bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Learning Behavior Based on ARCS Learning Motivation Model
Authors: Wang Yi , Jiang Yong Ling
Published: April 2021

Based on the ARCS Motivation Model proposed by John M. Keller, the instructional design of blended learning is carried out, and the "Python Programming" course is taken as an example for empirical research. Pearson correlation analysis and Apriori algorithm are used to analyse the data of students' learning behavior. The results show that the pre-class preview learning behaviour has a significant impact on students' learning process. Through the association analysis of learning process, it is found that the difference between pre-class preview and self-test learning behavior has a significant impact on the learning outcomes. The empirical conclusion of this paper has important reference value for optimizing blended learning methods and data mining analysis based on learning behavior, so as to support teachers to carry out personalized guidance and feedback for students.
Green Synthesis of Silver Nanoparticles Using Aqueous Extract of Lamium album and their Antifungal Properties
Authors: Zareshahrabadi Zahra , Karami Fatemeh , Taghizadeh Saeed , Iraji Aida , Amani Ali Mohammad , Motamedi Marjan , Zomorodian Kamiar
Published: April 2021

Biosynthesis of novel metal nanoparticles (especially silver) using plant derivatives has received increasing attention due to their eco-friendly and potential applications in pharmaceutical and medical fields. In this study, silver nanoparticles were synthesized by using aqueous extract of Lamium album as a biocompatible and green method. The synthesized silver nanoparticles were characterized by Ultraviolet-visible (UV–vis) Spectroscopy, Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Dynamic Light Scattering (DLS) Analysis. Inhibitory activity of silver nanoparticles on fungal growth was evaluated and inhibition of Candida albicans biofilms formation was measured using XTT assay. Their antioxidant and cytotoxic properties have also been evaluated.The synthesized AgNPs were mostly spherical in shape with an average size of nearly 25.2 nm. The AgNPs were crystalline in nature and have a face-centered cubic structure. The results of zeta potential value for AgNPs were −30 mV indicating the normal stability of the synthesized nanoparticles in colloidal systems. The result of antifungal activities showed that the biosynthesized silver nanoparticles had inhibitory activity against Candida albicans, C. tropicalis, C. krusei, C. glabrata, C. dubliniensis, C. parapsilosis, Cryptococcus neoformance, Aspergillus flavus, A. clavatus, Aspergillus fumigatus, Pseudallescheria boydii and Exophiala dermatitidis. The nanoparticles inhibited the Candida albicans biofilm formation in a dose-dependent manner. The cytotoxicity study of silver nanoparticles was revealed IC50 of 110.75 μg/mL against liver cell lines. The recognized bioactivity confirmed by the synthesized silver nanoparticles directs towards the potential for using as an antioxidant, antifungal, and cytotoxic agent.Keywords: Green synthesis, Antifungal activities, Silver nanoparticles, Lamium album, Biofilm formation.
The Effect of Synthesis Parameters on the Size, Composition, and Stability of Iron Nanoparticles
Authors: King Julie E. , Evans Adam W. , Hah Hien Yoong , Johnson Charles E. , Rondinone Adam J. , Pawel Michelle D. , Ho Hoi C. , Johnson Jacqueline A.
Published: April 2021

Magnetic nanoparticles (MNPs) have many uses for biomedical applications including drug delivery, magnetic resonance imaging (MRI) contrast agents, theranostics and hyperthermia. MNPs photo-thermally heated by laser light could be used to treat the typically difficult to access tumors such as glioblastomas. Due to their high magnetic saturation, monometallic iron nanoparticles would have an edge over iron oxide nanoparticles currently being investigated for hyperthermia. The goal of this study was to synthesize spherical iron nanoparticles less than 10 nm in diameter by thermal decomposition. The ability of various biocompatible coatings to protect the metallic iron nanoparticles from oxidation was investigated. Coatings studied included Brij, polyethylene glycol and iron oxide. Transmission electron microscopy and Mössbauer spectroscopy were utilized to characterize the coated and uncoated iron nanoparticles’ size and oxidation state to evaluate the effectiveness of the coatings and the procedures in which the coatings were applied. A ferrite shell was found to provide the best stabilization; however, its longer synthesis time increased particle size distribution. Polymer coatings provided biocompatibility but did not prevent oxidation.
Simple Fabrication of PEG Modified W18O49 for Enhanced Adsorption Performance towards Methylene Blue
Authors: Fu Hai Yang , Li Li Xuejiao , Sun Sun Wei , Liu Liu Dongyue , Gao Gao Xiaofei , Dong Li Min , Fu Haiyang
Published: April 2021

The W18O49 nanoparticles were synthesized by solvothermal method with tungsten chloride as raw material and n-propanol as solvent. Polyethylene glycol 400 (PEG-400) was modified for W18O49 nanoparticles (W18O49@PEG). The structure and morphology of W18O49 and W18O49@PEG were characterized by XRD and SEM. Methylene blue aqueous solution was used as wastewater adsorption model. And the comparative experiments with other absorbent materials, such as artificial zeolite and activated carbon were also conducted. The results revealed that after modifying by PEG-400, W18O49 has a better adsorption performance than other materials due to its large specific surface area and high surface energy. Finally adsorption circulation experiment was performed，the results indicate that the W18O49@PEG nanoparticles show great potential in the treatment of colored wastewater.
Approach for the Automated Analysis of Geometrical Clinch Joint Characteristics
Authors: Zirngibl Christoph , Schleich Benjamin
Published: April 2021

