bluuebunny/crossref_metadata_2025 huggingface dataset:
Creep of a Composite Box Beam with Design Implications
Authors: Hoa S. V.
Published: July 2017

A box beam made of fiber glass reinforced vinyl ester was subjected to static loading over a period of three months. Four point bending was used. Three different loads were examined, each load was applied for a period of one month. Displacement at the center of the beam and strain gage values were recorded. The results show that creep is significant during the first month of initial loading. During the subsequent two months, even though the loads were larger which resulted in larger elastic strains, creep rates are smaller. A design exercise is carried out to demonstrate the feasibility in using fiber reinforced composites for making structural elements for building applications.
Mechanical Characterization of Hybridized Braided Composite Structures
Authors: Powell Robert E. , Yeh Hsien-Yang
Published: July 2017

An analytic model has been created which combines strength of Materials Micromechanic Theory and Laminate Plate Theory to estimate the mechanical properties of two hybrid braided architectures. These results are compared with test data to derive empirical "knockdown" factors which result from fiber crimping and jamming during the braiding process. Knockdown Factors are derived from E.., Ey, and G.,. In addition, the estimated coefficients of thermal expansion and Poisson's Ratio are compared with test data. By quantifying the empirical Knockdown Factors, more representative material properties can be utilized in engineering analysis for hybrid braided materials.
Geometrically Non-Linear Transient Dynamic Response of Laminated Composite Stiffened Shells
Authors: Goswami Sanjib , Mukhopadhyay Madhujit
Published: July 2017

The paper uses the conventional 9-noded Lagrangian element for studying geometrically non-linear elastic transient response analysis of composite stiffened shell. An improved version of the stiffener modelling has been used in which a stiffener can be placed anywhere inside the element. For the first time in the literature, concentric or eccentric stiffeners has been used for composite stiffened shells for solving the problem of the paper which is not available in any existing commercial packages. Large deflection transient response analysis of composite stiffened shells has also been presented for the first time. The results of stiffened composite cylindrical shells and doubly curved shells with different boundary conditions and various laminae orientations have been presented for eccentric stiffeners. Parametric studies considering different variables have also been carried out.
Static Analysis of Laminated Shells Using a Refined Shear Deformation Theory
Authors: He Ji-Fan
Published: July 2017

In this paper the refinement of a previously published discrete-layer shear deformation laminated shell theory by the assumption that the transverse shear strains across any two layers are linearly dependent on each other is briefly described. The theory contains the same dependent variables as first-order shear deformation theory, but the set of governing differential equations is of the twelfth order. No shear correction factors are required. Solutions for a complete cylindrical shell and two shallow shells are obtained. The numerical results are compared with classical lamination theory, first-order shear deformation theory and two higher-order shear deformation theory solutions.
Numerical and Experimental Study on the Edge Effect of Resin Transfer Molding
Authors: Wu Ching-Jenn , Hourng Lih-Wu , Liao Jyh-Chin
Published: July 2017

The correlation of the porosity and the permeability, based on the experimental data, for the TGFM-300 P/E random fiber mat is proposed in the present work. The edge effect is simulated by the creeping motion of the resin with permeable boundary condition along the edge of the fiber mats. Results show that the edge effect is very sensitive to the shape of the fiber mat. Numerical predictions agree with experimental results, when the fiber mat is well shaped. The edge effect is negligible as the dimension of the fiber mat is slightly larger than that of the mold cavity. The present paper combines the body-fitted FDM and the FEM to deduce an auto-meshed and auto-node-element relating numerical scheme. This scheme is convenient and effective in solving the moving boundary problems with irregularly geometric boundaries, such as the filling process of RTM. The difference between the elliptic type body-fitted FDM and the FEM are compared and discussed in detail.
Antisymmetric Bending Analysis of Symmetric Sandwich Plates Including Transverse Shear and Normal Effects
Authors: He Ji-Fan
Published: July 2017

Antisymmetric bending analysis of sandwich plates with symmetric and balanced laminated faces and an orthotropic core is presented here. The transverse shear and normal strain and stress effects on bending of such sandwich plates are considered. A set of twelfth-order governing equations and consistent boundary conditions are given from a mixed variational theorem. The response of square sandwich plates with fully simple supports subjected to transverse sinusoidal loading is evaluated. The numerical results are compared with elasticity solutions and results obtained from other theories. The present theory is found to agree closely with three-dimensional elasticity solutions.
Notched Strength and Effective Crack Growth in Woven Fabric Composite Laminates with Circular Holes
Authors: Afaghi-Khati Akbar , Ye Lin
Published: July 2017

