Wood specific gravity of some tree species in the Garhwal Himalayas, India

Estimation of terrestrial biomass depends critically on reliable information about wood specific gravity of forest trees. In recent years, wood specific gravity has become more important when exploring the universality of functional traits of plants and estimating their global carbon stocks. To estimate their specific gravity, wood samples were collected from a total of 34 tree species, 30 from lower elevations and 4 from upper elevations in the Garhwal Himalayas, India. The results show that the average wood specific gravity was 0.631 （ranging between 0.275 ± 0.01 and 0.845 ± 0.03） for the species at lower elevations and 0.727 （ranging between 0.628 ± 0.02 and 0.865 ± 0.02） for the upper elevations. The average wood specific gravity for the upper elevation species was 9.6% greater than that for the species at lower elevations. Aegle marmelos among the lower elevation species and Quercus leucotrichophora among the upper elevation species had the highest wood specific gravity, which were 0.845 ± 0.03 and 0.865 ± 0.02, respectively.

Forest aboveground biomass estimates in a tropical rainforest in Madagascar: new insights from the use of wood specific gravity data

To generate carbon credits under the Reducing Emissions from Deforestation and forest Degradation program（REDD＋）, accurate estimates of forest carbon stocks are needed. Carbon accounting efforts have focused on carbon stocks in aboveground biomass（AGB）.Although wood specific gravity（WSG） is known to be an important variable in AGB estimates, there is currently a lack of data on WSG for Malagasy tree species. This study aimed to determine whether estimates of carbon stocks calculated from literature-based WSG values differed from those based on WSG values measured on wood core samples. Carbon stocks in forest biomass were assessed using two WSG data sets：（i） values measured from 303 wood core samples extracted in the study area,（ii） values derived from international databases. Results suggested that there is difference between the field and literaturebased WSG at the 0.05 level. The latter data set was on average 16 % higher than the former. However, carbon stocks calculated from the two data sets did not differ significantly at the 0.05 level. Such findings could be attributed to the form of the allometric equation used which gives more weight to tree diameter and tree height than to WSG. The choice of dataset should depend on the level of accuracy（Tier II or III） desired by REDD＋. As higher levels of accuracy are rewarded by higher prices, speciesspecific WSG data would be highly desirable.

Variations in wood anatomical properties and specific gravity of half sib progenies of Populus deltoides

We studied radial and inter-progeny variations in the dimen- sions of the wood elements and specific gravity of 21 half sib progenies of Populus deltoides Bartr. ex Marsh. The female parents of half sib progenies were G48 and $7C13 clones. Variance ratio （F） test indicated that inter-progeny variations in the dimensions of wood elements and specific gravity were significant for all wood traits while variations were significant for radial location for specific gravity only. Hierarchical clus- ter analysis was done by Squared Euclidean Distance for all of 21 proge- nies considering six wood traits. 21 progenies were grouped into 4 clus- ters. Cluster 1 was the largest cluster with 11 progenies, whereas cluster 3 had only one progeny. Selected progenies in clusters 3 （progeny 155, male） and 4 （progeny 108, 196, both female） were highly divergent from the other progenies so they were used in combinations as parents of hybrids to develop new clones with desired characters. Progeny 155 showed higher growth, fiber dimensions, and specific gravity, thus, should be used for the development of new clones.

Specific gravity of some woody species in the Srinagar Valley of the Garhwal Himalayas, India

In this study, we investigated the specific gravity of wood samples collected from a total of 31 woody spe- cies, consisting of 20 trees, 10 shrubs and one species of bamboo from sub-tropical regions of Garhwal Himalayas, In- dia. Results show that among these woody species, the specific gravity of trees ranged from 0.34 for Erythrina suberosa to 0.83 for Albizia procera. For shrub species the specific gravity of Ricinus communis was 0.39 and that of Dodonaea viscosa 0.93. The average specific gravity of trees was 0.58 and of shrubs 0.66.