Due to their cost-efficiency and environmental friendliness, the demand of mechanical joining processes is constantly rising. However, the dimensioning and design of joints and suitable processes are mainly based on expert knowledge and few experimental data. Therefore, the performance of numerical and experimental studies enables the generation of optimized joining geometries. However, the manual evaluation of the results of such studies is often highly time-consuming. As a novel solution, image segmentation and machine learning algorithm provide methods to automate the analysis process. Motivated by this, the paper presents an approach for the automated analysis of geometrical characteristics using clinching as an example.
Stretch Forming of Ti-6Al-4V Hybrid Parts at Elevated Temperatures
Authors: Hafenecker Jan , Rothfelder Richard , Schmidt Michael , Merklein Marion
Published: April 2021

Hybrid components produced by two or more different process technologies grant the possibility to compensate the drawbacks of the used processes. The combination of additive manufacturing (AM) and forming offers geometrical freedom in extensions of geometrical simple parts in a cost-efficient way. Unlike the combination of bulk metal forming and AM, sheet metal forming and AM is less investigated. Especially for Ti-6Al-4V, which is widely used in AM but has a low formability at room temperature, research is still needed. In this study, the formability of hybrid parts made of Ti‑6Al‑V consisting of sheet material and additively manufactured elements (AME) is investigated for a hemispherical punch geometry. Thus, a designed tool for forming of hybrid parts at elevated temperatures is used. First investigations with a specially designed stretch forming tool demonstrate the distinct influence of the additively manufactured bodies on the stretch forming process of hybrid parts made of Ti‑6Al‑4V. Namely, the achievable drawing depth is reduced for hybrid parts as the functional elements are placed in the area of highest stresses, distorting material flow.
Effect of Stretching on Springback in Rotary Stretch Bending of Aluminium Alloy Profiles
Authors: Ma Jun , Welo Togeir , Blindheim Jørgen , Ha Taekwang
Published: April 2021

Stretch bending is widely used for manufacturing profile-type parts. However, one of the challenges faced by the bending-type forming processes is springback, which significantly reduces the dimensional accuracy of formed part, process flexibility and overall equipment effectiveness. In this study, we focus on the springback behavior in a newly developed flexible rotary stretch bending process for profiles. Using the Al-Mg-Si alloy rectangular hollow extrusions, the effect of stretching on springback, as well as process capability, is evaluated by a series of carefully designed experiments conducted for a wide range of stretching strains. Increasing the stretching strain from about 2% to 4%, the springback chord height can be reduced by about 32% and the process capability can be improved significantly, showing the strong ability of the novel flexible stretch bending strategy for controlling springback and dimensional accuracy.
Investigation of the Influence of a Superimposed Oscillated Forming Process on Forming Characteristics
Authors: Müller Philipp , Hübner Sven , Rosenbusch Daniel , Vogt Hendrik , Behrens Bernd-Arno
Published: April 2021

The increasing demand for resource-efficient production methods is driving the development of new technologies. Sheet bulk metal forming (SBMF) offers the possibility to combine sheet metal and bulk forming operations. This allows the production of complex functional components with secondary forming elements from sheet metal. Compared to other production techniques such as machining, a more efficient use of material can be achieved. Further advantages are a near net shape production and increased strain hardening. SBMF processes are limited by forming technology boundaries. These include high forming forces, incomplete mould fillings and limited surface qualities. In this research, the possibility of enhancing the material flow, improving surface quality and reducing the tool loads in SBMF-processes is investigated by using a superimposed oscillation. The focus here is on achieving a high surface quality of components produced by forming technology and an enhanced material flow during forming. For this purpose, a forming process for ironing an axial gear geometry is superimposed with an oscillation in the main force flow.
Influence of Roughness and Curing Temperature on the Strength of Aluminum Adhesively Bonded Joints
Authors: Rotella Giovanna , Saffioti Maria Rosaria , Sanguedolce Michela , Filice Luigino
Published: April 2021

This work presents a comprehensive experimental study on the effect of surface roughness and adhesive curing temperature on adhesively bonded joints of AA6082. The modification of surface morphology has been assessed by roughness measurements (contact and non-contact profilometry). In addition, mechanical changes in the resin properties due to different curing time have been probed through a series of instrumented indentation tests. Thus, adhesive bonded single lap joints were fabricated and tested to assess the changes in shear strength at varying surface roughness and curing conditions. The obtained results indicate the ability of the roughened surface to improve the joint strength together with the adequate combination of curing temperature and time among those suggested by the manufacturer.
Microstructure and Formability of Laser Welded Dissimilar Butt Joints of Austenitic-Ferritic Stainless Steels
Authors: Keskitalo Markku , Hamada Atef S. , Hietala Mikko , Jaskari Matias , Järvenpää Antti
Published: April 2021

Dissimilar laser welding of ferritic, type EN 1.4509, and austenitic, type EN 1.4307, stainless steel sheets was conducted at different energy inputs 30 and 80 J/mm and under different shield gases Ar and N and without shielding gas to evaluate the microstructure and hardness of the welded zone. The formability tests, using Erichsen principle, were carried out to determine the deformation behaviour of the dissimilar welded joints under biaxial straining. The fusion zone microstructure analysis revealed that the predominant phase structure is columnar coarse ferritic grains with slightly small content of austenite in the ferrite grain boundaries. The formability of the welded joints under Ar and N shielding gases is significantly improved, i.e., higher plasticity, compared with welded joints without shielding gas at both energy inputs.
Material Model for the Production of Steel Fibers by Notch Rolling and Fulling
Authors: Biallas Alina , Merklein Marion
Published: April 2021