The effective crack growth model (ECGM) is extended to evaluate the residual strength of woven fabric composite laminates with circular holes. It is assumed that when the local normal stress reaches the tensile strength of the unnotched laminate, damage initiates and propagates with increase of the applied load. The damage is then modelled by a fictitious crack with cohesive stress acting on the crack surfaces. The damage growth is simulated by extension of the fictitious crack step by step and reduction of the cohesive stress with crack opening. The apparent fracture energy (G*) is used to define the relationship between the unnotched strength and the critical crack opening. Based on the equilibrium condition, an iterative technique is applied to evaluate the applied load required to produce the damage growth. The residual strength of notched composite laminates is defined by the unstable point of the applied load with damage growth. The residual strength of notched woven fibric carbon/epoxy, glass/epoxy and glass/ polyester composite laminates were evaluated with various hole diameters and specimen widths. Effect of specimen geometry on the critical damage zone size was discussed. The simulations from the effective crack growth model correlate well with the experimental data in open literature.
Environmental Effects on Stitched RTM Textile Composites
Authors: Furrow Keith W. , Loos Alfred C. , Cano Robert J.
Published: July 2017

The effects of temperature and humidity cycling on mechanical properties of AS4/3501-6 quasi-isotropic textile composites were determined. The composites were resin transfer molded from unstitched, Kevlar 29 stitched, and S-2 glass stitched uniweave fabric preforms. Data presented include photomicrographs, compression strengths and compression-compression fatigue results for environmentally cycled and uncycled composites. After manufacture, microcracks developed around the glass and Kevlar stitching. These microcracks did not grow after environmental cycling. The unstitched material developed microcracks only after cycling. Temperature and humidity cycling reduced the static compression strength of the unstitched and Kevlar stitched uniweave materials nearly 10 percent. Under the same conditions the glass stitched uniweave material lost 3 percent of its baseline strength. Combined temperature and humidity cycling did not affect the fatigue properties of the uniweave materials when the test specimens were dried to their original weights before testing. Temperature cycling at constant 40 percent humidity, resulted in a 5 percent decrease in static compression strength for the unstitched and Kevlar stitched material. Unstitched, glass stitched and Kevlar stitched materials exposed to constant 60°C and 95 percent relative humidity for 80 days and then saturated in 70'C water, lost 17, 7 and 19 percent of their baseline compression strength, respectively. These conditions lowered the fatigue strengths only after saturation. Braided composites including, a stitched 2-D braid, an unstitched 2-D braid and a 3-D braid were also exposed to environmental cycling. The moisture absorption in the AS4/E905L system was lower than the AS4/3501-6 system. Consequently environmental cycling had little effect on the static or fatigue strengths of braided materials.
Ceramic Coatings on Polymers by High Energy Beam for Tribology Application
Authors: Ayrault S. , Chabert B. , Soulier J. P. , Treheux D. , Vannes A. B. , Chevallier P.
Published: July 2017

Aluminium oxide powder has been deposited on a thermoplastic polymer (PET) using atmospheric plasma and laser (CO2, λ = 10.6 μm). The results have shown that there exists a mechanical anchorage of ceramic on the surface of the polymer whatever the technique used with different ceramic structures. To characterize the ceramic coating, two techniques have been used by tribological solicitation with little displacement (fretting) and by erosion. In this case, ceramic influence on the surface has been noted like protective substance in addition to the polymer structure interaction.
Experimental Study and Simple Failure Analysis of Stitched J-Stiffened Composite Shear Panels
Authors: Yeh Hsien-Yang , Chen Victor L.
Published: July 2017

Two fuselage type, stitched composite shear panels with J-shape stiffeners manufactured through the process of Resin Transfer Molding technique were tested. Through the diagonal tension tests, it was found that failure of each panel occurred at approximately 3.5 times its initial buckling load, indicating significant diagonal tension strength. Neither of the panels failed by stiffener “pop-off,” showing that the stitching helps to inhibit this failure mode. No other damage or delamination of the panel was visible as well.

The newly developed generalized Yeh-Stratton (Y-S) failure criterion was used to evaluate the failure of these composite panels. Compared with several other failure criteria, the calculated failure loads are quite close to experimental results and all are conservative. The Y-S criterion is the most conservative for this case.
Water Intrusion in Graphite/Epoxy Sandwich Panels Subjected to Low Level Impact Damage
Authors: Yeh Hsien-Yang , Nelsen Eric B.
Published: July 2017

Due to the increasing use of graphite/epoxy sandwich panels on the exterior surface of aircraft, it is necessary to determine the ability of the panels to resist potential damage caused by runway debris. There have been numerous studies on the abilities of composite panels to resist the damage due to low level impact; however, the ability of an impacted panel to resist water intrusion needs to be studied. Impact by runway debris can damage panels and allow water intrusion to the core of the panels. Water will damage the core and reduce the load carrying capabilities of the panels.

