Abstract This article describes the effect of CO2 LBW performance parameters for the welded joint of 1.5 mm thin sheet of Nimonic 80A superalloy. Superalloy 80A used in high temperature application as aero-engine components- blade, rings, exhaust gas turbine part, nuclear tube support and automobile valve. The study focused on optimizing the welding process for the welded joints. Here, LP, WS, FD, and shielding GR will be optimised to improve the weld quality of Nimnic 80A material. Two different optimization techniques were used. The first method is SOO, which is based on the S/N ratio. The aim of this method is to find the Single-optimal values of process parameters. The second method employed MOO, combining the Taguchi grey relational analysis (TGRA) with the principal component analysis (PCA) technique. The researchers used these methods in an effort to identify the set of parameters for obtaining improved weld quality. Authors find best setting parameters p3-v3-f3-g1, with the specific parameter values are LP 2400 W, WS 1800 mm/min, FD 18 mm, and GR 10 lpm. The optimized parameters have yield significant improvements in the depth of penetration 6.03%, weld bead 8.74%, Vickers hardness 12.5%, and tensile strength 16.48% by using TGRA coupled with PCA. CO 15 1 5 1. A superalloy aeroengine aero engine components blade rings part valve joints Here material SOO SN S N ratio Singleoptimal Single optimal MOO (TGRA PCA (PCA technique p3v3f3g1, p3v3f3g1 pvfg p3 v3 f3 g1, g1 p v f g p3-v3-f3-g1 240 W 180 mmmin min mm/min lpm 603 6 03 6.03% 874 8 74 8.74% 125 12 12.5% 1648 16 48 16.48 p3v3f3g p3-v3-f3-g 24 60 0 6.03 87 7 8.74 12.5 164 4 16.4 2 6.0 8.7 12. 16. 6. 8.

ABSTRACT Introduction: Approximately 55.52% of the Indian population had been fully vaccinated by Jan. 2022, since its first roll out on January 16, 2021. A few concerns were raised concerning the Covishield vaccination related to thrombotic thrombocytopenia. Apheresis-derived platelet concentrates are frequently required in a plethora of clinical situations and post-vaccination decrement of platelet counts might lead to increased deferral of the plateletpheresis donors. Objectives. The aim of the study was to discover the effect of the Covishield vaccination on deferral rates of plateletpheresis donors. Methods: Blood samples were collected from the potential platelet donors for the completion of the standard questionnaire for the complete blood count. The data collected were tabulated in the MS Excel spreadsheet and the biostatistical analysis was performed with the SPSS v23. A p-value of < 0.05 was taken as significant. We compared this data with age-and sex-matched controls. Results: The mean age of cases and controls was 29.69 ± 8.57 and 30.15 ± 7.11, respectively. There was a significant difference in platelet counts of cases (188496.35 ± 72065.66/cumm) and controls (269524.50 ± 53981.60/cumm). Furthermore, donors who received one dose had higher platelet counts of 248676.47 ± 80075.24/cumm than those who received both doses of vaccine (179970.83 ± 66773.73/cumm). The difference in deferral rates between the two groups was remarkable (34.7% vs. 0.9%, with the p-value < 0.001). Conclusion: Vaccination certainly increased the deferral rates of plateletpheresis donors due to low platelet counts. Average platelet counts were low in fully vaccinated individuals, however, the platelets returned to normal counts as the post-vaccination days progressed. Introduction 5552 55 52 55.52 Jan 2022 16 2021 thrombocytopenia Apheresisderived Apheresis derived postvaccination post Objectives Methods count v23 v pvalue p value 005 0 05 0.0 ageand sexmatched sex matched Results 2969 29 69 29.6 857 8 57 8.5 3015 30 15 30.1 711 7 11 7.11 respectively 188496.35 18849635 188496 35 (188496.3 72065.66/cumm 7206566cumm cumm 72065 66 269524.50 26952450 269524 50 (269524.5 53981.60/cumm. 5398160cumm 53981.60/cumm . 53981 60 53981.60/cumm) Furthermore 24867647 248676 47 248676.4 8007524cumm 80075 24 179970.83 17997083 179970 83 (179970.8 66773.73/cumm. 6677373cumm 66773.73/cumm 66773 73 66773.73/cumm) 34.7% 347 34 (34.7 vs 09 9 0.9% 0.001. 0001 0.001 001 0.001) Conclusion individuals however progressed 555 5 55.5 202 1 v2 00 0. 296 2 6 29. 85 8. 301 3 30. 71 7.1 188496.3 1884963 18849 (188496. 7206 269524.5 2695245 26952 (269524. 5398 2486764 24867 4 248676. 8007 179970.8 1799708 17997 (179970. 6677 34.7 (34. 0.9 000 0.00 55. 20 7. 188496. 1884 (188496 720 269524. 2695 (269524 539 2486 800 179970. 1799 (179970 667 34. (34 188 (18849 72 269 (26952 53 248 80 179 (17997 (3 18 (1884 26 (2695 17 (1799 ( (188 (269 (179 (18 (26 (17 (1 (2