Concrete, which is reinforced by steel fibers, represents a multifunctional building material that is able to realize flexible but stable structures. As an alternative to the energy-intensive conventional production procedure wire drawing, a combination of a notch rolling and cyclic bending process is proposed by Stahl [1] to produce those fibers. Besides representing the properties of steel fibers and the overall process, the paper brings the layout of both process steps into focus. Since notch rolling for the production of wire strip is mainly unexplored, a general conceptual design of the process and the rolling tools is performed, supplemented by a similar study on the fulling process. To enable a further evaluation of the process chain and its relevant process parameters, a numerical and experimental test phase using strip of a dual phase steel DP600 with a sheet thickness of t0 = 0.8 mm is intended in future. For ensuring high-quality numerical model, relevant behavior of the test strip is characterized through appropriate experiments and according material models in the present paper.
The Frictional Force between Slug and Die in Shear Cutting after Material Separation
Authors: Stahl Jens , Pätzold Isabella , van den Bosch Lucas , Kindsmüller Alexander , Golle Roland , Volk Wolfram
Published: April 2021

Frictional forces in sheet metal blanking are central in different aspects, e.g. in wear prediction, validation of simulation models or in so called slug pulling. The latter is a phenomenon where the slug is pulled out of the die by the punch after the sheet metal is separated. This leads to process disturbances reaching from a blocked belt feeder up to severe tool damage caused by the simultaneous cutting of the slug and the sheet metal strip. A sufficiently high frictional force between the slug and the die prevents this effect. Despite its importance, this force and its causes have not yet been investigated in detail. A method was developed in this paper to measure the frictional force between slug and die. A shear cutting tool with an integrated piezoelectric load cell and an inductive position sensor was used on a stamping press to cut sheet metal made of CuSn6 (R350, thickness 1 mm). The die clearance, the punch edge radii and the lubrication conditions were varied. A larger die clearance resulted in a lower frictional force while a larger punch edge radius increased it significantly. Lubrication reduced the frictional force, especially for small die clearances. Finally, the cause of the frictional force was investigated by identifying the relevant springback modes of the slugs. This was carried out by correlating the slugs' deflection, oversize, and clean cut height with the frictional force. Especially the slug oversize, i.e. the difference between the slug's diameter and the die's inner diameter, revealed a strong correlation. Calculations showed that the deformation in radial direction is the main cause of the frictional force between slug and die. It suggests that the slug oversize is a good measure for the magnitude of the frictional force.
New Approach for Versatile Self Piercing Riveting: Joining System and Auxiliary Part
Authors: Kappe Fabian , Bobbert Mathias , Meschut Gerson
Published: April 2021

The increasing use of multi-material constructions lead to a continuous increase in the use of mechanical joining techniques due to the wide range of joining possibilities as well as the high load-bearing capacities of the joints. Nevertheless, the currently rigid tool systems are not able to react to changing boundary conditions, like changing the material-geometry-combination. Therefore research work is crucial with regard to versatile joining systems. In this paper, a new approach for a versatile self-piercing riveting process considering the joining system as well as the auxiliary joining part is presented.
Determination of the Biaxial Anisotropy Coefficient Using a Single Layer Sheet Metal Compression Test
Authors: Hetz Peter , Lenzen Matthias , Kraus Martin , Merklein Marion
Published: April 2021

Numerical process design leads to cost and time savings in sheet metal forming processes. Therefore, a modeling of the material behavior is required to map the flow properties of sheet metal. For the identification of current yield criteria, the yield strength and the hardening behavior as well as the Lankford coefficients are taken into account. By considering the anisotropy as a function of rolling direction and stress state, the prediction quality of anisotropic materials is improved by a more accurate modeling of the yield locus curve. According to the current state of the art, the layer compression test is used to determine the corresponding Lankford coefficient for the biaxial tensile stress state. However, the test setup and the test procedure is quite challenging compared to other tests for the material characterization. Due to this, the test is only of limited suitability if only the Lankford coefficient has to be determined. In this contribution, a simplified test is presented. It is a reduction of the layer compression test to one single sheet layer. So the Lankford coefficient for the biaxial tensile stress state can be analyzed with a significantly lower test effort. The results prove the applicability of the proposed test for an easy and time efficient characterization of the biaxial Lankford coefficient.
Determination of the Interface Structural Resolution of an Industrial X-Ray Computed Tomograph Using a Spherical Specimen and a Gap Specimen Consisting of Gauge Blocks
Authors: Busch Matthias , Hausotte Tino
Published: April 2021

Industrial X-ray computed tomography (XCT) is a tool for non-destructive testing and a volumetric analysis method with the ability to measure dimensions and geometry inside a component without destroying it. However, XCT is a relatively young technology in the field of dimensional metrology and thus faces several challenges. The achievement of a high measurement resolution, which is re-quired to detect small geometrical features, depends on a variety of influencing factors. In this arti-cle, the interface structural resolution (ISR) as one of the key challenges will be investigated. The two-sphere standard called the hourglass standard allows the determination of the structural resolu-tion by evaluation of the surrounding area of an ideal point contact of two spheres after the CT re-construction in form of a neck-shaped transition. Close to the contact point of the two spheres two opposing surfaces exist. Their distances from each other increase as the distance from the contact point of the two spheres increase. The determination of the distances between the spheres’ surface allows a statement about the ISR. A new developed specimen or standard with a variable gap size consisting of calibrated parallel gauge blocks allows statements about the ISR, too. Because of the higher number of probing points of the gauge block standard the results of the determined ISR are more stable compared to the hourglass standard. This paper compares the results of the computed tomography measurements for the designed interface structural resolution standard with those of the hourglass standard.
Development of a Method for the Identification of Friction Coefficients in Sheet Metal Materials for the Numerical Simulation of Clinching Processes
Authors: Rossel Moritz , Böhnke Max , Bielak Christian Roman , Bobbert Mathias , Meschut Gerson
Published: April 2021