In this paper the theory of impact damage of composite laminates will be applied to graphite/epoxy sandwich panels and the predictions will be compared to experimental results. The panels will be subjected to falling weight impact tests and then tested for water intrusion.
On the Distribution of Particulates in Cast Metal Matrix Composites
Authors: Xiao Keping , Lyons Jed S.
Published: July 2017

This paper is concerned with the reporting of the distribution of particulates in the casts prepared from bulk ingots of metal matrix composites. Based on the actual determination of the volume fraction of particles (VFPs) in two different casts (mold) geometry (L and J shaped), effect of sharp corners and curvatures and the boundaries of the mold on the distribution of particles in the cast has been studied. It is observed that the actual distribution of volume fraction of particles varies quite significantly from one location of the cast to the other, depending on the actual cast geometry. Microhardness values are also measured and found to follow the same pattern of variation as the volume fraction of particles (VFPs).
Property Degradation of Anisotropic Composite Laminates with Matrix Cracking. Part 1: Development of Constitutive Relations for (θm/90n)s Cracked Laminates by Stiffness Partition
Authors: Yu Hua , Xingguo Wang , Zhengneng Li , Qingzhi He
Published: July 2017

The study on property degradation of damaged composite laminates is extended to anisotropic laminates with matrix cracking. In Part 1 of the paper, an idea of “stiffness partition” is proposed to deal with the puzzle that the in-plane normal response is coupled with the shear response of the laminates. For (θ m/90 n), laminates containing transversely cracked layers under general in-plane loading, the constitutive relations are derived and the effective stiffnesses are expressed as the functions of crack density.
A Multiple Percolation Approach to EMI Shielding Composites Incorporating Conductive Fillers
Authors: Olivero D. A. , Radford D. W.
Published: July 2017

Lightweight composites composed of silver coated hollow microspheres in epoxy for shielding of electromagnetic interference (EMI) address the need for mass reduction in aerospace applications for improvement of economy and payload capability. To achieve the structural integrity of fiber reinforced composites, incorporation of microspheres into a woven fiberglass/epoxy composite is evaluated as a method to retain structural and electrical performance. In this approach, the percolation threshold of conductive filler is reduced by a multiple percolation of the matrix phase. Laminate strength is retained in the 0/90° fiber orientation, and only slightly reduced in the ±45° orientation. Shielding effectiveness in excess of 60 dB is obtained at a microsphere volume fraction of only 19%. Conductive short fibers were also employed, with similar mechanical and electrical performance relative to microspheres. An approach is, therefore, presented to optimize both mechanical and electrical composite properties, at a fraction of the mass of bulk metals, and without the durability issues of thin metallic surface coatings.
Numerical Predictions of Progressive Damage Evolution in Particulate Composites
Authors: Kwon Y. W. , Baron D. T.
Published: July 2017

A method is presented for calculating stresses and strains in a loaded particulate composite structure (specimen) as damage initiates and grows. Load is incrementally applied to a numerically simulated specimen. For every load increment, a finite element method model is used to calculate the composite stresses and strains at each point. A micromechanical model uses the composite strains to calculate the stresses and strains in the composite's component materials, the particles and matrix. A damage model uses the matrix strains to determine values for local matrix damage, and to set reductions in the stiffnesses of damaged matrix material regions, each of which is proportional to the associated damage value. At damaged locations, the micromechanical model uses the reduced matrix stiffnesses to calculate reduced composite stiffnesses. All reduced matrix and composite stiffnesses calculated during a load increment are used in the next load increment.

Matrix strain values are set which determine damage initiation, growth, and saturation. Damage saturation indicates matrix material failure, and for saturation the composite stiffness approaches zero. At a specimen point, a matrix crack will form or extend when the point becomes saturated with damage. Numerical simulation predictions are presented, and compared to experimental data. Plots are included showing stress and strain variation, and crack growth.
Interlaminar Thermal Stresses in Polar-Anisotropic Circular Plates
Authors: Tutuncu Naki
Published: July 2017

Stresses and deformations due to a uniform change in temperature in plates of general polar anisotropy are determined. The plate was assumed to be symmetrically laminated, each lamina being oriented at an arbitrary angle with respect to the radial coordinate. Due to unconstrained and stress-free outer boundary of the plate, derivation of a closed-form solution for radial and circumferential displacements was possible. The interlaminar thermal stresses are then calculated and, using the Tsai-Wu tensorial failure theory, the reserve factors for each lamina interface has been determined. The material used for numerical results was chosen arbitrarily for purely illustration purposes. The results have shown that it was preferable, solely for the increased strength purposes, to have circumferentially wound fibers for the particular material and the lay-up chosen.
Effect of Gas Channel Design on Bending Properties of Gas-Assisted Injection Molded Polystyrene Parts
Authors: Chien Rean Der , Chen Shia-Chung , Kang Yuan , Yeh Hsien-Yang
Published: July 2017

Polystyrene (PS) thin plates designed with semicircular gas channel of different radius and with rectangular gas channel of different width to height ratio were gasassisted injection molded (GAIM). Effects of geometrical factors introduced by part thickness, various section shapes and the associated dimensions of gas channels on bending properties of GAIM parts were investigated via a bending test. It was found that gas channel design, introducing additional moment of inertia determined by the geometry of channel section and the hollowed core, results in part structural reinforcement. Bending properties of GAIM parts, including maximum bending load and absorbed bending energy, are enhanced when part thickness and the sizes of semicircular and rectangular gas channel increase. Part stiffness and maximum bending load increases linearly with inertia moment and section modulus of the plate, respectively. Increasing gas channel height has the best effect on the enhancement of bending stiffness. The present investigation provides part designers a guideline for choosing the most effective gas channel design to achieve a specific part bending structural performance.
The Effect of Fibre Orientation and Distribution on the Tooth Stiffness of a Polymer Composite Gear
Authors: Weale D. J. , White J. , Walton D.
Published: July 2017