ABSTRACT Introduction: During pregnancy, the iron requirement increases to meet the optimal growth of the fetus and prevent iron deficiency anemia-related complications in the mother. However, in sickle cell disease (SCD) primarily due to repeated blood transfusions and hemolysis-induced recycling of iron, its supplementation during pregnancy remains questionable and may be harmful. Methods: Twenty-five pregnant women with homozygous SCD and 25 pregnant women with normal hemoglobin variants were included as cases and control, respectively. Pregnancy and sickle cell anemia (SCA) were diagnosed using standard protocols. The serum iron, serum ferritin, total iron-binding capacity (TIBC), percentage transferrin saturation and C-reactive protein were estimated, as per the manufacturer’s protocol. The complete blood count was performed. The unpaired ‘t-test’ was performed using the SPSS v23.0 and the principal component analysis (PCA) was performed using the online software MetaboAnalyst for statistical analysis. Main Results: The studied cases had significantly lower mean hemoglobin and higher mean corpuscular volume (MCV), compared to controls. The mean serum-iron, serum-ferritin and percentage transferrin-saturation in the cases were significantly higher than that of the controls, while the TIBC was lower in the cases (p < 0.0001). The mean level of serum iron, ferritin, percentage transferrin saturation and TIBC were 309.44 ± 122.40mcg/dl, 860.36 ± 624.64ng/ml, 42.6 ± 17.30% and 241.32 ± 96.30 mcg/dl, respectively, in the cases and 95.36 ± 41.90mcg/dl, 122.28 ± 49.70ng/ml, 15.83 ± 3.10% and 492.6 ± 149.40mcg/dl in the controls, respectively. Higher MCV, mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) with lower hemoglobin (Hb) were noted in the cases. The PCA revealed that the cases were more heterogeneous in terms of the variability of the iron status and hematological indices than the controls. Conclusion: The current study shows iron sufficiency in most cases of pregnancy with SCA and suggests that evaluation of iron status must be made before initiating iron prophylaxis in pregnant women with SCA, especially in regions having a high prevalence of sickle cell hemoglobinopathy. Introduction anemiarelated related mother However (SCD hemolysisinduced hemolysis induced harmful Methods Twentyfive Twenty five 2 control respectively (SCA protocols ferritin ironbinding binding TIBC, , (TIBC) Creactive C reactive estimated manufacturers manufacturer s protocol ‘ttest ttest ‘t test t ‘t-test v230 v v23 0 v23. (PCA Results MCV (MCV) controls serumiron, serumiron serum-iron serumferritin transferrinsaturation p 0.0001. 00001 0.0001 . 0001 0.0001) 30944 309 44 309.4 12240mcgdl mcgdl 122 40mcg dl mcg 122.40mcg/dl 86036 860 36 860.3 62464ngml ngml 624 64ng ml ng 624.64ng/ml 426 42 6 42. 1730 17 30 17.30 24132 241 32 241.3 9630 96 96.3 mcg/dl 9536 95 95.3 4190mcgdl 41 90mcg 41.90mcg/dl 12228 28 122.2 4970ngml 49 70ng 49.70ng/ml 1583 15 83 15.8 310 3 10 3.10 4926 492 492. 14940mcgdl 149 MCH (MCH MCHC (MCHC Hb (Hb Conclusion hemoglobinopathy (TIBC v2 (MCV 0000 0.000 000 3094 4 309. 12 8603 86 860. 62 173 1 17.3 2413 24 241. 963 9 96. 953 95. 1222 122. 158 8 15. 31 3.1 14 0.00 00 17. 3. 0.0 0.

