bluuebunny/crossref_metadata_2025 huggingface dataset:
When Do Surfactant-Based Acids Work as Diverting Agents?
Authors: Al-Ghamdi A. H. , Mahmoud M. A. , Hill A. D. , Nasr-El-Din H. A.
Published: February 2010

The purpose of matrix stimulation in carbonate reservoirs is to bypass the damaged zones and increase the effective wellbore area. This can be achieved by creating highly conductive flow channels known as wormholes. A further injection of acid will follow the wormhole path where the permeability has increased significantly, leaving substantial intervals untreated. This problem can be significant as the contrast in permeability increases within the target zones. Diverting materials such as surfactant-based acids play an important role in mitigating this problem. Several papers published in the literature aimed to verify the diversion capability and the performance of the self-diverting acids. However, most of the parallel-coreflood experiments, if not all, used relatively short cores (2 to 6 inches in length).

In this paper, acidizing experiments were conducted using two 20-inch long cores with different permeabilities. Carbonate cores were used with a permeability of 5 to 150 md and the total flow rate was varied from 3 to 20 cm3/min. The initial contrasts in permeability between the two cores ranged from 2 to 15 fold. To characterize the wormholes generated, a computerized tomography (CT) was used to generate 3-D images to describe the shape of the wormholes in both cores.

Several periods were identified from the shape of the flow rate distribution entering each core. Acid injection rate was found to influence the efficiency of surfactant to divert acid. Acid diversion was noted to be most efficient at low flow rates (3 cm3/min). No significant diversion was noted at higher flow rates (> 6 cm3/min). Also, no significant diversion was noted at high initial permeability ratios at least for the given core length. In conjunction with the experimental study, an analytical model was developed to verify the experimental results obtained with regular acids.
Post-Fracturing Fluid-Recovery Enhancement With Microemulsion
Authors: Agee D. , Yudho A. , Schafer L. , Thouvenin E. , Grant G. , Garnier A. , Wijanarko A.
Published: February 2010

The fields of East Kalimantan, Indonesia contain several depleted gas zones of medium permeability (0.1 to 300 mD). Though the permeability is quite good for gas bearing formations, the majority of the wells targeting these sands have failed to produce at expected rates. In the 1980s, hydraulic fracturing was introduced to the area in an attempt to increase production. The treatments yielded limited success with many wells actually producing less after being fractured. This led operators in the area to believe that the formations could be water sensitive with damage from the injected fluids causing the poor results after fracturing. As laboratory testing has ruled out water-sensitive mineralogy, the suspected cause of damage has been attributed to a decrease in relative permeability to gas after the fracturing fluid has penetrated the pore throats (water block). The water block conclusion is supported by the low percentage of injected fluids that are returned after the treatment.

In 2007, VICO performed four fracturing treatments using a conventional surfactant to aid in post-frac cleanup. Only 2 of the 4 wells that were fractured produced after the treatment. Again, a common problem between the wells was the poor return of treatment fluids during cleanout. The limited success of these treatments indicated the water block issue had not been resolved. After reviewing the results of the first four wells, three additional fracturing treatments were placed in similar reservoirs using a microemulsion additive instead of the surfactant. Though laboratory testing in cores between 1 and 8.5mD failed to show a significant difference between the microemulsion and surfactant, the wells fractured with the microemulsion additive consistently outperformed those fractured previously in terms of returned treatment fluids and incremental production. Paktinat et al. (2006) wrote that the use of fracturing fluids with microemulsion in unconventional tight gas reservoirs can help increase production by increasing the relative permeability to gas in the area surrounding the fracture. Our study shows that similar benefits can also be achieved in depleted gas reservoirs with permeabilities greater than 1 mD, even if the benefits can not be clearly demonstrated under laboratory conditions.
Perforating for Fracturing: Theory vs. Field Experiences
Authors: Ceccarelli R. L. , Pace G. , Casero A. , Ciuca A. , Tambini M.
Published: February 2010

Perforations provide the communication between wellbore and formation resulting in a communication path both for injected and produced fluids from the reservoir. Many perforation parameters such as shot phasing, charges size, shot density, type of gun and length of interval play an important role in the correct execution of a fracturing job. Those parameters have to be engineered to guarantee easy formation breakdown, minimize near wellbore restrictions (or tortuosity) and be big enough to prevent proppant bridging while considering fracture treatment size, proppant concentration, proppant size and treatment flow rate. Ideal fracture initiation perforations would create a minimum injection pressure initiating a single fracture (not for shale gas reservoirs) and generate a fracture with minimum tortuosity at an achievable fracture initiation pressure. Best perforation practices are important during the decisional and designing phase but have to be confirmed by field experience even in well known reservoir where formation heterogenity, well deviation, local stress anomalies, cement bound and many other factors can result in unexpected behaviors that could compromise the success of the stimulation treatment.