Polymer composite gears can provide a performance increase over gears made from a plain polymer. However, the moulding process leaves a complex fibre orientation and distribution (FOD) resulting in large variations in material properties. Accurate estimates of material properties are required for detennining load sharing, Hertzian and bending stresses, and for tooth correction. Computational imaging techniques are providing means to determine the FOD in moulded gears. For the first time, these techniques are providing reliable estimates of the elastic constants throughout the gear and have been applied in detail to a 2D finite element model

This paper compares predicted stiffnesses of gear teeth using this detailed technique with stiffnesses predicted by materials suppliers' data and simple rule of mixtures.
A Phenomenological Model for Flow-Induced Crystallization
Authors: Dairanieh I. S. , Mchugh A. J. , Doufas A. K.
Published: July 2017

The Hamiltonian Bracket Formulation combined with the Avrami equation was used to develop a model for the flow-induced crystallization of polymers. The amorphous part of the chain was modeled as a non-linear Hookean dumbbell and the crystalline part as a rigid rod. Evolution equations for the configuration tensors of the two phases and for the degree of crystallinity were obtained and were subsequently solved for the transient and cessation case under different flow conditions. The model has a number of parameters that can be obtained (with the exception of one) from Theological measurements and quiescent crystallization experiments. The model predicts the variation in the degree of crystallinity and the induction time as a function of the polymer properties and the processing conditions. The model can also be used to predict the development of birefringence. The predictions of the model are in general agreement with the experimental observations.
Needed: A Multicultural Perspective for Adult Education Research
Authors: Ross-Gordon Jovita M.
Published: July 2017

Educators have recently taken interest in understanding the needs of racial and ethnic minority youth in the schools. A review of adult education research literature over the last five years suggests the adult education research community has not shown a similar interest. Given the traditional un-derrepresentation of minority adults in adult education programs and considering the changing demographics of the U.S., this omission gives cause for concern. Presented are data revealing the paucity of publications addressing multicultural issues in adult education, despite a small but growing number of dissertations. In an effort to stimulate discussion and research in the area, the author suggests a number of questions worthy of investigation. Methodological issues particularly relevant to research on minority populations are also discussed.
Preparing for Veterans: Higher Education and the Efforts to Accredit the Learning of World War II servicemen and women
Authors: Rose Amy D.
Published: July 2017

In the years following World War II, American colleges and universities experienced unprecedented growth due to the numbers of returning veterans who, aided by the G.I. Bills, flocked to higher education. Administrators at all levels prepared for the new students with great apprehension. They experimented with new formats and approaches which would ease their way. This paper examines the development of testing and evaluation procedures during this period. In particular, it examines some of the assumptions associated with evaluation techniques and the assumptions connected to their widespread acceptance. In addition, it raises questions about the nature of the precedent set by these reforms and their importance to present-day adult education.
Diagnosis of Tuberous Sclerosis Complex
Authors: Roach E. Steve , Sparagana Steven P.
Published: July 2017

Tuberous sclerosis complex is a dominantly inherited disorder affecting multiple organs; because of its phenotypic variability, the diagnosis of tuberous sclerosis complex can be difficult in the young or in individuals with subtle findings. Recently revised consensus diagnostic criteria for tuberous sclerosis complex reflect an improved understanding of its clinical manifestations and its genetic and molecular mechanisms. The diagnostic criteria are based on the premise that there are probably no truly pathognomonic clinical signs for tuberous sclerosis complex; signs that were once regarded as specific occur as isolated findings in individuals with no other clinical or genetic evidence of tuberous sclerosis complex. Consequently, the revised criteria require tuberous sclerosis complex—associated lesions of two or more organ systems or at least two dissimilar lesions of the same organ to confirm the diagnosis. The addition of DNA testing complements clinical diagnosis and allows more precise genetic counseling and, in some individuals, prenatal diagnosis. Nevertheless, the 15% false-negative rate for DNA testing and the occurrence of germline mosaicism in about 2% of individuals with tuberous sclerosis complex make it difficult to exclude the diagnosis of tuberous sclerosis complex in family members. ( J Child Neurol 2004; 19:643-649).
Standardized Whole Brain Mapping of Tubers and Subependymal Nodules in Tuberous Sclerosis Complex
Authors: Ridler Khanum , Suckling John , Higgins Nicholas , Bolton Patrick , Bullmore Edward
Published: July 2017