Evaluation of Light Specific Gravity Ropivacaine Combined with Sufentanil in Hip Arthroplasty at An Advanced Age

combined with sufentanil in elderly patients undergoing hip replacement.Methods:89 elderly patients with hip arthroplasty from July 2019 to September 2020 were randomly divided into experimental group and control group.The experimental group was anesthetized with light specific gravity ropivacaine combined with sufentanil.The control group was anesthetized with equal specific gravity ropivacaine to compare the effect of anesthesia and the incidence of adverse reactions.Results:there was no significant difference in sensory recovery time and motor recovery time between the experimental group and the control group(P>0.05),and the incidence of adverse reactions between the two groups was low.The sensory block time in the experimental group was shorter than that in the control group(PP>0.05).Conclusion:ropivacaine combined with sufentanil subarachnoid anesthesia is more effective in elderly patients undergoing hip arthroplasty,and the safety of the anesthesia scheme is higher,which will not lead to serious adverse reactions during operation.Moreover,the application of the anesthesia scheme can effectively improve the analgesic effect during and after operation,and the clinical application value is high.

Uropathogens and diagnostic potential of pH and specific gravity in a rural community of Nigeria

Objective:To assess the association between urine pH and specific gravity(SG)and occurrence of urinary tract pathogens involved in urinary tract infection(UTI)in school pupils.Methods:Laboratory culture techniques and biochemical tests were carried out to identify the UTI-associated bacteria in school pupils’urine of United Nursery and Primary School,Ilara-Remo,in Ikenne Local Government area,Ogun State,Nigeria.Urine dip-stick tests were carried out on the samples to take pH and SG measurements.Results:The prevalence of urinary tract pathogens in the study population was 82.4%.This prevalence was not gender and age dependent(P>0.05).Escherichia coli(E.coli)(37.0%)and Klebsiella(0.9%)were the highest and least prevalent uropathogens.There was significant increase in proportion of subjects diagnosed with E.coli(37.5%),Staphylococcus aureus(32.0%),Klebsiella(57.1%)in pH 9,pH 6 and pH 8,respectively(P<0.05).However,an increase in proportion of individuals diagnosed with Proteus occurred in pH 6 and 9(31.3%each);these proportions were not significant compared with results in other pH categories(P>0.05).There were significant increase in proportion of subjects diagnosed with E.coli(50.0%),Proteus(56.3%),Staphylococcus aureus(44.0%),Klebsiella(71.4%)in SG 1.010,1.015,1.015 and 1.010,respectively(P<0.05).Conclusion:Therefore,the urine pH 9 and SG 1.010-1.015 are the best diagnostic indicators of UTI-associated uropathogens in school children.

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

Background:No studies have documented long-term trends in aboveground biomass(AGB)for mixed-dipterocarp forests(MDF),the dominant rain forest type in tropical wet equatorial Asia.In our study,we sought to document such trends over forty years across three sites representing lowland to lower montane elevations.Methods:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth forest.We measured trees for diameter at breast height that we identified to species and tagged.We took wood samples to calculate species wood-specific gravity.We re-measured plots in 1998 and again in 2018.Results:We show standing AGB for all sites combined to be 517.52 Mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 Mg·ha^(-1).No differences exist among sites in AGB primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the same.Relatively few species represented a high proportion of the AGB with the top five species comprising between 34%and 65%,depending upon site and year sampled.One species,Mesua nagassarium,represented a disproportionately large amount of AGB and decline over time,particularly at the low elevation site.Conclusions:Our results are directly relevant to estimating AGB and standing carbon sequestered in MDF.Our study is the first to demonstrate varying but overall,declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in MDF difficult over wide regions.