In the following paper a briefly description of perforating theories and different field experiences are reported showing test results executed for a better perforation strategy. Unexpected deviations both from theory recommendations and from field analogies were analyzed as well as successful and unsuccessful remedial solutions in cases of injectivity issues.
Single-Trip Multiple-Zone Completion Technology Has Come of Age and Meets the Challenging Completion Needs of the Gulf of Mexico's Deepwater Lower Tertiary Play
Authors: Burger R. , Grigsby T. , Ross C. , Sevadjian E. , Techentien B.
Published: February 2010

The Gulf of Mexico hydrocarbon potential has confounded "naysayers," who once called it the Dead Sea. The planned development of the ultra deepwater lower-tertiary play is the latest chapter in the Gulf of Mexico's ongoing viability as a major hydrocarbon basin. To economically develop this challenging lower-tertiary play requires new completion technology to handle the long, stacked pay intervals. This has generated renewed interest in multi-zone completion technology. This technology is viewed as a method that hs the potential to increase completion efficiency as well as reduce overall completion cost. These systems were once considered too complex and risky for deepwater operations; but the hope that the technology could provide increased completion efficiency and alleviate some of the issues inherent with stacked completions in deepwater has again renewed interest in pursuing this technology. Thus, the latest generation of robust, cased-hole single-trip multiple-zone frac-pack completion systems has been developed. The renewed interest for development of these systems has also been the driving force for development of an openhole multiple-zone frac-pack completion system that could ultimately provide reductions in well construction cost.

This paper will provide the reader with a brief development history of cased-hole, single-trip multiple-zone completion systems and then the focus will shift to the latest generation of tool systems. The discussion will also include the reasons why the previous systems have not proliferated globally as an accepted mainstream sand-face completion technique. The sand face is one part of the completion equation. The methodology of integrating the uphole completions to the multizone sand-face completion will be briefly discussed.

The improved functionality of the newest multizone systems will be described and compared to the previous-generation systems. The presentation will cover the integration testing to qualify the newest multiple-zone system and will cover trial well installations. Deepwater case histories will be presented, if available by presentation time.
Upscaling of Deep Bed Filtration from Core to Near-Wellbore Region
Authors: Vaz A. S. , Bedrikovetsky P. , Furtado C. , de Souza A. L.
Published: February 2010

Deep bed filtration of suspensions in porous reservoirs with particle retention by the rock and consequent permeability decrease, takes place during seawater injection and re-injection of produced water in waterflood projects. The invasion of drilling fluid occurs during drilling and affects the return permeability and well index. Deep bed filtration of migrated fines during oil production from heavy-oil, high-clay-contents or low consolidated reservoirs affects well index impairment and fines production. The mathematical-modeling-based reliable prediction of suspension transport in rocks is the essential part of planning and design of the above mentioned technologies.

The mathematical models for suspension flow in homogeneous porous media are well developed and validated by numerous laboratory studies. Nevertheless, the above mentioned processes of oil production occur in near-well regions, where the drilling-induced heterogeneity adds to the natural heterogeneity. Yet, the models and laboratory studies for deep bed filtration in micro heterogeneous rocks are poorly available in the literature.

In the current paper, the analytical models for colloidal-suspension filtration in composite cores with different types of heterogeneity are derived. The breakthrough concentrations during suspension flow in cores with in-parallel, in-series and combined types of heterogeneity, as obtained from laboratory corefloods and from modeling, are found to be in a good agreement.

The analytical formulae for effective filtration coefficient for in-parallel, in-series and combined types of heterogeneity allow proposing the upper and lower estimates of upscaled filtration coefficient for flows in heterogeneous numerical grids with homogeneous cells.
Comparison of Scale Control Challenges between Production and PWRI Wells
Authors: Mackay Eric J.
Published: February 2010

The oilfield industry is familiar with the challenges associated with controlling inorganic scale precipitation in production wells. There are well-established techniques and procedures that may be followed, including modelling and test work in the laboratory, and prevention and removal in the field. While the rate of scale accumulation is not routinely predicted as yet, know-how developed over decades of scale management means that engineers have access to the expertise and tools to be able to manage scale effectively in a large range of production scenarios.

However, similar expertise and tools have not yet been fully developed and applied for controlling scale precipitation in Produced Water Re-Injection (PWRI) wells. This is a particular concern in scenarios where the injection brine has a scaling tendency, for example if it consists of a mix of incompatible brines.

Some of the existing tools used for scale management in production wells may be used, such as thermodynamic predictions. In addition, of late there has been significant work on modelling rates of deposition in such systems. However, there are key differences between conventional production scenarios and PWRI systems in terms of scale inhibition. In production systems the reservoir may be considered as an upstream batch reactor, in which, if the precipitation reactions are occurring far enough from the wells, there is a benefit in terms of a reduced scaling tendency at the producers; hence the demands on inhibitors are lowered. In injection systems, however, there is no such sacrificial upstream reactor, and so the demands of scale inhibition may be more stringent.