Tuberous sclerosis complex is associated with radiologically visible abnormalities of brain structure, principally tubers and subependymal nodules. We reviewed the literature on neuroimaging of tubers and subependymal nodules and found qualitative evidence of bilateral, predominantly frontal distribution of tubers and bilateral, predominantly subcortical distribution of subependymal nodules in prior studies of pediatric samples. We studied 25 high-functioning adults with tuberous sclerosis complex and normal IQ, acquiring both dual spin-echo and fluid-attenuated inversion recovery magnetic resonance imaging sequences to optimize radiologic diagnosis of tubers and nodules. Individual lesion maps were then coregistered in a standard stereotactic space to facilitate construction of lesion density maps and estimation of lesion density in cortical and subcortical regions reliably defined by a parcellated template image. We found the highest frequency of tubers in frontal lobes and the highest density of tubers in parietal regions. There was significant regional variation in tuber density but no significant lateralization of frequently bilateral tubers. Nodules were located predominantly in the caudate nucleus and were not significantly lateralized. Tuber and nodule volumes were significantly positively correlated. Tuber volume was larger, on average, in patients with a lifetime history of epilepsy, but there was no correlation between IQ and these measures of lesion load. Contemporary image processing tools can be used to enhance quantitative, whole brain analysis of lesion load in patients with tuberous sclerosis complex. ( J Child Neurol 2004; 19:658-665).
Non-Neurologic Manifestations of Tuberous Sclerosis Complex
Authors: Neal Franz David
Published: July 2017

Tuberous sclerosis complex is a heterogeneous genetic disorder affecting multiple organ systems at various points throughout the lifespan. Increasingly, neurologically asymptomatic adults are being diagnosed with tuberous sclerosis complex through renal or pulmonary presentations. Although chiefly recognized for its cerebral manifestations, understanding of the non-neurologic aspects of the disorder has advanced greatly in recent years, and they are reviewed here. ( J Child Neurol 2004;19:690—698).
Mouse Models of Tuberous Sclerosis Complex
Authors: Scheidenhelm Danielle K. , Gutmann David H.
Published: July 2017

The most devastating complications of tuberous sclerosis complex affect the central nervous system and include epilepsy, mental retardation, autism, and glial tumors. Mutations in one of two genes, TSC1 and TSC2, result in a similar disease phenotype by disrupting the normal interaction of their protein products, hamartin and tuberin, which form a functional signaling complex. Disruption of these genes in the brain results in abnormal cellular differentiation, migration, and proliferation, giving rise to characteristic brain lesions called cortical tubers. Relevant animal models, including conventional and conditional knockout mice, are valuable tools for studying the normal functions of tuberin and hamartin and how disruption of their expression gives rise to the variety of clinical features that characterize tuberous sclerosis complex. In the future, these animals will be invaluable preclinical models for the development of highly specific and efficacious treatments for children affected with tuberous sclerosis complex. ( J Child Neurol 2004;19:726—733).
Comparative Audit of Clinical Research in Pediatric Neurology
Authors: Al-Futaisi Amna , Shevell Michael
Published: July 2017

Clinical research involves direct observation or data collection on human subjects. This study was conducted to evaluate the profile of pediatric neurology clinical research over a decade. Trends in pediatric neurology clinical research were documented through a systematic comparative review of articles published in selected journals. Eleven journals (five pediatric neurology, three general neurology, three general pediatrics) were systematically reviewed for articles involving a majority of human subjects less than 18 years of age for the years 1990 and 2000. Three hundred thirty-five clinical research articles in pediatric neurology were identified in the 11 journals for 1990 and 398 for 2000, a 19% increase. A statistically significant increase in analytic design (21.8% vs 39.5%; P = .01), statistical support (6% vs 16.6%; P < .0001), and multidisciplinary team (69.9% vs 87%; P = .003) was observed. In terms of specific study design, a significant decline in case reports (34.3% vs 10.3%; P < .0001) and an increase in case-control studies (11.3% vs 22.9%; P = .02) were evident over the 10-year interval. This comparative audit revealed that there has been a discernible change in the methodology profile of clinical research in child neurology over a decade. Trends apparently suggest a more rigorous approach to study design and investigation in this field. ( J Child Neurol 2004;19:882—886).
99mTc-HMPAO Single Photon Emission Computed Tomography (SPECT) in Both Asphyxiated and Epileptic Children With or Without Status Epilepticus
Authors: Öner Naci , Fikret Cermik T. , Alpay Mucalp , Turan Çağiτ , Alada Nükhet , Karasalihoğlu Serap
Published: July 2017

In this study, technetium 99m hexamethylpropyleneamine oxime (99mTc-HMPAO) single photon emission computed tomography (SPECT) was performed on 18 asphyxiated and epileptic children who also had a status epilepticus episode, and the results were compared with those for 21 children without a status epilepticus episode. All patients underwent a detailed neurologic history, interictal electroencephalography, computed tomography, and/or magnetic resonance imaging. Visual evaluation of the SPECT study showed that 16 patients of group 1 had 56 hypoperfused regions in cerebral blood flow. However, in group 2, visual evaluation showed only six detectable hypoperfusion areas in five patients. When an asymmetric index value of 3 was considered as a cutoff point, 82 regions in group 1 and 57 regions in group 2 were above this value after the quantitative SPECT evaluation. The mean number of pathologic brain regions was found to be higher in group 1 (5.1 ± 4.3) than in group 2 (2.7 ± 2.4) ( P = .014). The localization of hypoperfused regions that were observed in temporal and frontal regions was generally similar in both groups. In conclusion, the functional activities of the brain vary in both asphyctic and epileptic children, with and without status epilepticus. These children might be candidates for refractory convulsive disease, and interictal SPECT can be a reliable method for the detection of brain lesions in these patients. ( J Child Neurol 2005;20:560—565).
Sturge-Weber Syndrome: Altered Blood Vessel Fibronectin Expression and Morphology
Authors: Comi Anne M. , Weisz Catherine J. C. , Highet Bridget H. , Skolasky Richard L. , Pardo Carlos A. , Hess Ellen J.
Published: July 2017