Performance and variability patterns in wood properties and growth traits in the parents, F1 and F2 generation hybrid clones of Populus deltoides

The performance and variability patterns in the wood element’s dimensions, specific gravity and growth parameters namely ramet height and GBH were evaluated in 16 clones of parents, F1 and F2 hybrids of Populus deltoides Bartr. ex Marsh. Ramet radial variations were nonsignificant, while inter-clonal variations due to interaction of clone/replication were significant for all the wood traits except vessel element length. Inter-clonal variations were significant only for fiber length and fiber wall thickness. Fiber length and specific gravity were significantly higher in female, while wall thickness and vessel element length were higher in male clones. Female parents （G48 and S7C8） showed higher fiber length and specific gravity than of the male parent （G3）, while vessel diameter and wall thickness were higher in male par- ent （G3）. There is not much difference in fiber length and vessel element’s dimensions among the parents, F1 and F2 generation hybrid clones. Specific gravity did not showed any trend for parents, F1 and F2 generations. Generally female clones showed higher growth rate. Broad sense heritability for wood traits ranged from 0.143 （fiber length） to 0.505 （fiber wall thickness）, while for growth traits it was 0.374 （GBH） and 0.418 （height）. Genetic gain for all the wood and growth traits was positive for most of the wood traits. The highly divergent male clone （78） and female clones （S7C8, G48, W/A 49） in number of combinations could be used for developing new hybrids of desired wood traits to develop new clones.

Effect of growth on wood traits in seed-raised plantations of Dalbergia sissoo Roxb.

We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from 925 to1,287 lm, fiber-diameter was 19–23 lm, wall thickness was4.2–5.4 lm, vessel-element-length was 152–188 lm, vesselelement-diameter was 152–200 lm, and specific gravity was0.59–0.72. Growth parameters including tree height, diameter at breast height, net primary productivity and net ecosystem productivity were significantly and positively correlated.Growth parameters showed non-significant positive relationships with fiber-length, fiber diameter, wall thickness, vessel element length, and vessel element diameter. The trend of wood traits increased with growth. Specific gravity showed non-significant negative relationships with growth parameters. Although the growth rate had varied relationships with wood properties, as reported by various workers, the wood element dimensions showed no significant relationship with growth parameters and there was little effect of growth rate on wood traits in seed-raised plantation of D. sissoo.

Determination of Crystal Structure of Britholite-Y

Britholite-Y is milkwhite, rosy in colour. The measured specific gravity is 4.35, with Ng′ = 1.791, Np′ = 1.784. As determined by electron microprobe, its crystal formula is (Y2.82Ca1.58Ce0.27Dy0.21Er0.11)5 [(Si2.95P0.05)3O12](OH,F), space group = C22-P21, a = (0.9504±0.0005) nm, b = (0.9414±0.0004) nm, c = (0.6922±0.0002) nm, r = (119.71±0.04)°, V = (53.79±0.04) nm3, Z = 2. Least-squares refinements with 2272 independent reflection (F0>3σ|F0|) yielded R = 0.111. The change of symmetry group P63/m of apatite to P21 of britholite-Y results from the shifts of Y, Ca, Si, O and (OH) atoms (anions) from the pseudohexagonal P63/m equivalent positions (6h), (4f), (12i) and (2a) as produced by distortion of the polyhedra with 7-, 9-, and 4-corners. The substitution of Ca in apatite for Y and the order distribution of atoms Y and Ca on the equivalent positions (6h) and (4f) have contributed to the distortion of 7- and 9- cornered polyhedra. The substitutions of Si4+ for P5+ and OH- for F- may also be effected. The crystal chemistry of apatite-group minerals is also discussed.

Maturity indices of Indian horse-chestnut (Aesculus indica Colebr.) seeds under temperate Kashmir conditions

Our study on maturity indices of Aesculus indica Colebr. seeds was conducted under temperate Kashmir conditions in 2006. Seed collection was started from 15 July and continued until the maturation of seeds in December. The seeds were harvested fortnightly from identified trees and on each collection date maturity indices, viz. seed color, seed weight, moisture content, seed dimension, specific gravity and germination percentage were recorded. The study revealed that at the time of maturity （Nov.-Dec.） the seed color was a shiny chocolate brown, with a moisture content of 58.37% and a specific gravity of 0.82. Germination was maximum （80%） at its maturity with a maximum seed weight of 52.03 g per seed. We recommend that the seeds should be collected before their natural disposal.