In order to reduce the fuel consumption and consequently the greenhouse emissions, the automotive industry is implementing lightweight constructions in the body in white production. As a result, the use of aluminum alloys is continuously increasing. Due to poor weldability of aluminum in combination with other materials, mechanical joining technologies like clinching are increasingly used. In order to predict relevant characteristics of clinched joints and to ensure the reliability of the process, it is simulated numerically during product development processes. In this regard the predictive accuracy of the simulated process highly depends on the implemented friction model. In particular, the frictional behavior between the sheet metals affects the geometrical formation of the clinched joint significantly. This paper presents a testing method, which enables to determine the frictional coefficients between sheet metal materials for the simulation of clinching processes. For this purpose, the correlation of interface pressure and the relative velocity between aluminum sheets in clinching processes is investigated using numerical simulation. Furthermore, the developed testing method focuses on the specimen geometry as well as the reproduction of the occurring friction conditions between two sheet metal materials in clinching processes. Based on a methodical approach the test setup is explained and the functionality of the method is proven by experimental tests using sheet metal material EN AW6014.
Indole-3-Carbinol–Dependent Aryl Hydrocarbon Receptor Signaling Attenuates the Inflammatory Response in Experimental Necrotizing Enterocolitis
Authors: Nolan Lila S , Mihi Belgacem , Agrawal Pranjal , Gong Qingqing , Rimer Jamie M , Bidani Shay S , Gale Sarah E , Goree Martin , Hu Elise , Lanik Wyatt E , Huang Elizabeth , Bando Jennifer K , Liu Victoria , Lewis Angela N , Bustos Aiza , Hodzic Zerina , Laury Marie L , Good Misty
Published: April 2021

Necrotizing enterocolitis (NEC) causes significant morbidity and mortality in premature infants; therefore, the identification of therapeutic and preventative strategies against NEC remains a high priority. The ligand-dependent transcription factor aryl hydrocarbon receptor (AhR) is well known to contribute to the regulation of intestinal microbial communities and amelioration of intestinal inflammation. However, the role of AhR signaling in NEC is unclear. Experimental NEC was induced in 4-d-old wild-type mice or mice lacking AhR expression in the intestinal epithelial cells or AhR expression in CD11c+ cells (AhRΔCD11c) by subjecting animals to twice daily hypoxic stress and gavage feeding with formula supplemented with LPS and enteric bacteria. During NEC, compared with wild-type mice treated with vehicle, littermates treated with an AhR proligand, indole-3-carbinol, had reduced expression of Il1b and Marco, a scavenger receptor that mediates dendritic cell activation and the recognition and clearance of bacterial pathogens by macrophages. Furthermore, indole-3-carbinol treatment led to the downregulation of genes involved in cytokine and chemokine, as revealed by pathway enrichment analysis. AhR expression in the intestinal epithelial cells and their cre-negative mouse littermates were similarly susceptible to experimental NEC, whereas AhRΔCD11c mice with NEC exhibited heightened inflammatory responses compared with their cre-negative mouse littermates. In seeking to determine the mechanisms involved in this increased inflammatory response, we identified the Tim-4− monocyte–dependent subset of macrophages as increased in AhRΔCD11c mice compared with their cre-negative littermates. Taken together, these findings demonstrate the potential for AhR ligands as a novel immunotherapeutic approach to the management of this devastating disease.
Assessment of the perceived stress and burden of family caregivers of the head-and-neck cancer patients at a tertiary care cancer center
Authors: Priya S. Sathiya , Shavi Girish R. , Sanga Ranganath , Shankar S. , Lalithambigai G. , Rahila C. , Santhakumari S.
Published: April 2021

Introduction:

Cancer is a major life-threatening disease and has an impact on both patients and their family members. Caring for cancer patients may lead to several levels of stress which may affect their own health as well as their quality of life.

Aim:

To assess the perceived stress and burden of family caregivers of head and neck cancer patients (HNC) attending cancer care centre at a tertiary care centre, Tamil Nadu.

Objectives:

To assess the perceived stress and the burden among caregivers of patients with head and neck cancer using the Perceived Stress Scale (PSS) and Caregiver Strain Index (CSI) respectively.

Materials and Method:

A Cross-sectional study was carried out for a period of three months among the caregivers of head and neck cancer patients at a cancer care centre, Madurai. A total of 200 caregivers were selected by Convenience sampling method. Data was collected using a pretested, self-structured, closed-ended questionnaire by face to face interview method.

Results:

The study population consisted of Caregivers aged 21-60 years, mostly females (80%), spouses (54%), employed (57%) and uneducated (66%). Most of the caregivers were from lower socioeconomic status (66%) and those who are providing care for 1 to 6 months were more in number. In this study, 82% of caregivers reported high caregiver burden (CSI ≥7) and 67% of caregivers reported high stress (PSS ≥ 26 - 40).

Conclusion:

Caregivers are experiencing significant burden, particularly with respect to their physical and psychological well-being, economic circumstances, social and personal relationships.
Rucabarib
Authors: Sachdeva Sandeep , Rabbani Tamkin Khan
Published: April 2021

Background:

Rucaparib is a drug with potential as maintenence monotherapy in ovarian cancers irrespective of genetic mutation.

Methods:

The results of the ARIEL 3 trial were analysed for the drug's prospects towards cure in ovarian and other pelvic malignancies.

Results:

Ovarian cancer patients with highly malignant tumors and relapses on platinum based chemotherapy exhibited statistically significant reductions in tumor size with maintenance Rucaparib therapy vis a vis placebo.