Sturge-Weber syndrome presents with vascular malformations of the brain, skin, and eye. Fibronectin has potent effects on angiogenesis, vessel remodeling, and vessel innervation density. To determine fibronectin expression in the blood vessels of Sturge-Weber syndrome brain and skin tissue and to quantify the density and circumference of Sturge-Weber syndrome blood vessels by type compared with controls, we performed in situ hybridization for fibronectin messenger ribonucleic acid (RNA) expression on six Sturge-Weber syndrome cortical brain samples, six epilepsy brain samples, skin from two port-wine stain skin lesions, and two normal skin samples from two subjects with Sturge-Weber syndrome. Fibronectin messenger RNA was expressed in blood vessels and endothelial cells in the parenchyma of both Sturge-Weber syndrome and control brain tissues and in skin samples. Fibronectin expression was significantly reduced by 23% in the Sturge-Weber syndrome meningeal vessels compared with the epilepsy controls ( P < .01). Fibronectin expression was significantly increased by 19% in the Sturge-Weber syndrome parenchymal vessels compared with the epilepsy controls ( P < .05). No difference was found in the expression of fibronectin in port-wine stain skin blood vessels. The density of leptomeningeal blood vessels in the Sturge-Weber syndrome brain tissue samples was 45% greater than in the epilepsy samples ( P < .05). Blood vessel circumference was significantly decreased in the Sturge-Weber syndrome meningeal vessels compared with the controls (27%; P < .05). When blood vessels from different brain regions were compared, fibronectin expression was decreased in Sturge-Weber syndrome meningeal vessels and was increased in the parenchymal vessels. Altered blood vessel fibronectin expression in Sturge-Weber syndrome could contribute to abnormal vascular structure and function in this disorder. ( J Child Neurol 2005;20:572—577).
Heart, Brain, and Mind
Authors: Perkins Freedom F. , Butler Ian J.
Published: July 2017

Ischemic strokes in children, although generally rare events, are more prevalent than commonly believed and can adversely affect brain development. Ischemic strokes in children have been associated with various risk factors, including coagulation defects, cardiac anomalies, inborn errors of metabolism, infections, trauma, and even migraine headaches. We present four children with two or more of these risk factors, indicating multifactorial causes of strokes in children. Neuropsychologic testing in two of our cases also underscores cognitive decline as a result of recurrent strokes. ( J Child Neurol 2005;20:578—582).
Efficacy of Levetiracetam at 12 Months in Children Classified by Seizure Type, Cognitive Status, and Previous Anticonvulsant Drug Use
Authors: Mandelbaum David E. , Bunch Marjorie , Kugler Steven L. , Venkatasubramanian Anuradha , Wollack Jan B.
Published: July 2017

In a retrospective study of 59 children (ages 9 months to 23 years; mean age 11 years) with intractable epilepsy, seizure frequency was determined before and after 12 months of levetiracetam therapy. Charts were reviewed for seizure type (focal, generalized, or mixed), cognitive function (no special education versus special education), concomitant anticonvulsant medications (range 0—5), and the number of previous anticonvulsant drugs (range 1—12). Good to excellent seizure control (50—100% reduction) was attained in 6 (40%) patients with focal seizures, 16 (55%) patients with generalized seizures, and 8 (61%) patients with mixed seizures; these efficacy rates were not significantly different. The efficacy of levetiracetam was independent of cognitive status. Adverse effects were not associated with higher mean doses. This could be attributable to different rates of metabolism or represent idiosyncratic responses to the medication. Our finding that those children taking the combination of levetiracetam and zonisamide had a significantly worse outcome than those on levetiracetam and a different drug warrants further study, both clinically and from the standpoint of the mechanisms of action of levetiracetam and zonisamide and/or their pharmacodynamic interactions. ( J Child Neurol 2005;20:590—594).
Streptococcus oralis as a Risk Factor for Middle Cerebral Artery Thrombosis
Authors: Kazanci Ebru , Oguz Kader Karli , Gurgey Aytemiz , Topçu Meral
Published: July 2017