These issues are discussed in depth in this paper, with detailed reference to field examples where PWRI has been used, including occasions where scale damage to injection systems occurred. Oxygen and corrosion control are identified as key interactions with scale management. As well as a comparison of scale control in production and PWRI wells, this paper will present a strategy for identifying and managing the scale risk in PWRI wells.
Resistance of nitrifiers inhabiting activated sludge to ciliate grazing
Authors: Pajdak-Stós Agnieszka , Fiałkowska Edyta , Fyda Janusz , Babko Roman
Published: February 2010

We monitored the succession of nitrifiers in a ne.wly opened wastewater treatment plant for five weeks. After the first distinct decrease in total nitrogen, we began monitoring the appearance, size and number of nitrifying bacteria colonies using the fluorescence in situ hybridization (FISH) method. Ammonia oxidizing bacteria (AOB) colonies were visualized under green excitation as red, and nitrite oxidizing bacteria (NOB) colonies were visualized under blue excitation as green. The changes in protozoan community were monitored simultaneously. Ciliates were divided into four functional groups: predatory, bacterivorous free-swimming, bacterivorous crawling, and sessile. The results showed that at the time of the first distinct total nitrogen decrease, the mean length of both AOB and NOB were relatively low, but the colonies, especially those of nitrite oxidizers, were abundant. In time, the distribution of ammonia oxidizer colonies shifted towards larger sizes, but their quantity decreased. In the case of nitrite oxidizers, a similar trend was noticeable but less pronounced. These changes corresponded with an increasing number of crawling bacterivorous ciliates dominated by the “scavenger” genus Aspidisca. The increasing size of nitrifier colonies may have been due to the growing grazing pressure from crawling bacterivorous ciliates. The strong grazing pressure did not negatively affect N-NH4+ removal effectiveness.
Nitrification potential in waste stabilisation ponds: comparison of a secondary and tertiary pond system
Authors: Yamamoto A. , Short M. D. , van den Akker B. , Cromar N. J. , Fallowfield H. J.
Published: February 2010

This study compared the nitrification potential of two separate Waste Stabilisation Ponds (WSPs) operating under differing physical and chemical conditions. In order to probe the nitrification potential of each system, the oxidation of ammonium and also the intermediate product nitrite was assessed using both in situ and laboratory micro-scale incubations. The role of sediment in determining the nitrification potential of the two WSPs was also investigated. Results from laboratory microcosm incubations revealed a competent and strikingly similar nitrification potential for both WSPs in spite of their differing nitrogen and organic loadings, and also suggested a significant role for sediment in WSP nitrogen cycling. Results from in situ field experiments identified biomass uptake to be the dominant nitrogen removal mechanism in natural pond environments. Other aspects of WSP nitrogen cycling are also discussed.
Tax and Subsidy Combinations for the Control of Car Pollution
Authors: Fullerton Don , West Sarah E
Published: February 2010

Despite technological advances, an individual car's emissions still cannot be measured reliably enough to impose a Pigovian tax. This paper explores alternative market incentives that could be used instead. We solve for second-best combinations of uniform taxes on gasoline, engine size, and vehicle age. For 1,261 individuals and cars in the 1994 Consumer Expenditure Survey, we record the car's model, year, and number of cylinders. We then seek a corresponding car in data from the California Air Resources Board that shows the car's engine size, fuel efficiency, and emissions per mile. We calculate the welfare improvement from a zero-tax scenario to the ideal Pigovian tax, and we find that 71 percent of that gain can be achieved by the second-best combination of taxes on gas, size, and vintage. A gas tax alone attains 62 percent of that gain. These results are robust to variation in the elasticity of substitution among goods.
Magnetohydrodynamic flows as Newtonian-type gravitational motions
Authors: Spyrou Nikolaos , Tsagas Christos
Published: February 2010

We study the motion of a magnetised, highly conductive fluid within the framework of Newtonian gravity. Our analysis examines whether and under what conditions magnetohydrodynamic flows can be represented as hydrodynamic ones and then as Newtonian-type gravitational motions. In the latter case we define a generalised effective density and an effective Poisson-type potential, which include the magnetic input and determine the dynamics of the magnetised system. Introducing the dynamical equivalence of the aforementioned two representations, we use it to test mass measurements based on purely gravitational motions. We also provide the generalised Raychaudhuri equation corresponding to the aforementioned effective potential and discuss its implications for the kinematics of the fluid.
Numerical investigation of heat transfer augmentation through geometrical optimization of vortex generators
Authors: Gorji Mofid , Mirgolbabaei Hessam , Barari Amin , Domairry Ganji
Published: February 2010

In this paper a two-dimensional numerical simulation of a steady incompressible and turbulent model has been carried out to study the effects of vortex generators in a compact heat exchanger in a curvilinear coordinate system. The mesh which is applied in this study is boundary fitted and has been smoothed by a Laplace operator. Experimental data of a former study has been applied to validate the numerical results. The effects of geometrical variation are studied by adjusting vortex generators’ inclination and relative cross location. The major issue of this study is the optimal trade-off by selecting an optimal geometric, considering the opposite influences of geometrical variation on Nusselt number and pressure drop.
In vitro synergistic anti-prion effect of cholesterol ester modulators in combination with chlorpromazine and quinacrine
Authors: Orrù Christina , Cannas M. , Vascellari Sarah , Angius Fabrizio , Cocco Pier , Norfo Claudia , Mandas Antonella , La Colla Paolo , Diaz Giacomo , Dessì Sandra , Pani Alessandra
Published: February 2010