Conclusion:

Genetic heterogeneity of the tumor did not have an impact upon Rucaparib efficacy in ovarian carcinoma. More malignant and relapsed variants can effectively be treated with Rucaparib, thereby improving survival rates and quality of life.
Role of Roflumilast Combined with ESHAP Chemotherapy in Relapsed/Refractory Patients with Diffuse Large B-Cell Lymphoma
Authors: Kim Do Young , Nam Jehyun , Chung Joo-seop , Kim Sang-Woo , Shin Ho-Jin
Published: April 2021

Purpose There are unmet needs associated with the current treatment strategies for relapsed/refractory diffuse large B-cell lymphoma (DLBCL) due to the poor treatment outcomes of these strategies. Roflumilast, a selective phosphodiesterase-4 inhibitor used for treating chronic obstructive pulmonary disease, is effective against B-cell malignancy via phosphoinositide 3-kinase (PI3K)–activity suppression. We analyzed the effects of roflumilast combined with ESHAP (etoposide, cisplatin, methylprednisolone, and cytarabine) chemotherapy in experimental and clinical settings.Materials and Methods An in vitro study using lymphoma cell lines and a pilot study on relapsed/refractory DLBCL patients were conducted to investigate the effects and mechanism of the combination of roflumilast and chemotherapy. The complete response (CR), overall response rate (ORR), and 1-year progression-free survival (PFS) were analyzed.Results We found that roflumilast is efficient when combined with other chemotherapy drugs, especially cytarabine. Synergistic effects between these two drugs influence the translation of mammalian target of rapamycin and myeloid cell leukemia 1, resulting in apoptosis and inhibition of B-cell lymphoma proliferation. In clinical setting, the roflumilast group showed better rates of CR (46.2% vs. 34.6%), ORR (76.9% vs. 53.8%), and 1-year PFS (50.0% vs. 25.9%) compared with the control group, though not statistically significant. The roflumilast group showed a higher incidence of asthenia and gastrointestinal adverse events. However, grade 3 or 4 adverse events were similar in both groups.Conclusion We found that roflumilast, when combined with ESHAP chemotherapy, for relapsed/refractory DLBCL was clinically active and well tolerated. This combined treatment was able to suppress PI3K activity, which is correlated with the degree of clinical response.
THE PROBLEMATIQUE OF EDUCATION IN PAKISTAN
Authors:   International Islamic University, Islamabad.
Published: April 2021

Education in Pakistan hasn’t made any headway. Neither the planners nor the implementer have succeeded in realizing the aims and objectives set forth in the successive Educational Policies. This paper attempts to study the causes which have resulted in the resent stalemate. The author thinks that one of the reasons is the lack of emphasis on the acquisition of critical mass of modern education. The dichotomy of faith and reason in Pakistan’s educational policies has not allowed the emergence of that critical mass of intellectual vigour which could promote independent thinking among the students. The author is of the opinion that the concept of the “Ideology of Pakistan” has had its share in the intellectual stalemate obtaining today. On top of the above cited malaise the commercialization of education rampant in the world nowadays has also had its salutary effect on the Third World countries and Pakistan is no exception. What is urgently required by Pakistan is that due emphasis should be paid to the study of social sciences. The Think-Tank of Social Scientists, Anthropologists, Philosophers and Historians should start a reexamination of the paradigm and suggest alternatives without sacrificing the basic value system.
STRUCTURE AND PROPERTIES OF FeCr, CrAl AND FeCrAl COATINGS DEPOSITED BY CATHODIC ARC EVAPORATION
Authors: Vasilenko R.L. , Voyevodin V.N. , Belous V.А. , Bortnitskaya М.A. , Kolodiy І.V. , Klimenko І.О. , Ovcharenko V.D. , Kovalenko V.І. , Marinin V.G. , Ilchenko A.V. , Tikhonovsky М.А. , Kuprin A.S.
Published: April 2021

Protective coatings with different compositions of Fe, Cr, and Al were deposited by cathodic arc evaporation method on fragments of Zr1Nb alloy fuel claddings. The influence of the composition and structural state of the developed coatings on their physical and mechanical properties (microhardness, resistance to corrosion and cavitation and abrasive wear) has been studied. It is shown that the optimal combination of mechanical properties and high resistance to oxidation from a series of studied coatings FeCr, FeCrAl, and CrAl have coatings of the FeCrAl system with a concentration of Cr ~ 22 at.% and Al ~ 14.3 at.%. It was found that protective coatings such as FeCr, FeCrAl, and CrAl with a thickness of ~ 12 μm significantly increase the resistance to oxidation and prevent the destruction of fuel claddings under oxidation in air at a temperature of 1150 °C for 1 h.
CORROSION RESISTANCE OF REINFORCED LAYERS OF 15Х11МФ STEEL STEAM TURBINE BLADES
Authors: Hlushkova D.B. , Bahrov V.A. , Hrinchenko O.D. , Hnatiuk A.A. , Kalinina N.E. , Kalinin V.T.
Published: April 2021

The reliability of the vane apparatus of steam turbines largely determines the operation of the turbine as a whole. The results of scientific research indicate that the surface operation of the blades in the wet-steam flow is caused by a combination of corrosion and drip erosion. The presence of chemical elements and compounds in the working fluid intensifies the process of blade wear. The pH value of the working environment, which can fluctuate significantly during operation, has a significant effect on the wear characteristics. The influence of methods of strengthening the leading edges of steam turbine blades made of steel is analyzed 15H11MF on corrosion resistance. Corrosion tests of blade samples were carried out, the inlet edges of which were strengthened in three ways: high current amplification, electrospark alloying with T15K6 alloy, electrospark alloying with steel 15H11MF. According to the results of the tests, the layer strengthened by hardening by high-frequency currents has the lowest corrosion rate, the layer strengthened by electrospark alloying with T15K6 hard alloy has the highest. The corrosion rate of the layer reinforced by electrospark alloying of steel 15H11MF is 2.1 less than that of the layer reinforced with T15K6 alloy.
No Ritmo Do Fogo: Contos e Memórias da Guerra de Espadas na Bahia
Authors: CEZARINHO Filipe Arnaldo , DOURADO Tábata Figueiredo
Published: April 2021

