlated with progression-free survival, including radiation sensitivity of tumor histology, grade of ESCC, extent of surgical decompression, or patient sex.

Conclusions

Postoperative adjuvant SRS following epidural spinal cord decompression and instrumentation is a safe and effective strategy for establishing durable local tumor control regardless of tumor histology–specific radiosensitivity. Patients who received high-dose hypofractionated SRS demonstrated 1-year local progression rates of less than 5% (95% CI 0%–12.2%), which were superior to the results of low-dose hypofractionated SRS. The local progression rate after single-fraction SRS was less than 10% (95% CI 0%–19.0%).