ABSTRACT Objective: To compare the initial stress distribution and displacement on mandibular dentition using extra and inter-radicular mini-implants for arch distalization, by means of finite element analysis. Methods: For this study, two finite element models of the mandible were designed. The models consisted of periodontal ligament (PDL) and alveolar bone of all teeth until second molars. In the Case 1, bilateral extra-radicular buccal-shelf stainless steel mini-implants (10.0-mm length; 2.0-mm diameter) were placed between first and second permanent molars. In the Case 2, bilateral inter-radicular stainless steel mini-implants (10.0-mm length; 1.5-mm diameter) were placed between second premolar and first permanent molar. Power hook was attached between canine and first premolar at a fixed height of 8mm. In the two cases, 200g of distalization force was applied. ANSYS v. 12.1 software was used to analyze and compare von Mises stress and displacement in the mandibular dentition, PDL and bone. Results: Higher stresses were observed in mandibular dentition with the inter-radicular implant system. The amount of von Mises stress was higher for cortical bone (85.66MPa) and cancellous bone (3.64MPa) in Case 2, in comparison to cortical bone (41.93MPa) and cancellous bone (3.43MPa) in Case 1. The amount of arch distalization was higher for mandible in Case 1 (0.028mm), in comparison to Case 2 (0.026mm). Conclusion: Both systems were clinically safe, but extra-radicular implants showed more effective and controlled distalization pattern, in comparison to inter-radicular implants, in Class III malocclusion treatment. Objective interradicular inter radicular miniimplants mini analysis Methods study designed (PDL molars extraradicular buccalshelf buccal shelf 10.0mm 100mm mm 10.0 10 0 length 2.0mm 20mm 2.0 diameter 1.5mm 15mm 1.5 5 molar 8mm cases g applied v 121 12 12. Results system 85.66MPa 8566MPa MPa 85 66MPa (85.66MPa 3.64MPa 364MPa 3 64MPa (3.64MPa 41.93MPa 4193MPa 41 93MPa (41.93MPa 3.43MPa 343MPa 43MPa (3.43MPa 0.028mm, 0028mm 0.028mm , 028mm (0.028mm) 0.026mm. 0026mm 0.026mm . 026mm (0.026mm) Conclusion safe pattern treatment 0mm 100 10. 20 2. 5mm 15 8 4 (0.028mm (0.026mm

RESUMO Objetivo: Comparar a distribuição da tensão inicial e o deslocamento na dentição inferior usando mini-implantes extra e inter-radiculares para distalização da arcada, por meio da análise de elementos finitos. Métodos: Dois modelos de elementos finitos da mandíbula foram criados, os quais consistiram de ligamento periodontal (PDL) e osso alveolar de todos os dentes até os segundos molares. No Caso 1, mini-implantes extra-radiculares de aço inoxidável (10,0 mm de comprimento; 2,0 mm de diâmetro) foram colocados bilateralmente na buccal-shelf entre o primeiro e o segundo molares permanentes. No Caso 2, mini-implantes de aço inoxidável inter-radiculares (comprimento de 10,0 mm; diâmetro de 1,5 mm) foram colocados bilateralmente entre o segundo pré-molar e o primeiro molar permanentes. Um Power hook foi preso entre o canino e o primeiro pré-molar a uma altura fixa de 8mm. Nos dois casos, foi aplicada força de distalização de 200g. O software ANSYS v. 12.1 foi usado para analisar e comparar a tensão de von Mises e o deslocamento na dentição inferior, ligamento periodontal e osso. Resultados: Maiores tensões foram observadas na dentição inferior com o sistema de implantes inter-radiculares. A quantidade de tensões de von Mises foi maior para osso cortical (85,66MPa) e osso esponjoso (3,64MPa) no Caso 2, em comparação com osso cortical (41,93MPa) e osso esponjoso (3,43MPa) no Caso 1. A quantidade de distalização da arcada inferior foi maior no Caso 1 (0,028 mm), em comparação com o Caso 2 (0,026 mm). Conclusão: Ambos os sistemas foram clinicamente seguros, mas os implantes extra-radiculares mostraram um padrão de distalização mais eficaz e controlado, em comparação com os implantes inter-radiculares, para tratamento da má oclusão de Classe III. Objetivo miniimplantes mini interradiculares inter radiculares Métodos criados PDL (PDL extraradiculares 100 10 0 (10, comprimento 20 buccalshelf buccal shelf permanentes 10, 15 5 prémolar pré 8mm casos 200g g v 121 12 12. Resultados interradiculares. radiculares. 85,66MPa 8566MPa MPa 85 66MPa (85,66MPa 3,64MPa 364MPa 3 64MPa (3,64MPa 41,93MPa 4193MPa 41 93MPa (41,93MPa 3,43MPa 343MPa 43MPa (3,43MPa 0,028 0028 028 (0,02 mm, , 0,026 0026 026 mm. . Conclusão seguros controlado interradiculares, radiculares, III (10 8 4 0,02 002 02 (0,0 (1 0,0 00 (0, ( 0, (0