A finalidade deste trabalho é demonstrar o valor histórico, cultural e patrimonial da Guerra de Espadas na Bahia. Os meios para tal foram diversos. Em primeiro lugar, incumbimo-nos de uma pesquisa histórica através da hemeroteca do Centro Nacional de Folclore e Cultura Popular – CNFCP, onde encontramos recortes de jornais que traziam as festas de São João relacionadas às Guerras de Espadas em vários municípios baianos. O critério fundamental era que os verbetes “espadas” e “guerra de espadas” compusessem o conteúdo de cada recorte documental. Os acervos admitem uma linha temporal que vai de 1950 a 1970, podendo encontrar material com datações posteriores.
Yüksek Hızlı Hatlarda Granüler Alt Balast Yerine Asfalt Tabaka Kullanımının Sonlu Elemanlarla Modellenmesi
Authors: GÜRER Cahit , AKILLI TÖRER Tugce , ASLANTAŞ Kubilay
Published: April 2021

Tüm dünyada, konvansiyonel hatlarda olduğu gibi yüksek hızlı demiryolu hatlarında da balastlı üstyapı yaygın olarak kullanılmaktadır. Bununla birlikte yüksek hızlı hatların gelişmesi ve trenlerin yük kapasitelerinin artması demiryolu üstyapısındaki balast ve taban zemini arasındaki granüler tabakalara daha farklı malzemelerden yapılmış alt tabakaların (altbalast) eklenerek projelendirilmesini zorunlu kılmaktadır. Bu sayede demiryolu üstyapısının servis ömrü uzatıldığı gibi bakım maliyetlerinin de düşürülmesi sağlanmış olacaktır. Bu çalışma kapsamında alt balast tabakası yerine asfalt tabaka kullanımı Türkiye’de uygulanan bir tip kesit üzerinde, yüksek hızlı hat dingil yükü ve asfalt malzemenin farklı mevsimlerdeki özelliklerine göre sonlu elemanlar metoduyla (SEM) modellenerek çözümlenmiş ve elde edilen sonuçlar karşılaştırılmıştır. Asfalt kaplamalardan oluşan alt balast tabakalarının yüksek hızlı hatlarda kullanılmasının taban zeminindeki deformasyonları ve gerilmeleri azaltacağı, yol güvenliğinin artmasını sağlayacağı ve her bölgede bulunması güç olan kaliteli balast malzemesine olan ihtiyacı da azaltacağı sonuçlarına ulaşılmıştır.
Yüksek Hızlı Tren Hatlarında Sinyalizasyon Blok mesafelerinin Hesaplanması
Authors: YILDIRIM Selim
Published: April 2021

Raylı ulaşım sistemlerinin hızlı, güvenilir ve emniyetli olabilmesi için sinyalizasyon sistemlerine ihtiyaç vardır. Sinyalizasyon sistemleri geçmişten günümüze birçok değişikliğe uğramış olmasına rağmen temel prensipler her zaman aynı kalmıştır. Kazaların, can ve mal kayıplarının önüne geçebilmek, güvenli işletme sağlayabilmek için trenler arasında belirli bir zaman ve mesafenin olması gerekmektedir. Bu çalışmada yüksek hızlı tren hatlarında sinyal blok mesafeleri hesaplanarak, Ankara-Eskişehir ile Ankara-Konya YHT (Yüksek Hızlı Tren) hatlarındaki blok mesafeleri ile karşılaştırmaları yapılmıştır. Sonuç bölümünde blok mesafelerinin hat kapasitesine etkisi, kurulum ve bakım maliyetleri değerlendirilerek tasarım ve uygulama aşamalarına dair önerilerde bulunulmuştur.
Lamine CFRP Donatılı Traverslerin Deneysel ve Sonlu Eleman Analizleriyle İncelenmesi
Authors: ÇEÇEN Ferhat , AKTAŞ Bekir
Published: April 2021

Günümüz demiryolu işletmeciliğinde artan hız ve aralıksız işletim koşulları sonucunda, daha düşük bakım gerektiren çözümler mecburiyet halini almıştır. Bu çalışmada, en önemli demiryolu yapı elemanlarından biri olan traversler ele alınmıştır. Klasik betonarme traverslerin literatürde geçen çeşitli sorunlarına değinildikten sonra bu sorunların kaynağında çözümlenmesi adına mevcut çelik donatılar yerine karbon fiber takviyeli polimerlerin (carbon fiber reinforced polymers, CFRP) kullanımı araştırılmıştır. CFRP donatı olarak da geleneksel dairesel donatı geometrisi yerine çok daha düşük maliyetli lamine form kullanılmıştır. Üretilen prototiplerde yapılan TS EN 13230-3 statik eğilme testleri ve detaylı ANSYS sonlu eleman analizlerine göre uzun ve verimli servis ömrü açısından oldukça olumlu sonuçlar elde edilmiştir.
Caminho dos afetos pelos territórios da formação em Odontologia
Authors: Batista Beatriz Santos , Tajra Fábio Solon , Viana Patrícia Ferreira de Sousa
Published: April 2021