We reported a case of an 8-year-old boy who was presented to the emergency department with left-sided hemiparesis. Computed tomography showed hypodense areas in the territory of the right middle cerebral artery, indicating acute cerebral infarct. Diagnostic evaluation was performed to identify the etiology. On the eighteenth day of hospitalization, cerebrospinal fluid cultures yielded Streptococcus oralis . We hypothesized that the source of the oral pathogen was an abscess belonging to his upper left fourth tooth, which, by a transient bacteremia, had invaded the central nervous system, and skipping the meninges caused local inflammatory arteritis of the carotid artery, leading to cerebral infarction. Sulbactam-ampicillin therapy was initiated for 14 days, and he was discharged with anticoagulation therapy. ( J Child Neurol 2005;20:611—613. )
Type 1 Ataxia With Oculomotor Apraxia With Aprataxin Gene Mutations in Two American Children
Authors: Tsao Chang Y. , Paulson George
Published: July 2017

Ataxia and oculomotor apraxia are seen in ataxia-telangiectasia, type 1 ataxia with oculomotor apraxia, and type 2 ataxia with oculomotor apraxia; however, only type 1 ataxia with oculomotor apraxia is associated with aprataxin gene mutation. We report two American children, a sister and a brother, with type 1 ataxia with oculomotor apraxia and aprataxin gene mutations and briefly review type 1 ataxia with oculomotor apraxia. ( J Child Neurol 2005;20:6190—620).
Experimental investigation on a three-fluid absorption refrigeration machine
Authors: Vicatos G
Published: July 2017

This paper investigates the performance of a domestic-size three-fluid absorption refrigeration system. The boiler, lift tube, vapour-liquid separator and the heat exchanger were modified, while maintaining the same principle of operation. The unit was charged with a recommended concentration of 34 per cent aqueous ammonia solution containing the right amounts of sodium dichromate and caustic soda. Hydrogen was charged, the pressure of which was increased from the lowest of 7.5 bar to the highest of 27.5 bar in steps of 2.5 bar. For each of these hydrogen pressures, data were recorded using different power supplies of 260, 315 and 370 W. The data recorded were in the form of total pressure in the system and temperatures taken from strategic points on the unit.

The data collected from the experiment are shown in the form of temperature response graphs to facilitate easy comparison within the various working conditions. Although there are no performance characteristics available from the manufacturer, it is believed that the modified components have improved the time response of the unit.
Reliability and safety strategies in living organisms: Potential for biomimicking
Authors: Burgess S C
Published: July 2017

The natural world contains millions of species of living organisms and these contain a great range of components and processes that have been proven to function very reliably in harsh environments. One of the key reasons for the high reliability of living organisms is the existence of reliability and safety strategies. This paper presents a review of 32 reliability and safety strategies that are found in living organisms and discusses to what extent each of these strategies is used, or can be used, in engineering systems, particularly process systems. There are several strategies used in nature that are not used much in engineering systems. As engineering systems take on more of the characteristics of biological systems, there are potential benefits in copying the strategies of nature.
Opportunities for innovation with screw compressors
Authors: Stosic N , Smith I K , Kovacevic A
Published: July 2017

It is falsely considered, but widely accepted, that little can now be done to improve the screw compressor process and design. Screw compressors are indeed a mature product today and they form a highly competitive market, especially the oil-flooded air compressor. However, the simultaneous efforts of a large number of manufacturers have resulted in a compact and efficient oil-flooded screw compressor machine. Even small design details now tell the achievement of better compressor efficiency, and there is still some place left for implementation of new methods and procedures that will undoubtedly result in a better final product. New rotor generation procedures, rotor and compressor design optimization for a specified compressor duty and specialized compressor design are innovation elements that are continually improving and developing screw compressors and opening up hitherto unknown ways to produce compressors with better features. Also, the development of a combined compression and expansion machine is reported which could further increase the useful range of application of such machines, especially in refrigeration systems. A review of recent results of computational fluid dynamics (CFD) in screw machines is also given in the paper.
Polyfunctional plants for industrial waste disposal: A case study for small enterprises
Authors: Caputo A C , Pelagagge P M
Published: July 2017

Waste production represents a very critical problem for small enterprises which have to take charge of disposal activities and their related costs but cannot afford autonomous solutions owing to technical and financial constraints. For this kind of enterprise, polyfunctional plants appear to be one of the most promising solutions that show ability in the treatment and disposal of a wide range of wastes, performing collection and storage tasks too. At the same time, such plants allow stricter environmental control, an increased reuse of both waste materials and energy and, finally, lower capital and operating costs. In this paper a case study referring to small and very small enterprises in the Rome industrial area is presented. After characterization of the reference scenario, leading to an annual amount of about 165000 tons of waste to be treated, the technoeconomic feasibility study of the plant has been carried out. Overall economic evaluation indexes and risk analysis of the investment are also presented.
America's Policy towards Iraq
Authors: Fabian K.P.
Published: July 2017

“I had been instructed to implement a policy that satisfies the definition of genocide, a deliberate policy that has effectively killed well over a million individuals, children and adults.” (Dennis Halliday, UN Humanitarian Coordinator in Iraq, 1997–98).