Resumo Objetivo Analisar os resultados clínicos, radiológicos e funcionais da fratura do planalto tibial (Schatzker Tipo V, VI) tratada com fixador externo do anel Illizarov com ou sem abertura mínima. Métodos Um total de 52 fraturas do planalto tibial dos tipos V e VI foram tratadas com fixador externo do anel Ilizarov com ou sem fixação interna mínima. A avaliação do desfecho funcional foi feita utilizando-se o escore da American Knee Society (AKS, na sigla em inglês) com consolidação clínica, radiológica e complicações encontradas. Resultados Foram 37 (71,15%) pacientes do sexo masculino e 15 (28,84%) do sexo feminino, com idade média de 39,07 ± 12,58 anos. Acidentes de trânsito (ATs) foram a principal causa das fraturas, contabilizando 32 casos (61,53%), seguidos por lesão por queda, com 16 casos (30,76%), e impacto direto, com 4 casos (7,69%). Foram 21 (40,38%) casos de fraturas tipo V, 31 (59,61%) casos do tipo VI e 24 (46,15%) casos de fratura exposta. Os escores médios da AKS para as fraturas tipo V e VI foram de 82,8 e 80,70, respectivamente, mas não foi estatisticamente significativo em p <0,05. O escore médio da AKS para fraturas fechadas e abertas também não foi estatisticamente significativo em p <0,05. Conclusões Para a fratura do planalto tibial complexa dos tipos V e VI de Schatzker, a fixação externa de Ilizarov é um método de tratamento seguro, econômico e eficiente que resulta em resultados satisfatórios.

Abstract Objective To analyze the results of clinical, radiological, and functional outcomes of tibial plateau fracture (Schatzker Type V, VI) treated with Illizarov ring external fixator with or without minimum opening. Methods A total of 52 tibial plateau fractures of type V, VI were treated with Ilizarov ring external fixator with or without mininum internal fixation were studied. Functional outcome assessment was done using the American Knee Society (AKS) score with clinical, radiological union, and complications were analyzed. Results There were 37 (71.15%) male and 15 (28.84%) female patients, with a mean age of 39.07 ± 12.58 years old. Road traffic accidents (RTAs) were the major cause of fracture, accounting for 32 cases (61.53%) followed by fall injury, with 16 cases (30.76%), and direct impact, with 4 cases (7.69%). Twenty-one (40.38%) cases were type V and 31 (59.61%) cases were type VI fractures, and there were 24 (46.15%) cases of open fracture. The mean AKS score of Type V and Type VI fractures were 82.8 and 80.70, respectively, but this was statistically not significant at p<0.05. The mean AKS score of closed and open fractures were also statistically not significant at p<0.05. Conclusions For Schatzker Types V and VI complex tibial plateau fractures, Ilizarov external fixation is a safe, cost-effective and efficient treatment method that presents a satisfactory outcome.

Abstract In this paper, we define the space Sα θ (∆m v, f) of all (∆m v, f)-lacunary statistical convergent sequences of order α with the help of unbounded modulus function f, lacunary sequence (θ), generalized difference operator ∆ m v and real number α ∈ (0, 1]. We also introduce the space ωα θ (∆m v, f) of all strong (∆m v, f)-lacunary summable sequences of order α. Properties related to these spaces are studied. Inclusion relations between spaces Sα θ (∆m v, f) and ωα θ (∆m v, f) are established under certain conditions.

Abstract The aqueous solubility of cefixime trihydrate (a water insoluble drug) using different hydrotropic agents was determined and solid dispersions of cefixime trihydrate were prepared by hydrotropic solubilization technique. The drugs content were determined. The aqueous solubility of v was increased many fold in presence of sodium acetate trihydrate as hydrotropic agent. This hydrotropic agent was used to prepare solid dispersion of cefixime trihydrate. Cefixime trihydrate and sodium acetate trihydrate were accurately weighed and taken in a 200 mL beaker. Distilled water 10-15 mL was taken to dissolve hydrotropic agent using heat (48-50 °C). The drug was then added to it and magnetically stirred till whole mass get viscous. The solid dispersions of cefixime trihydrate were characterized by XRD, DSC and IR studies. DSC thermogram, XRD and Infra-Red spectra were studied. Solid dispersions, thus prepared, showed faster release of the drug as compared to pure drug and physical mixture.