Our studies on the role of cholesterol in prion infection/replication showed that brains and peripheral cells of sheep susceptible-to or suffering-from Scrapie were characterized by an altered cholesterol homeostasis, and that drugs affecting cholesterol ester pool were endowed with selective anti-prion activity in N2a cell lines infected with the 22L and RML prion strains. In these prion-infected N2a cell lines, we now report increased anti-prion activity of dual-drug combinations consisting of cholesterol ester modulators associated with prion inhibitors. Synergism was obtained with the cholesterol ester modulators everolimus, pioglitazone, progesterone, and verapamil associated with the anti-prion chlorpromazine, and with everolimus and pioglitazone associated with the anti-prion quinacrine. In addition, comparative lipid analyses in prion-infected vs. uninfected N2a cells, demonstrated a derangement of type and distribution of cholesterol ester, free cholesterol, and triglyceride pools in the infected cells. Single-drug treatments differently affected synthesis of the various lipid forms, whereas combined drug treatments appeared to restore a lipid profile similar to that of the untreated-uninfected cells. We conclude that the anti-prion synergistic effects of cholesterol ester modulators associated with the cholesterol-interfering anti-prion drugs chlorpromazine and quinacrine may arise from the ability of combined drugs to re-establish lipid homeostasis in the prion-infected cells. Overall, these data suggest that inhibition of prion replication can be readily potentiated by combinatorial drug treatments and that steps of cholesterol/cholesterol ester metabolism may represent suitable targets.
Enhancement of tyrosine hydroxylase expression by Cordyceps militaris
Authors: Sapkota Kumar , Kim Seung , Park Young , Choi Bong-Suk , Park Se-Eun , Kim Sung-Jun
Published: February 2010

Cordyceps militaris is a popular medicinal mushroom, and has received extensive attention for medical application because of its various physiological activities. However, there is limited information about the function of Cordyceps militaris on dopaminergic system. This study has attempted to evaluate the effect of cultured fruiting bodies of Cordyceps militaris extract (CME) on the expression of the tyrosine hydroxylase (TH) gene in PC12 cells and rat brain and stomach. Related mRNA levels were determined by the RT-PCR. Protein levels were measured by Western blot and immunohistochemistry. Our results demonstrated CME induced TH gene expression both in vitro and in vivo. Treatment of 10 µg/ml and 20 mg/kg CME to PC12 cells and rat cells yielded significant increases of TH protein levels. Significantly, TH immunoreactive neurons were detected not only in the brain but also in the stomach. TH-immunohistochemical staining was markedly enhanced in animals treated with CME compared to those in the untreated control. These results suggest that CME can upregulate the dopaminergic (DArgic) system, and may contribute to neuroprotection in neurodegenerative diseases.
Essential oil composition of two yarrow taxonomic forms
Authors: Judzentiene Asta , Mockute Danute
Published: February 2010

Differences in essential oil composition of wild Achillea millefolium L., collected at five habitats in Lithuania, where plants with pink (f. rosea) and white (f. millefolium) flowers grow together, were reported. For the first time, oils of different plant organs (inflorescences and leaves) of both forms from every population were analysed in detail. Chemical analysis was performed by GC and GC-MS. The most predominant constituents of the oils were nerolidol (9.4–31.9%, in 11 out of 20 samples), caryophyllene oxide (8.4–23.0%, 4 leaf oils), ß-pinene (8.0–15.2%, 2 samples), eudesmol (11.8–15.8%, 2 leaf oils) and 1,8-cineole (11.9%, one inflorescence oil). Domination of nerolidol was mostly characteristic of A. millefolium f. rosea essential oils (in 8 out of 10 oils). The inflorescences biosynthesised markedly larger amounts of nerolidol and ß-pinene than those of the leaves. An opposite correlation was observed for caryophyllene oxide and eudesmol. Chamazulene (≤2.7%) was determined only in six oils. The 65 identified constituents made up 75.4–96.5% of the oils.
Influence of reproductive status on the daily rhythms of oxidative stress markers in Ovis aries
Authors: Piccione Giuseppe , Giannetto Claudia , Fazio Francesco , Assenza Anna , Caola Giovanni
Published: February 2010

Changes in circadian rhythms of dROMs, Oxy-ads and SHp during reproductive stages were studied in Comisana ewes. Twelve ewes were divided in two equal groups. The experimental group consisted of ewes undergoing gestation and lactation following artificial insemination and the control group consisted of non-pregnant ewes. Blood samples were collected every 3 h over a 24 h period, 20 days before insemination, on days 100 and 140 of pregnancy, on days 10, 30 and 200 post-partum and during the dry period. In the control group, blood samples were collected on the same days and with the same procedures as those used for the experimental group. A significant effect of time on all parameters studied was observed in the experimental group. Daily rhythms of the parameters studied were observed in the control group in all experimental conditions, and in the experimental group during pre-pregnancy and dry periods. We conclude that the reproductive status of sheep affects oxidative stress markers in blood and their circadian rhythms.
Limit Elements in the Conﬁguration Algebra for a Cancellative Monoid
Authors: Saito Kyoji
Published: February 2010