“More than one million Iraqis have died −500,000 of them children as a direct consequence of economic sanctions. As many as 12% of the children surveyed in Baghdad are wasted, 28% stunted, and 29% underweight”. (Morbidity and Mortality among Iraqi Children, 1990–98, FAO, December 1999).
India's Energy Diplomacy in Francophone Africa: Competitive-Cooperation with China∗
Authors: Pathak Vidhan
Published: July 2017

Energy security issues have brought Francophone Africa recently into India's strategic map. In fact, India has recently taken initiatives and turn towards Francophone Africa for diversifying its energy sources. While US, Europe and China have already jumped into the oil exploration process in this region, India has to make a dent on the basis of its historical linkages with these countries. India is working out an elaborate energy procurement plan through its energy diplomacy in this region. The increasing interest of US and European powers and their strategies for African oil has enabled India to formulate policy framework for energy cooperation with China in Francophone Africa. However, the need for energy security has also the possibility of competition and confrontation between India and China. Indian energy diplomacy in Francophone Africa cannot ignore the competition with China and its ramifications. The Chinese factor is quite evident in India's energy diplomacy in this region. As India enters Francophone Africa in search of oil equity, it is increasingly facing a Chinese challenge. Bilateral competition to secure oilfields led to some rivalry between both wherein the national oil companies from both countries were playing the game of one up-manship. In the battle for the control of equity oil in Africa, the Chinese have already outbid OVL twice, in Sudan and Angola. China has been hunting for oil equity for a longer period than India. And this underlines the importance of energy cooperation between both countries in the Francophone Africa. Both, India and China have managed to turn their much-vaunted rivalry for the acquisition of oil and gas assets in third countries into a partnership that could well alter the basic dynamics of the global energy market. This paper has underlined the evolving Indian energy diplomacy in Francophone Africa, “competitive-cooperation” with China in the region by situating China and India in the demand and Francophone Africa in the supply side of the diversified world energy regime.
High Technology Terrorism: A Threat to Global Security
Authors: Kaur Kuljit
Published: July 2017

It is to be understood that terrorist violence is neither spontaneous nor random. Terrorists are always aware of the implications of their acts. Evidence supports the contention that terrorists are not able to avail themselves of the present technologies. To manufacture their own nuclear weapons, terrorists would require both strategic, special nuclear materials and the expertise to convert them into a bomb or radiological weapon. Whether terrorists of the future will be able to achieve a nuclear weapons capability depends upon several factors. The paper attempts to deal with those factors in detail.
India-China Relations: A Positive Frame
Authors: Mohanty Manoranjan
Published: July 2017

Pronouncements both by the Indian and Chinese governments after the inauguration of the Rajiv Gandhi administration reflect more than diplomatic niceties. They manifest a positive frame which has emerged in the recent years for a steady development of India-China relations. The pace at which the economic, scientific and cultural exchange programmes have expanded provides some ground for optimism for the sixth round of talks on the border scheduled for later this year in New Delhi. Though there is no indication of an emerging settlement on the border, still the stage is getting set for a serious progress on this issue.

Addressing the Congress Parliamentary Party on the eve of the first session of the new Lok Sabha, Prime Minister Rajiv Gandhi expressed his satisfaction over the progress made in the talks with China, but he also cautioned that the way towards a full agreement was very long. The President's address to Parliament on 17 January 1985 also indicated the same situation.' He said, “Our relations with China have shown improvement. We shall persevere in seeking a solution to the boundary question.” The Chinese have warmly reciprocated these feelings. Attending the Republic Day reception given by the Indian Ambassador A.P. Venkateswaran in Beijing, the Chinese Foreign Minister Wu Xueqian said that he saw no real conflict of fundamental interests between India and China and there were bright prospects for bilateral cooperation in the future.

There are several factors contributing to the emerging positive frame for Sino-Indian relations. The strategic shift in China's South Asia policy, the overall orientation of China's “independent foreign policy,” and increasing exchange between India and China, are important among them. The new factors facilitating this trend are the assertion of technological management approaches to the problems of development of the two countries by the current leaders and the extrems care with which China covers Indian developments in its press; this is evident from the Chinese reports on the Punjab issue.
India's Africa Policy
Authors: Chhabra Hari Sharan
Published: July 2017

Soon after assuming office Prime Minister Rajiv Gandhi announced a donation of 100,000 tons of wheat to the famine-stricken countries of Africa. The government also announced that it would be sending a team of doctors and medical supplies to some needy countries on the African continent. That the new government responded to the urgent needs of Africa shows what great regard it has for the suffering masses of the neighbouring continent. This gesture has been greatly appreciated in Africa, even if the Indian help is rather modest.

In view of the old, historic and friendly relations with peoples of Africa, it is now India's desire to strengthen these relations with the present 50-odd newly independent countries of the African continent. These countries no doubt present an untapped opportunity for trade and technical collaboration, but for the success of our foreign policy the numerical strength of Africa— nearly one-third the United Nations- is immensely important. It is, indeed, a worthwhile gathering of friends to have in international forums.

India's Africa policy has two facets: its role as an uncompromising fighter against colonialism and racialism and its strong faith in South-South cooperation.