Abstract Radioactive trivalent chromium (51Cr3+) is a known radiopharmaceutical used to tag plasma proteins, platelets and also for estimation of blood volume. Nevertheless, there exist insufficient reports with limited sample sizes concerning its clearance from blood and its biodistribution after intravenous administration. This study focused to understand clearance rate of 51Cr3+ from blood and analyze its biodistribution. For biodistribution, six adult New Zealand white albino rabbits were injected with 51Cr3+ through their marginal vein. Percentage clearance of 51Cr3+ from blood was calculated by recording radioactive counts obtained at 1, 58, 61, 120, 180 and 240 minutes post-administration in thirty-three adult New Zealand white albino rabbits. For evaluating 51Cr3+ biodistribution, organs were surgically removed from the rabbits and weighed. Radioactivity of the organs and urine were counted in a nucleonix gamma-ray spectrometer with a NaI scintillation detector. Data were expressed as cps/g. Average clearance of 51Cr3+ was 34% from the first to the 58 minute. Subsequent measurements for hourly clearance at 120, 180 and 240 minutes showed percentage reduction of radioactivity of 33, 14 and 8, respectively. Minimal specific activities were found in the muscle and brain. Spleen, lungs, liver and kidneys exhibited moderate radioactivity. Urine tracer-concentrations were found to be ten times more than that of plasma. From this study, it has been observed that clearance of 51Cr3+ from blood was faster initially which slowed down progressively and there displayed moderate uptake of 51Cr3+ by certain organs. Understanding pharmacokinetics of 51Cr3+ is relevant for its potential use as a diagnostic tool.

A tractor-operated automatic gun sprayer was developed for a cotton crop. The unit consists of frame structure, spray tank, horizontal triplex pump, control valves, spray gun nozzle, pressure gauge, strainer, hydraulic agitator and actuating mechanism. The power to drive the HTP pump was taken from the tractor power take off (PTO) through a belt and pulley. The actuating mechanism consists of motor and worm gear reduction. Two motors with 0.5 kW each (12 V dc) were used to provide oscillation motion to spray guns and motors get power from the tractor battery. The rotation angle of the spray gun is 30° horizontally. Provision was also made to fold the spray boom while in transport. The spray pattern could be adjusted based on the application of chemicals. This study was conducted to determine the suitable nozzle orientation (0°, 15° and 30° downwards) to field crops. The orientation of the spray nozzle was maintained by using the metal protractor. The laboratory experiments were carried out by using the actual cotton plant. The best nozzle orientation for maximum droplet density and droplet size as 15° downward. Leaf hopper [Amrasca biguttula (Ishida)] and aphids [Aphis gossypii (Glover)] control in the cotton crop after 7th day of spraying dinotefuran insecticide from the automatic gun sprayer and conventional tractor-operated gun sprayer was 87, 86 and 58 %, and 50 %, respectively. The total cost required to fabricate the sprayer was US$ 1008. The cost of operation of the tractor operated automatic gun sprayer was found to be US$ 4.7/ ha.

Abstract Objectives To evaluate different types of perianal fistulas and their complications on magnetic resonance imaging (MRI) and to compare plain, contrast, and jelly magnetic resonance fistulography findings. Materials and Methods This prospective study was performed in 30 patients who presented with perianal pus discharge or external fistulous opening. Magnetic resonance imaging of the perianal region before and after giving intravenous contrast and after injecting jelly through a percutaneous opening was performed on a 3T scanner and the results were correlated. Results The mean age of the patients was 40.13±13.88 years (range 19-75 years). The male to female ratio was 14:1. The most common type of fistula was St. James classification type I, which was seen in 13 patients (43%), followed by type IV in 30%, type III in 16%, type II in 6.66%, and type V in 3.33% of the patients. Using agreement analysis, we compared the number of primary and secondary tracts, internal openings, and horseshoe tracts and found a significant agreement between plain and post Jelly MRI fistulography (kappa statistic close to 1).When comparing plain and contrast MRI, there was significant agreement in the primary and secondary tracts, while statistically insignificant results were obtained (p>0.05) for the horseshoe tract and internal openings. Contrast injection was helpful in 7 subjects (23.3%) as peripheral enhancement of abscesses were better delineated. Conclusion Magnetic resonance imaging is the one stop diagnostic modality for perianal fistulas. Acquisition of axial (Ax) T2, axial T2 FS, coronal T2 and coronal T2 FS sequences without administering intravenous contrast or jelly is usually sufficient for the diagnosis of fistulas and their complications.