Associated with the Cayley graph

(Γ, G)

of a cancellative monoid

Γ

with a ﬁnite generating system

G

, we introduce two compact spaces:

Ω(Γ, G)

consisting of pre-partition functions and

Ω(P_{Γ,G})

consisting of series opposite to the growth function

P_{Γ,G}(t) := \sum^∞ _{n=0}\#Γ_n · t^n

(where

Γ_n

is the ball of radius

n

centered at the unit element in the Cayley graph). Under mild assumptions on

(Γ, G)

, we introduce a ﬁbration

π : Ω(Γ, G) → Ω(P_{Γ,G})

, which is equivariant with respect to a

(\tilde τ, τ)

-action. The action is transitive if it is of ﬁnite order. Then we express the ﬁnite sum of the pre-partition functions in each ﬁber of

π

as a linear combination of the ratios of the residues of the two growth functions

P_{Γ,G}(t)

and

P_{Γ,G}\mathcal M(t) := \sum^∞ {n=0}\mathcal M(Γ_n)t^n

(where

\mathcal M(Γ_n)/\#Γ_n

is the free energy of the ball

Γ_n

) at the poles on the circle of their convergence radius.
Denseness of Norm-Attaining Mappings on Banach Spaces
Authors: Choi Yun Sung , Lee Han Ju , Song Hyun Gwi
Published: February 2010

Let

X

and

Y

be Banach spaces. Let

P({}^nX : Y)

be the space of all

Y

-valued continuous

n

-homogeneous polynomials on

X

. We show that the set of all norm-attaining elements is dense in

P({}^nX : Y)

when a set of u.s.e. points of the unit ball

B_X

is dense in the unit sphere

S_X

. Applying strong peak points instead of u.s.e. points, we generalize this result to a closed subspace of

C_b(M, Y)

, where

M

is a complete metric space. For complex Banach spaces

X

and

Y

, let

A_b(B_X : Y)

be the Banach space of all bounded continuous

Y

-valued mappings

f

on

B_X

whose restrictions

f|_{B_X^\circ}

to the open unit ball are holomorphic. It follows that the set of all norm-attaining elements is dense in

A_b(B_X : Y)

if the set of all strong peak points in

A_b(B_X)

is a norming subset for

A_b(B_X)

.
Thom Polynomials and Schur Functions: The Singularities $A_3(−)$
Authors: Lascoux Alain , Pragacz Piotr
Published: February 2010

Combining the “method of restriction equations” of Rimányi et al. with the techniques of symmetric functions, we establish the Schur function expansions of the Thom polynomials for the Morin singularities

A_3 : (\mathbf C^•, 0) → (\mathbf C^{•+k}, 0)

for any nonnegative integer

k

.
Dominated Bilinear Forms and 2-homogeneous Polynomials
Authors: Botelho Geraldo , Pellegrino Daniel , Rueda Pilar
Published: February 2010

The main goal of this note is to establish a connection between the cotype of the Banach space

X

and the parameters

r

for which every 2-homogeneous polynomial on

X

is

r

-dominated. Let

\mathrm{cot} X

be the inﬁmum of the cotypes assumed by

X

and

(\mathrm{cot} X)^*

be its conjugate. The main result of this note asserts that if

\mathrm{cot} X > 2

, then for every

1 ≤ r < (\mathrm{cot} X)^*

there exists a non-

r

-dominated 2-homogeneous polynomial on

X

.
A Characterization of Stein Completion of 0-normal Coronae
Authors: Vâjâitu Viorel
Published: February 2010

We show that a 0-normal complex space
X
that is a corona admits a Stein completion if and only if _H_1 (
X
,
O
) is separated.
Rice pads: Novel devices for homogeneous fat suppression in the knee
Authors: Moriya Susumu , Miki Yukio , Yokobayashi Tsuneo , Kanagaki Mitsunori , Komori Yoshiaki , Ishikawa Mitsunori
Published: February 2010

Background: In magnetic resonance imaging (MRI) of the knee joint, when imaging the knee in a flexed position using the chemical-shift-selective (CHESS) method, lingering fat signals in the popliteal region are sometimes seen.

Purpose: To investigate whether a pad filled with rice (rice pad) placed in the popliteal space is effective in eliminating the lingering fat signals in MR images of the flexed knee, based on the hypothesis that the use of a rice pad would improve the fat suppression effect.

Material and Methods: Subjects were 10 healthy volunteers (five males, five females; age, 20–45 years) from whom images were taken using CHESS. Images were obtained with: 1) the knee extended and nothing placed underneath; 2) the knee bent with a sponge placed underneath; and 3) the knee bent with a rice pad placed underneath. The effectiveness of suppressing fat signals was visually assessed by one radiologist and one radiological technologist.