Deseja-se uma formação contemporânea dos profissionais de saúde baseada na integração entre o ensino, o serviço e a comunidade, desenvolvida nos cenários reais de práticas. Nesse sentido, o objetivo deste trabalho foi analisar o processo de ensino-aprendizagem da formação em Odontologia nas durante as experiências extramurais curriculares. Trata-se de um estudo autobiográfico utilizando como dispositivos ativadores das memórias os diários de campo, mensagens de textos trocadas pelo aplicativo WhatsApp®, fotografias, álbum seriado, mapa de territorialização, genograma familiar e relatos das vivências extramurais. Emergiram duas categorias como resultados da análise dos dados: Possibilidades de ensino-aprendizagem no encontro da teoria com a prática e Mapa dos afetos da formação em Odontologia: expectativas, incertezas e desejos. Considera-se que as experiências extramurais foram capazes de mobilizar afetos e oportunizar a reflexão sobre as práticas de campo, bem como possibilitou reconhecer sua potência transformadora do processo de formação em Odontologia.
Psoriasis y Vitamina D
Authors: Pastore Federico
Published: April 2021

La psoriasis es una enfermedad inflamatoria crónica mediada inmunológicamente, de base genética, que se puede desencadenar o agravar por diferentes factores. La 25-hidroxivitamina D (25[OH]D) tiene efectos antiproliferativos, antiinflamatorios y antiangiogénicos en el organismo.
Análisis de las modificaciones en la estadificación del T según el manual del American Joint Committee on Cancer. ¿Cómo cambia nuestro manejo de los pacientes?
Authors: Parigini Aníbal M. , De Diego María Clara , Valdez Raúl , Busso Corina
Published: April 2021

Antecedentes: En la octava edición del manual de estadificación del cáncer del American Joint Committee on Cancer (AJCC), se introdujeron cambios importantes en las categorías T, N y M. Al entrar en vigencia la octava guía de la AJCC,se modificó no solo el T, sino también la indicación de biopsia del ganglio centinela (BGC).
Entre los cambios más significativos en la estadificación se encuentran: la exclusión del índice mitótico (IM) de la categoría T en los melanomas finos (de hasta 1 mm de espesor) y el cambio del punto de corte para el espesor tumoral para discriminar un T1a (< 0,8 mm sin ulceración) de un T1b (≥ 0,8 mm).
Objetivo: Comparar la estadificación inicial de los melanomasfinos según el criterio utilizado en la séptimaedición, con la que tendrían de acuerdo con la perspectiva actualdel AJCC, con especial atención en el índice mitótico.
Diseño y métodos: Estudio observacional, de corte transversal, realizado mediante la recolección de datos de las historias clínicas desde el 1 de enero de 2000 hasta el 31 de diciembre de 2017.
Resultados: De 131 melanomas finos incluidos, 28 tendrían cambios en su estadificación. Al considerar el nuevo punto de corte para el espesor tumoral, 22 melanomas T1a pasarían a T1b. Asimismo, se detectaron 20 melanomas con un IM ³1 mitosis/mm2, de los cuales solo 6 tuvieron indicación de BGC por este criterio exclusivamente y serían clasificados como T1a en la actualidad. De estos, en 2 no se realizó la BGC por autodeterminación delos pacientes y en los 4 restantes el resultado fue negativo.
Conclusiones: Veintiocho de nuestros pacientes tendrían hoy diferencias en la indicación de BGC: 22 serían considerados con mayor riesgo de metástasis ganglionares y serían candidatos a su pesquisa. Los otros 6 pacientes ya no tendrían indicación de ese estudio por la baja posibilidad de encontrar metástasis ocultas, lo cual coincide con el resultado negativo de la BGC en los 4 pacientes que se sometieron al procedimiento.
Poroqueratosis de Mibelli en la edad pediátrica
Authors: Cazorla María Belén , Müller Gisela , Yarza Mónica , Navacchia Daniel , Grees Susana
Published: April 2021

Las poroqueratosis son un grupo heterogéneo de trastornos de la queratinización epidérmica, de presentación infrecuente. Se caracterizan clínicamente por pápulas hiperqueratósicas que confluyen formando placas anulares con un centro atrófico y bordes sobreelevados. Hay seis variantes clínicas. El examen histopatológico evidencia la característica laminilla cornoide. Se presenta el caso de una niña de 2 años con diagnóstico de poroqueratosis de Mibelli y respuesta parcial al tratamiento tópico con tretinoínaal 0,025%, que actualmente continúa en seguimiento clínico.
Síndrome de Sézary. Tratamiento
Authors: Alonso Bárbara , Arias Mariana , Abeldaño Alejandra
Published: April 2021

El síndrome de Sézary (SS) es una variante leucémica del linfoma cutáneo de células T con mal pronóstico, que requiere un abordaje multidisciplinario. El tratamiento es paliativo, ya que no se conocela curación para esta enfermedad. El objetivo terapéutico es reducir al mínimo las recurrencias y preservar la calidad de vida y la supervivencia global. Si bien se cuenta con numerosas opciones, las terapias inmunomoduladoras son las de elección. La quimioterapia se reserva para los casos refractarios o ante la progresión de la enfermedad.
Paniculitis histiocítica citofágica con remisión espontánea
Authors: Bertani Fiorella , López Di Noto Ada Laura , Weintraub Laura , Sánchez Graciela , Merola Gladys
Published: April 2021

La paniculitis histiocíticacitofágica es una patología que afecta principalmente la porción lobulillar del tejido adiposo, poco frecuente y documentada. La mayoría de los casos se asocian a un síndrome hemofagocítico, de curso rápido, afectación visceral y desenlace mortal. En menor proporción, puede tener una presentación limitada a la piel, como en este caso. Se presenta a una paciente con diagnóstico de paniculitis histiocíticacitofágicano asociada a síndrome hemofagocítico, con remisión espontánea del cuadro y seguimiento desde hace 11 años.
Dermatitis atópica. Comorbilidades
Authors: Pastore Federico
Published: April 2021