Effect of Bio-Disc on Distillate Yield and Crude Oil Properties

The market worth of the crude oil transported to the international market has a great influence on the crude’s physical properties, as such demands that certain desirable physical properties ought to be possessed. The distillation of crude oil is the first process in the sequence of refining operation and is key to refinery operations profitability. In this work, five crude oil samples were collected from a reservoir in the Niger Delta designated as S11A, S12A, S13A, S14A and S15A. Sample S11A was not treated with bio-disc while samples S12A-S15A were treated with bio-disc at different number of times. This was necessary to ascertain the effect of the bio-disc on crude oil physical properties and their distillate yield. After the treatment, the specific gravity, American Petroleum Institute (API), pour point, flash point and viscosity of the treated and untreated crude samples were determined and then the samples distilled with a distillation tester. From the results obtained, the bio-disc had a great influence on the physical properties of the samples as well as on the distillate yield. The specific gravities of the oil samples decreased as the number of times the samples were treated with bio-disc increases and this in turn increased the crudes’ API. The pourpoint and viscosity decreased with increase in number of treatments of crude samples with bio-disc. As the number of treatments increased, the crude samples which were originally paraffinic were tending towards being naphthenic. The flash point and distillate yield increased with increase in number of treatments of crude samples with bio-disc. Thus, treatment of crude oil with bio-dic alters the physical properties of the crude.

Utilization of Oil Properties to Develop a Spreading Rate Regression Model for Nigerian Crude Oil

The target of this study is to develop a spreading rate regression model capable of predicting rate of spread of Nigerian crude oil spills on water. The major factors responsible for spreading rate of crude oil on water were considered, namely surface tension, viscosity, and specific gravity/American Petroleum Institute degree (0API), all at specified temperature values. The surface tension, viscosity and density parameters were interactively measured under controlled factorial analysis. The spreading rate of each crude oil was determined by artificially spilling them on laboratory calm/stagnant water in a rectangular tank and their averages were also computed. These averages were used to develop a regression model equation for spreading rate. The model developed indicated that an average spreading rate was 3.3528 cm/s at 37.5°C and the predictive regression model is evaluated with the interactions of specific gravity, viscosity and surface tension. It is convenient to state that the model will predict the spread rate of crude oils which possess imputed physicochemical properties having pour point averaged 15.5°C on calm seawater.

Influence of atomic densities on propagation property for ultrashort pulses in a two-level medium

The influence of atomic densities on the propagation property for ultrashort pulses in a two-level atom (TLA) medium is investigated. With higher atomic densities, the self-induced transparency (SIT) cannot be recovered even for 2πultrashort pulses. New features such as pulse splitting, red-shift and blue-shift of the corresponding spectra arise, and the component of central frequency gradually disappears.

How did Archimedes discover the law of buoyancy by experiment？

After Archimedes and Vitruvius era, for more than 2000 years, it has been believed that the displaced water measurement of golden crown is impossible, and at his Eureka moment, Archimedes discovered the law of buoyancy （Proposition 7 of his principles） and proved the theft of a goldsmith by weighing the golden crown in water. A previous study showed that a small amount of displaced water was able to be measured with enough accuracy by the introduced method. Archimedes measured the weight of displaced water. He did not find the law of buoyancy but rather specific gravity of things at the moment. After which, Archimedes continued to measure the specific gravity of various solids and fluids. Through these measurements, he reached the discovery of the law of buoyancy directly by experiment. In this paper, the process to the discovery of Archimedes＇ principle （Proposition 5） is presented.

Experimental study on average movement characteristics of bed-load particles

The three-dimensional movements of bed-load particles in an open channel with different grain diameters and different specific gravities under the conditions of different hydraulic gradient are measured by means of particle tracking velocimetry(PTV)technique.The average movement characteristics of the particles are analyzed by statistics.The results show that the longitudinal average velocities of the particles neither agree with the law suggested by Einstein nor obey the law assumed by Bagnold.Einstein’s law is that the particle velocity is equal to 11.6 times of shear velocity,and the Bagnold’s law assumes the velocity equal to the difference between flow velocity at corresponding water depth and settling velocity of particle.Two formulas for determining the velocity of particle in the forms of expression given by Einstein and Bagnold are obtained according to the statistical results of experimental data,respectively.