Results: The fat suppression effect in images obtained with the knee extended was good. In contrast, the images made with a sponge under the knee had conspicuous lingering fat signals for nearly all subjects. In the images made with a rice pad under the knee, a uniformly good fat signal suppression effect was seen in all patients, and the assessment score was far higher than that with the sponge pillow ( P<0.001).

Conclusion: Lingering fat signals were suppressed with the use of a rice pad, and fat-suppressed images of the knee joint using CHESS were found to be improved.
Assessment of hip dysplasia and osteoarthritis: Variability of different methods
Authors: Troelsen Anders , Rømer Lone , Kring Søren , Elmengaard Brian , Søballe Kjeld
Published: February 2010

Background: Reliable assessment of hip dysplasia and osteoarthritis is crucial in young adults who may benefit from joint-preserving surgery.

Purpose: To investigate the variability of different methods for diagnostic assessment of hip dysplasia and osteoarthritis.

Material and Methods: By each of four observers, two assessments were done by vision and two by angle construction. For both methods, the intra- and interobserver variability of center-edge and acetabular index angle assessment were analyzed. The observers’ ability to diagnose hip dysplasia and osteoarthritis were assessed. All measures were compared to those made on computed tomography scan.

Results: Intra- and interobserver variability of angle assessment was less when angles were drawn compared with assessment by vision, and the observers’ ability to diagnose hip dysplasia improved when angles were drawn. Assessment of osteoarthritis in general showed poor agreement with findings on computed tomography scan.

Conclusion: We recommend that angles always should be drawn for assessment of hip dysplasia on pelvic radiographs. Given the inherent variability of diagnostic assessment of hip dysplasia, a computed tomography scan could be considered in patients with relevant hip symptoms and a center-edge angle between 20° and 30°. Osteoarthritis should be assessed by measuring the joint space width or by classifying the Tönnis grade as either 0–1 or 2–3.
Use of noun morphology by children with language impairment: the case of Hungarian
Authors: Lukács Ágnes , Leonard Laurence B. , Kas Bence
Published: February 2010

Background: Children with language impairment often exhibit significant difficulty in the use of grammatical morphology. Although English‐speaking children with language impairment have special difficulties with verb morphology, noun morphology can also be problematic in languages of a different typology.

Aims: Hungarian is an agglutinating language with multiple suffixation, in which both regular‐class and irregular‐class nouns contain the same recognizable grammatical markers, but the two classes differ in their morphophonology and productivity. Such typological characteristics provide a good basis for evaluating processing accounts of language impairment such as the morphological richness account.

Methods & Procedures: We examined the production of Hungarian irregular and regular noun morphology through elicited production of nouns with plural, accusative case and plural plus accusative case suffixes in an older (8–10 years) and a younger (4–7 years) group of children with language impairment and two verbal control groups matched on vocabulary size. The children's accuracy was scored both in terms of grammatical function (whether plural and/or accusative case was appropriately marked) and morphophonology (whether the production reflected the phonotactic form required for the stem plus suffix).

Outcomes & Results: The younger children with language impairment were less accurate than the younger verbal control children when two suffixes (marking plural and accusative case) were required, at least when noun stem classes were regular. All groups showed significant overgeneralization of stem forms with correct selection of suffixes. However, there were strong word frequency effects in the language impairment, but not in the verbal control groups.

Conclusions & Implications: Much of the data were consistent with predictions of the morphological richness account. However, there was also evidence suggestive of differences between the language impairment and verbal control groups in their representations. In particular, the children with language impairment seemed to rely more (though not exclusively) on memorized items in the lexicon.
Communicative and linguistic development in preterm children: a longitudinal study from 12 to 24 months
Authors: Cattani Allegra , Bonifacio Serena , Fertz Mariacristina , Iverson Jana M. , Zocconi Elisabetta , Caselli M. Cristina
Published: February 2010

Background: Research conducted on preterm children's linguistic skills has provided varying pictures, and the question of whether and to what extent preterm children are delayed in early language acquisition remains largely unresolved.

Aims: To examine communicative and linguistic development during the second year in a group of Italian children born prematurely using the ‘Primo Vocabolario del Bambino’ (PVB), the Italian version of the MacArthur–Bates Communicative Development Inventory. The primary goal was to compare action/gesture production, word comprehension, and word production, and the relationship between these three domains in preterm children and to normative data obtained from a large sample of Italian children born at term. A second aim was to address the longstanding debate regarding the use of chronological versus corrected gestational age in the assessment of preterm children's abilities.

Methods & Procedures: Parents of twelve preterm children completed the PVB questionnaire at five age points during the children's second year, and scores were compared with those from a normative sample of full‐term children and those of 59 full‐term children selected as a control group from the normative sample for the PVB.