Los pacientes con dermatitis atópica pueden desarrollar otras comorbilidades alérgicas, así como infecciones bacterianas y virosis cutáneas y extracutáneas, en ocasiones, severas. Con menor frecuencia, se señalan otras patologías que deben investigarse, como afecciones neuropsiquiátricas: ansiedad, depresión; obesidad, diabetes tipo 2; cardiopatías: infarto de miocardio, coronariopatías; neoplasias, en especial linfomas; enfermedades autoinmunes: gastroenteritis inmunes, enfermedad deCrohn, colitis ulcerosa, celiaquía; alopeciaareata.
Conducta expectante en el queratoacantoma solitario
Authors: Kuperman Wilder Lola , Foenquinos Romina , Acosta Ana Clara , Chiappe César
Published: April 2021

El queratoacantoma solitario es un tumor queratinocítico localizado en zonas fotoexpuestas que se caracteriza por tener tres fases evolutivas: una primera de crecimiento rápido, una de estabilidad y una final de involución espontánea. Esta última no se observa con tanta frecuencia porque su diagnóstico diferencial, el carcinoma espinocelular, obliga a que la terapia de elección sea la escisión quirúrgica. La decisión de mantener una conducta expectante debe tomarse en conjunto con el paciente, quien debe conocer los riesgos que esta implica. Presentamos los casos de 2 pacientes que rechazaron la opción quirúrgica y tuvieron una evolución favorable con una estricta supervisión clínica.
Micobacteriosis atípica de distribución esporotricoide
Authors: Reichardt Melanie , Radonich Jesica , Buffetti Martina , Carabajal Graciela , Mazzini Miguel A.
Published: April 2021

Las micobacterias atípicas o no tuberculosas son un conjunto de especies integrado por más de 150 variedades. Se caracterizan por su amplia distribución en la naturaleza. En ocasiones, resultan patógenas para el ser humano y pueden producir desde afectación pulmonar, linfadenitis, infección de catéteres y enfermedad diseminada hasta infecciones de la piel y los tejidos blandos. Se presentan los casos de dos pacientes con infecciones cutáneas causadas por Mycobacterium marinum y Mycobacterium chelonae, ambos con clínica de distribución esporotricoide, con buena respuesta al tratamiento instaurado.
Siringomas vulvares tratados con ácido tricloroacético
Authors: De Lena Florencia , Itatí Cordo María Victoria , Pereira Valeria , Torchiari Fabricio , Martínez Etchevest Sandra
Published: April 2021

Los siringomas son tumores anexiales benignos derivados de la porción ductal de las glándulas sudoríparas ecrinas. Son frecuentes en las mujeres en edad reproductiva y su localización habitual es la periorbital. La presentación en mujeres posmenopáusicas y la localización en la vulva son infrecuentes.

Si bien se cuenta con numerosos tratamientos, ninguno es de primera línea.

Se analiza el caso de una paciente posmenopáusica que presentaba pápulas pruriginosas en la vulva. La histopatología confirmó el diagnóstico de siringomas. Se realizó el tratamiento tópico con ácido tricloroacético al 90%, con buena respuesta.
Placas y pápulas erosivas en los pliegues
Authors: Miraglia Eugenia , Gerez Eliana Maribel , Garritano María Victoria , Maradeo María Roxana
Published: April 2021

Una mujer de 23 años, con antecedentes de infección por HIV diagnosticada en 2012, que seguía un tratamiento antirretroviral errático, el cual reinició hacía 3 meses, consultó a nuestro servicio por lesiones cutáneas distribuidas en los pliegues, de un mes de evolución.
Actualización bibliográfica: Inmunocriocirugía, una alternativa terapéutica en los carcinomas basocelulares invasores
Authors: Mariucci Vázquez María Belén
Published: April 2021

El carcinoma basocelular es la neoplasia maligna más prevalente y una patología muy frecuente de consulta dermatológica.

La cirugía convencional y la cirugía micrográfica de Mohs representan la primera opción de tratamiento, pero se cuenta con numerosas alternativas de segunda línea como el tratamiento tópico con 5-fluorouracilo o con imiquimod, la criocirugía y la terapia fotodinámica, con menores tasas de respuesta y mayores tasas de recidiva.
Features of management methodology for assessing the effectiveness of state programs of the constituent entities of the Russian Federation
Authors:   Financial University under the Government of the Russian Federation, PAVLOVA Irina
Published: April 2021

The article considers the main approaches of analyzing the effectiveness of state programs of the constituent entities of the Russian Federation and conducted a comparative characterization of the features of the methodology for assessing the effectiveness of state programs of individual constituent entities of the Russian Federation.
Legal regulation of measures for the use and protection of forests
Authors:   Bashkir Institute of Social Technologies (branch) of the Academy of Labor and Social Relations, IKSANOV Radmir , VLADIMIROV Igor ,   Institute of Law Bashkir State University
Published: April 2021

Forest violations are a special type of offenses that infringe on the order of rational nature management and environmental protection. The purpose of this study is to analyze legal measures for the use and protection of forests. The relevance of the work lies in the fact that the problem of legal protection of forests is manifested in the mechanism of exercising the powers of forest protection by the constituent entities of the Russian Federation, therefore, the solution to this problem should be developed and implemented by the efforts of state bodies, public associations and the local population. The paper lists the problems of the legal mechanism of forest protection, defines its subjects, discloses the problems in the field of control and supervision activities by forest users.