Abstract For a given graph G, its line graph denoted by L(G) is a graph whose vertex set V (L(G)) = E(G) and {e1, e2} ∈ E(L(G)) if e1 and e2 are incident to a common vertex in G. Let R be a finite commutative ring with nonzero identity and G(R) denotes the unit graph associated with R. In this manuscript, we have studied the line graph L(G(R)) of unit graph G(R) associated with R. In the course of the investigation, several basic properties, viz., diameter, girth, clique, and chromatic number of L(G(R)) have been determined. Further, we have derived sufficient conditions for L(G(R)) to be Planar and Hamiltonian.

Abstract Let G = (V,E) be a simple graph. An edge e ∈ E(G) edge-vertex dominates a vertex v ∈ V (G) if e is incident with v or e is incident with a vertex adjacent to v. A subset D ⊆ E(G) is an edge-vertex dominating set of a graph G if every vertex of G is edge-vertex dominated by an edge of D. A vertex cover of G is a set C ⊆ V such that for each edge uv ∈ E at least one of u and v is in C. We characterize trees with edge-vertex domination number equals vertex covering number.

Abstract A vertex-edge Roman dominating function (or just ve-RDF) of a graph G = (V, E) is a function f : V (G) → {0, 1, 2} such that for each edge e = uv either max{f (u), f (v)} ≠ 0 or there exists a vertex w such that either wu ∈ E or wv ∈ E and f (w) = 2. The weight of a ve-RDF is the sum of its function values over all vertices. The vertex-edge Roman domination number of a graph G, denoted by γ veR (G), is the minimum weight of a ve-RDF G. We characterize trees with vertexedge roman domination number equal to twice domination number minus one.

Abstract. The electrochemical studies of picric acid were carried out in acidic, neutral and basic buffer media at bare glassy carbon (GC) and polypyrrole modified GC electrode. Cyclic Voltammogram (CV) of picric acid exhibited three reduction peaks at -0.4, -0.8 and -1.5V (vs. Ag/AgCl) and two oxidation peaks at 0.8 and 1.4V (vs. Ag/AgCl). Among the various pH studied, highly sensitive response was observed at pH 1.0. The effect of scan rate was studied between 25 and 500 mVs-1 at the optimal pH.CV results revealed the adsorption-controlled reaction at the electrode surface. The GC electrode was modified with polypyrrole conducting polymer film to enhance the electrocatalytic activity of the reductive species. Atomic force microscopy (AFM) images showed the nanosphere morphology of the polypyrrole film, which was coated uniformly on the electrode surface. Under optimum experimental conditions, the influence of concentration on the stripping signal was studied. The linear range of detection was found between 50 ppb and 250 ppb with the lower limit of detection of 10±3 ppb.

Resumen. Los estudios electroquímicos del ácido pícrico se realizaron en medios amortiguados ácidos, neutros y alcalinos con un electrodo de carbono vítreo (GC) y de GC modificado con polipirrol (PP). El voltamperograma cíclico (CV) del ácido pícrico mostró tres picos de reducción a -0.4, -0.8 y -1.5 V (frente a Ag/AgCl) y dos picos de oxidación a 0.8 y 1.4 V (frente a Ag/AgCl). Entre los diversos valores de pH estudiados, se observó una respuesta altamente sensible a pH de 1.0. El efecto de la velocidad de barrido se estudió entre 25 y 500 mVs-1 en el pH óptimo. Los resultados de CV revelaron que la reacción está controlada por adsorción en la superficie del electrodo. El electrodo de GC fue modificado con una película polimérica conductora de PP para mejorar la actividad electrocatalítica de las especies. Las imágenes de la microscopía de fuerza atómica (AFM) mostraron la morfología de la nanoesfera de la película de PP, que recubre uniformemente la superficie del electrodo. Bajo condiciones experimentales óptimas, se estudió la influencia de la concentración en la señal de stripping. El rango lineal de detección se encontró entre 50 ppb y 250 ppb con el límite inferior de detección de 10±3 ppb.

Abstract: A vertex v of a graph G = (V,E) is said to ve-dominate every edge incident to v, as well as every edge adjacent to these incident edges. A set S ⊆ V is a vertex-edge dominating set if every edge of E is ve-dominated by at least one vertex of S. The minimum cardinality of a vertex-edge dominating set of G is the vertex-edge domination number γve(G) . In this paper we prove (γt(T)−ℓ+1)/2 ≤ γve(T) ≤(γt(T)+ℓ−1)/2 and characterize trees attaining each of these bounds.