Outcomes & Results: Preterm children exhibited a delay in all three aspects of communication and language. In particular, communicative–linguistic age tended to lag approximately 3 months behind chronological age when children were between the ages of 12 and 24 months. When chronological age was used, preterm children's percentile scores for all three components of communication and language fell within the lower limits of the normal range, while scores calculated using corrected age either fell at or above the 50th percentile.

Conclusions & Implications: Findings suggest that despite the significant biological risk engendered by premature birth, early communicative and linguistic development appears to proceed in a relatively robust fashion among preterm children, with tight relations across communicative domains as in full‐term children. Employing both chronological and corrected gestational age criteria in the evaluation of preterm children's abilities may provide important information about their progress in language acquisition. This may be especially important during the initial stages of communicative and linguistic development, inasmuch as comparisons of the two sets of scores may provide clinicians with a way to distinguish children who may be at risk for language problems from those who may be expected to progress normally.
Speech and language therapy in Sure Start Local Programmes: a survey‐based analysis of practice and innovation
Authors: Fuller Alison
Published: February 2010

Background: Sure Start has been a flagship policy for the UK Labour Government since 1998. Its aim was to improve the life chances of children under five years of age who live in areas of socio‐economic disadvantage by means of multi‐agency, multidisciplinary Sure Start Local Programmes (SSLPs). Speech and language therapists have played a key part in many SSLPs, and have had the opportunity to extend their roles. Despite the scrutiny paid to Sure Start, there has been no comprehensive analysis of speech and language therapists' contribution to date. Studies have focused on individual programmes or small samples: there has been no attempt to collate the full range of practice. As Sure Start evolved and Children's Centres emerged, it became vital to learn from the Sure Start experience and inform the mainstreaming of practice, before the window of opportunity closed.

Aims: The survey aims were, firstly, to identify the range of practice amongst speech and language therapists working in SSLPs, highlighting new practice, and, secondly, to categorize the practices according to the tiered model of UK health and social services of the Royal College of Speech and Language Therapists (RCSLT 2006).

Methods & Procedures: An online mixed‐method, semi‐structured survey was designed to elicit primarily quantitative and categorical data. A total of 501 Sure Start Local Programmes were invited to take part. A total of 128 speech and language therapists responded, giving a response rate of 26%. A descriptive analysis of the response data was undertaken.

Outcomes & Results: A total of 103 respondents (80%) reported maintaining a clinical role as well as extending their roles to include preventative services. Of those 103 respondents, 69% were able to see referred children at a younger average age and 80% saw them more quickly than before Sure Start. A wide variety of preventative practice was identified. A widening of access to speech and language therapist was reported in terms of venues used and hours offered. Respondents reported on their use of evaluation or outcome measures, which was at a higher rate for new practice than for established practice. A total of 121 respondents (95%) reported at least one example of new practice; 103 (80%) reported at least one use of evaluation or outcome measures. The tiered model of UK health and social services provided an effective way of categorizing practice.

Conclusions & Implications: A categorized record of Sure Start speech and language therapist is presented that may contribute to establishing a broad curriculum of practice for speech and language therapist in the early years. The effectiveness of the practices is not investigated: suggestions are made for further research to develop the evidence base.
Aphasia and text writing
Authors: Behrns Ingrid , Ahlsén Elisabeth , Wengelin Åsa
Published: February 2010

Background: Good writing skills are needed in almost every aspect of life today, and there is a growing interest in research into acquired writing difficulties. Most of the findings reported so far, however, are based on words produced in isolation. The present study deals with the production of entire texts.

Aims: The aim was to characterize written narratives produced by a group of participants with aphasia.

Methods & Procedures: Eight persons aged 28–63 years with aphasia took part in the study. They were compared with a reference group consisting of ten participants aged 21–30 years. All participants were asked to write a personal narrative titled ‘I have never been so afraid’ and to perform a picture‐based story‐generation task called the ‘Frog Story’. The texts were written on a computer.

Outcome & Results: The group could be divided into participants with low, moderate, and high general performance, respectively. The texts written by the participants in the group with moderate and high writing performance had comparatively good narrative structure despite indications of difficulties on other linguistic levels.

Conclusions & Implications: Aphasia appeared to influence text writing on different linguistic levels. The impact on overall structure and coherence was in line with earlier findings from the analysis of spoken and written discourse and the implication of this is that the written modality should also be included in language rehabilitation.
Legal decision‐making by people with aphasia: critical incidents for speech pathologists
Authors: Ferguson Alison , Duffield Gemma , Worrall Linda
Published: February 2010

Background: The assessment and management of a person with aphasia for whom decision‐making capacity is queried represents a highly complex clinical issue. In addition, there are few published guidelines and even fewer published accounts of empirical research to assist.

Aims: The research presented in this paper aimed to identify the main issues for speech pathologists when decision‐making capacity for legal and related matters arose for their clients with aphasia, and to describe qualitatively the nature of these issues and the practices of the speech pathologists in these situations.

Methods: & Procedures: The methodology was informed by the qualitative research paradigm and made use of the semi‐structured interview methods developed for the Critical Incident Technique. Nine speech pathologists, with a range of clinical experience between three and 27 years, were interviewed by telephone, with verbatim notes being taken on‐line by the interviewer. The speech pathologists described a total of 21 clients (15 male, six female) with acquired neurological communication disorders (including cerebral vascular accident, traumatic brain injury, and tumour) whose care had raised critical incidents for the speech pathologist in relation to legal and related matters. These verbatim notes were qualitatively analysed using NVivo qualitative analysis software.

Outcomes & Results: The main incidents related to legal decisions (for example, power of attorney, will‐making), as well as decisions involving consent for medical treatment, discharge, accommodation, and business/financial decisions. In all but one of the incidents recounted, the issues centred on a situation of conflict between the person with aphasia and their family, friends or with the multidisciplinary team. The roles taken by the speech pathologists ranged from those expected within a speech pathology scope of practice, such as that of assessor and consultant, to those which arguably present dilemmas and conflict of interest, for example, interpreter, advocate. The assessment practices involved some standardized testing, but this was stressed by all participants to be of lesser importance than informal observations of function. Speech pathologists emphasized the importance of multiple observations, and multimodal means of communication.

Conclusions: & Implications: The findings indicate that speech pathologists are currently playing an active role when questions arise regarding capacity for legal and related decision‐making by people with aphasia. At the same time, the findings support the need for further research to develop guidelines for practice and to build educational experiences for students and novice clinicians to assist them when they engage with the complex case management issues in this area.
Effect of Plant Residues on AM Fungi
Authors: Vaidya Geeta Shrestha , Shrestha K , Wallander H
Published: February 2010

In this study we have investigated the effect of organic matter on growth of an arbuscular mycorrhizal (AM) fungi in eroded slopes in Nepal such as Forest in Kavre District. Different types of organic matter (leaves of Thitonia diversifolia, Eupatorium adenophorum, Lantana camara, farm compost) and tri-superphosphate were mixed with eroded soil. The mesh bags were buried around trees of eroded site. The mesh bags were harvested after 6 months and the AM fungi in the mesh bags was quantified by analysing the AM spores. Key words: Organic matters; Arbuscular mycorrhizal fungi; Fertilizers and forest. DOI: 10.3126/sw.v6i6.2640 Scientific World, Vol. 6, No. 6, July 2008 85-88
Effect of spindle speed on textile properties and productivity of fine jute yarn
Authors: Miazi Md Osman Ghani , Mahabubuzzaman AKM , Kabir Md Mazedul
Published: February 2010

Spindle speed is an important parameter for the production of jute yarn [1]. An Apron Draft spinning frame was modified in to ring system by incorporating rings and travelers instead of flyers. The experiments were performed for investigating the effect of spindle speed on textile properties and productivity of jute yarn of 103 tex. The spindle speed was varied from 5000 rpm to 9000 rpm. The experiments were performed with Bangla White B (BWB) grade jute sliver of finisher drawing of linear density 2415 tex (70 lb/spy). The draft ratio and the twist used in the experiments were 23 and 240 tpm (turns per meter) respectively. The ring size was KW (4) 76 mm Ø. Steel travelers number 1, Type G, semicircular in shape were used in the experiment. Ten runs were performed for the experiment at the standard atmospheric condition, 20 ± 2°C, and relative humidity 65% ± 2%. The nominal count of the yarn produced was 103 tex. The yarns produced through the experiments were tested for different textile properties. Analysis of the test results shows that the spindle speed greatly influences the textile properties, such as strength, elongation, yarn breakage, productivity, quality ratio etc. of produced yarn. In consideration of the productivity, quality and other textile properties of the yarn, the optimum spindle speed was determined for the production of fine jute yarn of 103 tex. Key Words: Apron draft, spindle speed, fine jute yarn. DOI: 10.3329/diujst.v4i2.4358 Daffodil International University Journal of Science and Technology Vol.4(2) 2009 pp.1-5
Volumetric and viscometric studies on electrolytes in non-aqueous solvent
Authors: Yousuf MA , Reza KM Salim , Moniruzzaman Md , Aziz MA , Salam MA
Published: February 2010

The densities, ρ and viscosities, η of NH4Cl, NiCl2 and FeCl3 in dimethylsulfoxide were studied as a function of concentration. The partial molal volume, (φ0v) of these electrolytes were evaluated. The viscosity and viscosity-coefficients (A and B) were also determined by Jones-Dole equation. B-coefficient for NiCl2 and FeCl3 are positive that show structure making behavior in all the solutions while those of NH4Cl are negative indicating structure breaking properties. The coefficient A represents the solute-solute interactions coupled with size and shape effect of the solute and to some extent solute-solvent interactions. The behaviors of three solutes in binary systems were discussed in terms of the charge, size and hydrogen bonding effect. Keywords: Density, Apparent and partial molal volume, viscosity coefficient. DOI: 10.3329/diujst.v4i2.4360 Daffodil International University Journal of Science and Technology Vol.4(2) 2009 pp.15-18